*****TBD*****

This subclass is indented under the class definition. Subject matter wherein different types of conversions are cascaded or combined without intermediate conversion to D.C.

(1) Note. The conversions must be of the type classifiable in this class. That is, the system must be within the class definition and include means to effect a differing sequence or combination of at least two of the following operations: 1. Current conversion; 2. Phase conversion; 3. Frequency conversion

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15+,	34+, for diverse conversion with intermediate conversion to D.C.

2	. Current and phase (e.g., D.C. -Ph₁ -Ph₂):

This subclass is indented under subclass 1. Subject matter wherein the system includes current conversion and phase conversion.

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13+,	for current conversion systems.
148+,	for phase conversion systems.

3	.. Phase 1 to phase 2 to D.C.:

	This subclass is indented under subclass 2. Subject matter wherein A. C. of one phase is converted to A.C. of another phase which is then converted to D.C.

4	... Single phase to polyphase to D.C.:

	This subclass is indented under subclass 3. Subject matter wherein single phase A.C. is converted to polyphase A.C. which is then converted to D.C.

5	... With interphase transformer:

This subclass is indented under subclass 3. Subject matter wherein an interphase transformer is provided in the polyphase circuit.

(1) Note. See subclass 64 for definition of an interphase transformer.

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64,	for current conversion systems operating without phase conversion which include an interphase transformer.

6	.... Including plural anode/single cathode device:

This subclass is indented under subclass 5. Subject matter wherein the system includes a device having multiple anodes, but only a single cathode.

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66,	for current conversion systems including plural anode/single cathode devices; and subclass 168 for frequency conversion systems including plural anode/single cathode devices.

7	... With dynamic rectifier in phase 2 to D.C. stage (e.g., commutator type):

This subclass is indented under subclass 3. Subject matter wherein a dynamic rectifier is provided for converting the phase 2 A.C. to D.C.

(1) Note. A dynamic converter is a converter having mechanical moving parts.

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102+,	for dynamoelectric machine current conversion.
108,	for current conversion by circuit interrupter, rotating rectifier type conversion systems.

8	. Current and frequency (e.g., f₁-f₂-D.C.):

This subclass is indented under subclass 1. Subject matter wherein the system includes current and frequency conversion and frequency conversion.

(1) Note. See the class definition, Glossary, for definitions of current conversion and frequency conversion.

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13+,	for current conversion systems.
157+,	for frequency conversion systems.

9	. Combined phase and frequency conversion (i.e., Ph₁f₁-Ph₂f₂):

This subclass is indented under subclass 1. Subject matter wherein the system includes phase and frequency conversion.

(1) Note. See the class definition Glossary, for definitions of phase conversion and frequency conversion.

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148+,	for phase conversion systems.
157+,	for frequency conversion systems.

10	.. By semiconductor device converter:

This subclass is indented under subclass 9. Subject matter wherein the converter means includes a semiconductor device.

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159+,

for frequency conversion by semiconductor converter.

11	.. By electron tube converter:

This subclass is indented under subclass 9. Subject matter wherein the converter means includes an electron tube device.

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151,	for phase conversion by electron tube converter.
166,	for frequency conversion by electron tube converter.

12	.. By saturable reactor converter:

This subclass is indented under subclass 9. Subject matter wherein the converter means includes a saturable reactor device.

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91+,	for current conversion with saturable reactor control means in the line current.

13	CURRENT CONVERSION:

This subclass is indented under the class definition. Subject matter wherein the conversion system includes means to convert alternating current to direct current or direct current to alternating current.

(1) Note. The conversion systems included in this and the indented subclasses are the current conversion systems as defined in the class definition.

(2) Note. In the communication arts, there are many different conversion systems which are, in fact, converters of D.C. to A.C. or vice versa. A partial list of such converters includes oscillators, detectors, amplifiers, demodulators, etc. See the class definition, Lines With Other Classes, for more detailed discussion of the conversion systems not included in this class. See the class definition, References to Other Classes, for a listing of the related art.

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1+,	for current conversion systems cascaded or combined with frequency or phase converters without intermediate conversion to D.C.

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331,	Oscillators, appropriate subclasses for self-sustaining electric wave generating systems for converting direct current to alternating current.
378,	X-Ray or Gamma Ray Systems or Devices, subclasses 101+ for X-ray tube energizing circuits which may include circuit interrupter type converters.

This subclass is indented under subclass 13. Subject matter wherein the conversion system is operated at temperatures near absolute zero.

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141,	for current conversion systems with noncryogenic cooling means.

15	. Including D.C.-A.C.-D.C. converter:

This subclass is indented under subclass 13. Subject matter including a means for changing a source of direct current to an intermediate alternating current (i.e., inverter), and an additional means for changing said intermediate alternating current to a direct-current output (i.e., rectifier).

(1) Note. Chopper-type converters are classified in this or indented subclasses.

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52+,	67+, 76+, 81+, 84+, 108+, 114+, and 125+, for single stage A.C.-D.C. systems.
55+,	71+, 95+, 109, 120+, 131+, and 135+, for single stage D.C.-A.C. systems.

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324,	Electricity: Measuring and Testing, subclass 118 for amplifiers of the type described below under Class 330, when claimed in combination with a meter.
330,	Amplifiers, subclass 10 for amplifier systems for D.C. amplification which have a modulator means to convert D.C. to A.C., and A.C. amplifier and demodulator means to detect the D.C. signal for feeding to the load. See the search notes thereunder.

16	.. Having transistorized inverter:

This subclass is indented under subclass 15. Subject matter wherein the inverter includes a switch means for interrupting, at regular intervals, current supplied from said source of direct current, and further wherein said switch means comprises an active, three-electrode semiconductor (i.e., transistor).

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27,	for a D.C.-A.C.-D.C. converter wherein the switch means is a thyristor (e.g., SCR, etc.).
29,	for a D.C.-A.C.-D.C. converter wherein the switch means is an electron tube.
32,	for a D.C.-A.C.-D.C. converter wherein switch means is a rotary commutator.
33,	for a D.C.-A.C.-D.C. converter wherein the switch means is a vibrator-type inverter.
80,	97-98 and 131, for single stage D.C.- A.C. conversion by transistorized inverter means.

17	... Bridge type:

This subclass is indented under subclass 16. Subject matter in which the inverter consists of either two transistors and two capacitors or four transistors in a bridge configuration.

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98,	for transistorized bridge-type conversion means with transistor control means in the line circuit.
132,	for single stage D.C.-A.C. conversion by transistorized bridge-type conversion means.

18	... Single ended self-oscillating type:

This subclass is indented under subclass 16. Subject matter in which one transistor switch means automatically operates to consecutively and periodically couple the source to an inductive device.

(1) Note. The inductive device may be a swinging choke or the primary winding of a power transformer.

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20,	for single ended separately driven type.
30,	for single ended electron tube type.

19	.... With automatic control of the magnitude of the voltage or current:

This subclass is indented under subclass 18. Subject matter which includes circuitry for the regulation of the output voltage or current.

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21,	23, 25+, 28, and 78+, for other automatic voltage and current regulation circuits.

20	... Single ended separately driven type:

This subclass is indented under subclass 16. Subject matter wherein the inverter further includes an inductive device (e.g., transformer winding, etc.) connected to receive source current conducted by said transistor switch means, and switch control means for controlling conduction and non-conduction of said transistor switch means (i.e., at said regular intervals) in a manner that passes conducted current through said inductive device in only one direction.

(1) Note. The inductive device may be a swinging choke or the primary winding of a power transformer.

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18,	for single ended self-oscillating type transistorized inverters.
30,	for single ended tube type transistorized inverters.

21.01

.... With automatic control of the magnitude of output voltage or current:

	This subclass is indented under subclass 20. Subject matter further including means responsive to a circuit condition (e.g., via feedback, etc.) for regulating the amplitude of rectifier output voltage or current.

21.02

..... For resonant-type converter:

This subclass is indented under subclass 21.01. Subject matter wherein the inverter includes an LC tank circuit coupled to receive D.C. source current conducted through said transistor switching means.

(1) Note. The inductive device (e.g., transformer winding, etc.) of the inverter is commonly coupled with a capacitor to form the LC tank circuit, whereby action of the transistor switching means is utilized to pump energy into the tank circuit.

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18,	for a converter that includes a single-ended transistor inverter of the self-oscillating type.
21.04,	for a forward-type converter that includes a single-ended, separately-driven transistor inverter.
21.12,	for a flyback-type converter that includes a single-ended, separately-driven transistor inverter.

21.03

...... Having particular zero-switching control circuit (e.g., for quasi-resonant converter, etc.):

	This subclass is indented under subclass 21.02. Subject matter wherein the switching control means includes detailed means for causing the transistor switch means to change its state of conduction at, or substantially close to, the lowest magnitude of voltage across, or current through, the transistor switch means.

21.04

..... For forward-type converter:

This subclass is indented under subclass 21.01. Subject matter wherein the means for changing intermediate alternating current to a direct-current output is constructed and arranged, with respect to the inductive device of the inverter, to output direct-current when the transistor switch means is conductive.

(1) Note. The means for changing intermediate alternating current to a direct-current output is commonly a rectifier coupled to a secondary winding of a transformer (where the primary winding constitutes the inductive device of the inverter), and the rectifier is oriented with respect to the "dot" convention of the transformer to allow current to flow through the secondary (and rectifier) via induction, due to primary current, when the transistor switch means is turned on (in contrast to a flyback-type converter, wherein energy stored in the during primary conduction of the transistor switching means is inductively coupled to the secondary during primary-field decay when the transistor switch means is turned off).

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21.02,	for a resonant-type converter that includes a single-ended, separately-driven transistor inverter.
21.12,	for a flyback-type converter that includes a single-ended, separately-driven transistor inverter.

21.05

...... Having digital logic:

This subclass is indented under subclass 21.04. Subject matter wherein the switch control means includes means to process coded data that is in a discrete, discontinuous (i.e., digital) form.

(1) Note: Implicit in the above definition is the requirement that the data be processed via an instruction set in some manner -- e.g., manipulated, converted, etc. -- while in the digital domain, either by hardware or software or both, as opposed to mere threshold detection of amplitude level (e.g., a mere latch, etc.).

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1.13,

for utilization of digital logic in the swich control means of a flyback-type converter.

21.06

...... Having synchronous rectifier:

This subclass is indented under subclass 21.04. Subject matter wherein the means for changing the intermediate alternating current to a direct-current output (i.e., rectifier) includes a switchable element (e.g., MOSFET, etc.), and means for controlling conduction of said switchable element in functional relation to the switching of the inverter"s transistor switch means.

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21.14,

for synchronous rectification in a flyback-type converter.

21.07

...... Having feedback isolation (e.g., opto-isolator, transformer coupled, etc.):

This subclass is indented under subclass 21.04. Subject matter further including means for obtaining a signal indicative of a condition under the control of the means for regulating (i.e., feedback signal), and means for communicating said signal to the means for regulating, wherein said means for communicating includes means for preventing direct electrical (i.e., ohmic) conduction between said means for obtaining and said means for regulating.

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21.15,

for use of feedback isolation in a flyback-type converter.

21.08

...... Having feedback winding inductively coupled to inverter inductive device (e.g., tertiary winding, etc.):

This subclass is indented under subclass 21.04. Subject matter further including an electrical coil means (i.e., feedback winding) wound around a magnetic circuit portion of the inductive device of the inverter for outputting a signal to the means for regulating, and further wherein said feedback winding is separate and distinct from any winding that carries load current.

(1) Note. The feedback winding is commonly wound on a portion of a magnetic core shared by the inductor of the inverter, where the inductor is commonly the primary winding of a transformer.

(2) Note. The signal from the feedback winding is commonly utilized to indicate load current. [However, see (3)Note.]

(3) Note. When a feedback signal is obtained from a winding that supplies load current, the winding is not considered to be a feedback winding for this subclass.

(4) Note. The use of a winding to obtain a feedback signal is to be distinguished from a winding (e.g., transformer, etc) utilized to conductively isolate an "obtained" feedback signal from, for example, the means for regulating.

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21.07,	for a transformer utilized for feedback isolation in a forward-type converter.
21.09,	for a feedback winding coupled to a circuit portion other than the inductor for detecting output current in a forward-type converter.
21.15,	for a transformer utilized for feedback isolation in a flyback-type converter.
21.17,	for a feedback winding, coupled to a circuit portion other than the inductor, for detecting output current in a flyback-type converter.

21.09

...... Having output current feedback:

This subclass is indented under subclass 21.04. Subject matter further including means for obtaining a signal indicative of rectifier output current, and means for presenting said signal to the means for regulating.

(1) Note. A voltage obtained from a current-sensing resistor is a signal indicative of current proper for this subclass.

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21.17,

for use of output current feedback in a flyback-type converter.

21.1	...... Utilizing pulse-width modulation:

This subclass is indented under subclass 21.04. Subject matter wherein the switch control means includes means to vary the conduction/non-conduction duty cycle of the transistor switch means to control the rectifier output current or voltage.

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21.18,

for use of pulse-width modulation to regulate the output current or voltage of a flyback-type converter.

21.11

....... Having particular pulse-width modulation circuit:

	This subclass is indented under subclass 21.1. Subject matter including detailed means for performing the pulse-width modulation.

21.12

..... For flyback-type converter:

This subclass is indented under subclass 21.01. Subject matter wherein energy from the source of direct current is stored in the inductive device of the inverter when the transistor switch means is conductive, and further wherein the said means for changing intermediate alternating current to a direct-current output (i.e., rectifier) includes means for converting the stored energy to a direct-current output when the transistor switch means is non-conductive.

(1) Note. The means for changing intermediate alternating current to a direct-current output is commonly a rectifier coupled to a secondary winding of a transformer (where the primary winding constitutes the inductive device of the inverter), and the rectifier is oriented with respect to the "dot" convention of the transformer to allow current to flow through the secondary winding (and rectifier) via induction, due to primary-field decay, when the transistor switch means is turned off (in contrast to a forward-type converter, where primary current is inductively coupled to the secondary when the transistor switching means is turned on).

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21.02,	for a resonant-type converter that includes a single-ended, separately-driven transistor inverter.
21.04,	for a forward-type converter that includes a single-ended, separately-driven transistor inverter.

21.13

...... Having digital logic:

This subclass is indented under subclass 21.12. Subject matter wherein the switch control means includes means to process coded data that is in a discrete, discontinuous (i.e., digital) form.

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21.05,

for utilization of digital logic in the swich control means of a forward-type converter.

21.14

...... Having synchronous rectifier:

This subclass is indented under subclass 21.12. Subject matter wherein the means for changing the intermediate alternating current to a direct-current output (i.e., rectifier) includes a switchable element (e.g., MOSFET, etc.), and means for controlling conduction of said switchable element in functional relation to the switching of the inverter"s transistor switch means.

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21.06,

for synchronous rectification in a forward-type converter.

21.15

...... Having feedback isolation (e.g., opto-isolator, transformer coupled, etc.):

This subclass is indented under subclass 21.12. Subject matter further including means for obtaining a signal indicative of a condition under the control of the means for regulating, and means for communicating said signal to the means for regulating, wherein said means for communicating includes means for preventing direct electrical (i.e., ohmic) conduction between said means for obtaining and said means for regulating.

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21.07,

for use of feedback isolation in a forward-type converter.

21.16

...... Having feedback winding inductively coupled to inverter inductive device (e.g., tertiary winding, etc.):

This subclass is indented under subclass 21.12. Subject matter further including an electrical coil means (i.e., feedback winding) wound around a magnetic circuit portion of the inductive device of the inverter for outputting a signal to the means for regulating, and further wherein said feedback winding is separate and distinct from any winding that carries load current.

(1) Note. The feedback winding is commonly wound on a portion of a magnetic core shared by the inductor of the inverter, where the inductor is commonly the primary winding of a transformer.

(2) Note. The signal from the feedback winding is commonly utilized to indicate load current. [However, see (3)Note.]

(3) Note. When a feedback signal is obtained from a winding that supplies load current, the winding is not considered to be a feedback winding for this subclass.

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21.07,	for a transformer utilized for feedback isolation in a forward-type converter.
21.09,	for a feedback winding, coupled to a circuit portion other than the inductor, for detecting output current in a forward-type converter.
21.15,	for a transformer utilized for feedback isolation in a flyback-type converter.
21.17,	for a feedback winding coupled to a circuit portion other than the inductor for detecting output current in a flyback-type converter.

21.17

...... Having output current feedback:

This subclass is indented under subclass 21.12. Subject matter further including means for obtaining a signal indicative of rectifier output current, and means for presenting said signal to the means for regulating.

(1) Note. A voltage obtained from a current-sensing resistor is a signal indicative of current proper for this subclass.

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21.09,

for use of output current feedback in a forward-type converter.

21.18

...... Utilizing pulse-width modulation:

This subclass is indented under subclass 21.12. Subject matter wherein the switching control means includes means to vary the conduction/non-conduction duty cycle of the transistor switching means to control the output current or voltage.

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21.1,

for use of pulse-width modulation to regulate the output current or voltage of a forward-type converter.

22	... Double ended (i.e., push-pull) self-oscillating type:

This subclass is indented under subclass 16. Subject matter in which the inverter comprises a push-pull oscillator.

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24+,	and 134, for other double ended separately driven type.
31,	for double ended tube type inverter.

23	.... With automatic control of the magnitude of the output voltage or current:

This subclass is indented under subclass 22. Subject matter which includes circuitry for the regulation of the output voltage or current.

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19,	21.01, 25-41, and 78-102, for other automatic voltage and current regulation circuits.

24	... Double ended (i.e., push-pull) separately driven type:

This subclass is indented under subclass 16. Subject matter in which an independent drive circuit controls both the on and the off state of the transistors.

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22+,	and 133, for other transistorized double ended inverters.
31,	for tube type double ended inverters. 134, for single stage transistorized double ended separately driven type inverters.

25	.... With automatic control of the magnitude of the output voltage or current:

This subclass is indented under subclass 24. Subject matter which includes circuitry for the regulation of the output voltage or current.

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19,	21.01, 23, 28, and 78-102, for other automatic voltage and current regulation circuits.

26	..... Using pulse width modulation:

This subclass is indented under subclass 25. Subject matter wherein circuit means are included to control the duration of the pulses that drive the transistors, which regulate the magnitude of the output voltage or current.

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41+,	for pulse modulating techniques in introducing or eliminating frequency components to or from inverter systems.

27	.. Having thyristor inverter, (e.g., SCR):

This subclass is indented under subclass 15. Subject matter wherein the inverter includes a switch means for interrupting, at regular intervals, current supplied from said source of direct current, wherein said switching means comprises a bistable semiconductor means having three or more junctions (e.g., thyristor, etc.).

(1) Note. Examples of these devices are the silicon controlled rectifier (SCR), the gate controlled switch (SCS), or the four layer diode.

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96,	for inverter systems with automatic control having thyristor control means in the line circuit.
135+,	for single stage thyristor inverter systems.

28	... With automatic control of the magnitude of the output voltage or current:

This subclass is indented under subclass 27. Subject matter which includes circuitry for the regulation of the output voltage or current.

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19,	21.01, 23, 28, and 78-102, for other automatic voltage and current regulation circuits.

29	.. Having electron tube inverter:

This subclass is indented under subclass 15. Subject matter in which the D.C.-A.C. conversion is performed by circuitry utilizing electron tubes.

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38,	and 120+, for other inverters utilizing electron tubes.

30	... Single ended type:

This subclass is indented under subclass 29. Subject matter in which one electronic tube is repeatedly and periodically coupled to an inductive device.

(1) Note. The inductive device may be a swinging choke or the primary winding of a power transformer.

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18+,	for single ended transistorized self- oscillating type inverters.
20+,	for single ended transistorized separately driven type inverters.

31	... Double ended type (i.e., push-pull):

This subclass is indented under subclass 29. Subject matter in which two electronic tubes are alternately and periodically coupled to opposite terminals of a center-tapped primary winding of a power transformer.

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22+,	for double ended transistorized self- oscillating type inverters.
24+,	for double ended transistorized separately driven type inverters.

32	.. Rotary-commutator-type inverter:

This subclass is indented under subclass 15. Subject matter in which the conversion is performed mechanically utilizing rotating, arcuate segments.

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109,	for other rotary-type inverters.

33	.. Vibrator-type inverter:

This subclass is indented under subclass 15. Subject matter in which the conversion is performed by a vibrator.

(1) Note. See the class definition, Glossary, for definition of vibrator.

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110,	for other vibrator-type inverters.

34	. Including an A.C.-D.C.-A.C. converter:

This subclass is indented under subclass 13. Subject matter including a first stage with means to change alternating current to intermediate direct current, and a further second stage with means to change the intermediate direct current to alternating current.

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52+,	61, 67+, 84+, 108, 114+, and 125, for A.C. to D.C. single current conversion systems.

35	.. For transfer of power via a high voltage D.C. link (i.e., HVDC transmission system):

This subclass is indented under subclass 34. Subject matter wherein the conversion of A.C. to D.C. facilitates the transmission of power as D.C. between A.C. systems.

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51,	for HVDC transmission systems with automatic or integral protection means.

36	.. For change of phase (e.g., number of phases):

This subclass is indented under subclass 34. Subject matter wherein there is a phase conversion with an intermediate conversion to D.C.

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2+,	9+ and 148+, for phase conversion without intermediate conversion to D.C.

37	.. By semiconductor rectifier and inverter:

This subclass is indented under subclass 34. Subject matter which includes semiconductor converting elements in both this rectifier and the inverter.

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10,	16+ and 27+, for converters which both rectify and invert, and utilize semiconductor elements to perform the inverting conversion.
53+,	61, 67+, 77, and 125+, for semiconductor rectifier systems.
56.01,	131-134, and 135, for semiconductor inverter systems.

38	.. By electron tube rectifier and inverter:

This subclass is indented under subclass 34. Subject matter which includes electron tubes as the converting elements in both the rectifier and the inverter.

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27+,	for current converters which both invert and rectify having electron tube inverter.
114,	for electron tube rectifier systems.
120+,	for electron tube inverter systems.

39	. With means to introduce or eliminate frequency components:

This subclass is indented under subclass 13. Subject matter wherein the system includes means for introducing a desired harmonic frequency into the system or filtering an undesired frequency component from the system.

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307,	Electrical Transmission or Interconnection Systems, subclass 3 for systems in which currents of different frequency or phase are superimposed thereon; and subclass 73 for systems having plural supply circuits of different frequency; also, subclass 105 for systems with harmonic filters or neutralizers.
329,	Demodulators, subclasses 318+ for undesired signal removal from a frequency demodulator and subclasses 349+ for undesired signal removal from an amplitude demodulator.
332,	Modulators, appropriate subclasses for systems wherein a single wave controls a base fundamental or carrier wave to produce a resultant modulated wave.
333,	Wave Transmission Lines and Networks, subclasses 167+ for wave filter networks.

40	.. In inverter systems:

	This subclass is indented under subclass 39. Subject matter where the system is a D.C. to A.C. converter.

41	... By pulse modulation technique (e.g. PWM, PPM, etc.):

This subclass is indented under subclass 40. Subject matter wherein each half cycle of the basic inverter frequency is divided into two or more pulses in accordance with a modulating waveform.

(1) Note. The most common technique in this subclass is pulse width modulation.

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307,	Electrical Transmission or Interconnection Systems, subclasses 265+ for systems having signal shaping, converting or generating means with pulse width control.

42	.... Including notching:

	This subclass is indented under subclass 41. Subject matter wherein "Notches" are produced in the inverted waveform by temporarily applying opposite discrete voltages from that which dominates during the waveform cycle.

43	... By step-wave, amplitude summation technique:

This subclass is indented under subclass 40. Subject matter in which a plurality of square waves are selectively combined to provide stepped waveform approaching a sine wave.

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307,	Electrical Transmission or Interconnection Systems, subclass 107 for inverters with waveform or wave shape determining systems.

44	.. In rectifier systems:

	This subclass is indented under subclass 39. Subject matter wherein the systems is an A.C.-D.C. converter.

45	... Including means for reducing ripples from the output:

This subclass is indented under subclass 44. Subject matter wherein the means reduce the ripple from the output D.C. line.

(1) Note. The most usual means in this subclass is a low pass filter used to eliminate ripple from the D.C. line.

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333,	Wave Transmission Lines and Networks, subclass 181 for filters of the smoothing type, e.g., direct current power supply filters.

46	.... With ripple responsive, automatic control:

	This subclass is indented under subclass 45. Subject matter wherein the means provided are responsive to the D.C. ripple on the output line, and the means include circuitry for reducing the magnitude of the sensed ripple.

47	.... With low-pass L or LC filter:

This subclass is indented under subclass 45. Subject matter wherein a low pass inductor or inductor-capacitor filter is used to reduce the ripple.

(1) Note. The filter may be integral with or on the output side of the rectifier.

48	..... For semiconductor rectifier:

	This subclass is indented under subclass 47. Subject matter wherein the rectification is performed by a semiconductor system or device.

49	. With starting arrangement:

	This subclass is indented under subclass 13. Subject matter having means to initiate operation of the conversion system.

50	. Including automatic or integral protection means:

This subclass is indented under subclass 13. Subject matter including means which are automatically responsive to an abnormal or unsafe condition and either disables the system or corrects the abnormal or unsafe condition.

(1) Note. Examples of the conditions to which the systems of this subclass are responsive are: arc back, flash over, excess heating, short circuit, open ground, input voltage failure, failure of an element of the system, excess overload and underload.

(2) Note. The abnormal or unsafe condition may be in the converter device or in any other part of the system.

(3) Note. An example of the integral protection means is a zener diode which responds to an overload condition.

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340,	Communications: Electrical, subclasses 635+ for electrical apparatus condition responsive means.
361,	Electricity: Electrical Systems and Devices, subclasses 1+ for safety and protection of general systems and devices, subclasses 91.1+ for overvoltage protection, and 93.1+ for abnormal current protection.

51	.. For high voltage D.C. transmission systems:

This subclass is indented under subclass 50. Subject matter wherein the system for which protection is provided is a high voltage D.C. transmission system.

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35,	for other HVDC transmission systems.

52	.. For rectifiers:

	This subclass is indented under subclass 50. Subject matter wherein the systems for which protection is provided is an A.C. to D.C. converter.

53	... Semiconductor type:

	This subclass is indented under subclass 52. Subject matter which includes a semiconductor device as the converting element.

54	.... Thyristor:

This subclass is indented under subclass 53. Subject matter wherein the semiconductor device is a "Thyristor".

SEE OR SEARCH CLASS:

257,	Active Solid-State Devices (e.g., Transistors, Solid-State Diodes), subclasses 107 through 181for regenerative type devices, including thyristors.

55	.. For inverters:

	This subclass is indented under subclass 50. Subject matter wherein the system for which protection is provided is a D.C. to A.C. converter.

56.01

... Transistor inverter:

	This subclass is indented under subclass 55. Subject matter wherein said D.C. to A.C. converter includes switch means for interrupting, at regular intervals, current from the supply of said D.C., wherein said switch means comprises an active, three-electrode, semiconductor (i.e., transistor).

56.02

.... Bridge type:

This subclass is indented under subclass 56.01. Subject matter wherein said switch means includes a series-connected pair of transistors connected across said supply of D.C., and further wherein the series-connection point of the series-connected pair is the A.C. output of said converter.

(1) Note. The bridge can be a half-wave or full-wave type (one or two pairs of transistors, respectively), and commonly includes multiple pairs for multiple phases of A.C., wherein each phase is derived from the series-connection point of a separate and distinct pair of series-connected transistors.

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.06,	for protection means in a double-ended transistor inverter.
56.09,	for protection means in a single-ended transistor inverter.
56.12,	for transient protection means (e.g., snubber, etc.) in an unspecified transistor inverter.

56.03

..... Having current protection (e.g., over current, short, etc.):

This subclass is indented under subclass 56.02. Subject matter including protection from an abnormal or unsafe current condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.07,	for current protection means in a double-ended transistor inverter.
56.1,	for current protection means in a single-ended transistor inverter.
56.12,	for transient protection means (e.g., snubber, etc.) in an unspecified transistor inverter.

56.04

...... Including short protection across a series-connected pair of transistors (e.g., shoot-through protection, etc.):

	This subclass is indented under subclass 56.03. Subject matter including means for preventing simultaneous conduction of both transistors of a series-connected pair of transistors.

56.05

..... Having voltage protection:

This subclass is indented under subclass 56.02. Subject matter including protection from an abnormal or unsafe voltage condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.08,	for voltage protection means in a double-ended transistor inverter.
56.11,	for voltage protection means in a single-ended transistor inverter.
56.12,	for transient protection means (e.g., snubber, etc.) in an unspecified transistor inverter.

56.06

.... Double-ended type:

This subclass is indented under subclass 56.01. Subject matter wherein the inverter further includes an inductive device (e.g., transformer winding, etc.) having first and second opposite ends and a tap between said ends, and said transistor switch means includes means for conducting and interrupting, at regular intervals, direct current from each opposite end to said tap -- or from said tap to each end -- and further wherein said transistor switch means interrupts current through one of said opposite ends while conducting current through the opposite end, in an alternating sequence.

(1) Note. The inductor device is commonly a center-tapped winding of a transformer, which provides for balanced operation in the winding.

(2) Note. The switch means may supply either:

(a) opposite polarities of D.C. to opposite ends of the inductive device, respectively, where there is a common tap (e.g., grounded center tap, etc.); or,

(a) alternately connect one pole of D.C. to opposite ends of the inductive device, where the opposite pole of D.C. is connected to a tap.

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.02,	for protection means in a bridge-type transistor inverter.
56.09,	for protection means in a single-ended transistor inverter.
56.12,	for transient protection means (e.g., snubber, etc.) in an unspecified transistor inverter.

56.07

..... Having current protection:

This subclass is indented under subclass 56.06. Subject matter including protection from an abnormal or unsafe current condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.03,	for current protection means in a bridge-type transistor inverter.
56.1,	for current protection means in a single-ended transistor inverter.
56.12,	for transient protection means (e.g., snubber, etc.) in an unspecified transistor inverter.

56.08

..... Having voltage protection:

This subclass is indented under subclass 56.06. Subject matter including protection from an abnormal or unsafe voltage condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.05,	for voltage protection means in a bridge-type transistorized inverter.
56.11,	for voltage protection means in a single-ended transistor inverter.
56.12,	for transient protection means (e.g., snubber, etc.) in an unspecified transistor inverter.

56.09

.... Single-ended type:

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.02,	for protection means in a bridge-type transistor inverter.
56.06,	for protection means in a double-ended transistor inverter.
56.12,	for transient protection means (e.g., snubber, etc.) in an unspecified transistor inverter.

56.1	..... Having current protection:

This subclass is indented under subclass 56.09. Subject matter including protection from an abnormal or unsafe current condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.03,	for current protection means in a bridge-type transistor inverter.
56.07,	for current protection means in a double-ended transistor inverter.
56.12,	for transient protection means (e.g., snubber, etc.) in an unspecified transistor inverter.

56.11

..... Having voltage protection:

This subclass is indented under subclass 56.09. Subject matter including protection from an abnormal or unsafe voltage condition.

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.05,	for voltage protection means in a bridge-type transistor inverter.
56.08,	for voltage protection means in a double-ended transistor inverter.
56.12,	for transient protection means (e.g., snubber, etc.) in an unspecified transistor inverter.

56.12

.... Transient protection (e.g., snubber, etc.):

This subclass is indented under subclass 56.01. Subject matter including means to prevent, dissipate, or redirect excess energy from a voltage or current spike or overshoot (i.e., transient).

SEE OR SEARCH THIS CLASS, SUBCLASS:

56.02,

for transient protection means in a transistor inverter having a specified topology.

57	... Thyristor:

This subclass is indented under subclass 55. Subject matter wherein said D.C. to A.C. converter includes a switch means for interrupting current, at regular intervals, from the supply of said D.C., wherein said switch means comprises a bistable semiconductor means having three or more junctions (e.g., thyristor, etc.).

SEE OR SEARCH CLASS:

257,	Active Solid-State Devices (e.g., Transistors, Solid-State Diodes), subclasses 107 through 181for regenerative type devices, including thyristors.

	This subclass is indented under subclass 57. Subject matter wherein the inverter circuit is in a bridge-type configuration and includes at least one thyristor.

59	. With voltage multiplication means (i.e., V out > V in):

This subclass is indented under subclass 13. Subject matter wherein storage type device means are provided for multiplying the voltage, so that the output voltage is a multiple of the input voltage.

(1) Note. An example of a voltage multiplier is an arrangement wherein a plurality of condensers are charged in parallel and discharged in series.

SEE OR SEARCH CLASS:

307,	Electrical Transmission or Interconnection Systems, subclass 110 for voltage multipliers of the type which charges two or more capacitors in parallel and discharges them in series.
320,	Electricity: Battery or Capacitor Charging or Discharging, appropriate subclass for series connection of voltaic cells or capacitors in a battery or capacitor charging or discharging system.

60	.. Including semiconductor means:

	This subclass is indented under subclass 59. Subject matter wherein the converting means includes a nonlinear solid-state device.

61	... For Rectifying:

	This subclass is indented under subclass 60. Subject matter wherein the conversion is from A.C. to D.C.

62	. With voltage division by storage type impedance (i.e., V out >V in):

This subclass is indented under subclass 13. Subject matter wherein storage type device means are provided for dividing the voltage, so that the output voltage is a subdivision of the input voltage.

(1) Note. An example of a voltage divider is an arrangement wherein a plurality of capacitors are charged in series and discharged in parallel.

SEE OR SEARCH CLASS:

307,	Electrical Transmission or Interconnection Systems, subclass 109 for voltage dividers of the type which charges two or more capacitors in series and discharges them in parallel.
320,	Electricity: Battery or Capacitor Charging or Discharging, appropriate subclass for series connection of voltaic cells or capacitors in a battery or capacitor charging or discharging system.

63	. With means to selectively provide D.C. of either polarity:

	This subclass is indented under subclass 13. Subject matter having means to optionally supply a D.C. output of either a negative or positive polarity.

64	. With interphase transformer:

This subclass is indented under subclass 13. Subject matter wherein the conversion system is of a type wherein polyphase alternating current is converted to direct current or vice versa and an interphase transformer is provided in the polyphase circuit.

(1) Note. An interphase transformer is an auto transformer or a set of mutually coupled reactors used in combination with the converter transformers, where a plurality of transformers are used in the line circuits to balance the distribution of current among the converters connected to the transformer. Also, an interphase transformer may be connected to the line circuit so as to multiply the number of paths of the current through the converter without multiplying the number of phases in the line circuit containing the interphase transformers. Many of the systems having interphase transformers use electronic tubes as the converting means.

SEE OR SEARCH CLASS:

315,

Electric Lamp and Discharge Devices: Systems, subclass 142 for electronic tube systems of the gas or vapor type having a polyphase source of supply for the electronic tubes, the supply circuit including an interphase transformer. The systems in subclass 142 of Class 315 are closely analogous to the systems in this subclass as many of the systems in Class 315 are disclosed as being rectifying systems.

65	. Having plural converters for single conversion:

This subclass is indented under subclass 13. Subject matter wherein a single current conversion is effected simultaneously by a plurality of converters.

(1) Note. The converters may be connected in series, in parallel, or combinations thereof.

(2) Note. In the systems in this subclass the conversion must be only from A.C. to D.C. or from D.C. to A.C. The ordinary full wave rectifying systems are excluded because each half of the wave is rectified by a separate converter, and rectifiers are alternately effective, i.e., one half of the wave being rectified and then the other half of the wave. Full wave systems having a plurality of converters for each half of the alternating current wave are included. Likewise, polyphase systems are excluded unless one or more of the phases is provided with a plurality of converters so that a single current conversion in a phase is effected by a plurality of converters. Full wave and polyphase converter systems will be found in the other subclasses of this class.

SEE OR SEARCH THIS CLASS, SUBCLASS:

15,	and 34+, for current conversion systems where the system includes means to effect a plurality of current conversion. Examples of the systems in subclasses 34+ are systems which convert A.C. to D.C. to A.C. or which convert A.C. to D.C. to A.C. to D.C.
64,	for current conversion systems which include an interphase transformer for multiplying the number of paths through the converter without multiplying the number of phases.

66	.. Including plural anode and single cathode (e.g., vapor arc device):

This subclass is indented under subclass 65. Subject matter wherein each converter means is an electron tube device having more than one anode and only one cathode.

SEE OR SEARCH THIS CLASS, SUBCLASS:

6,	for cascaded conversion of current and phase including at least one plural anode-single cathode device.
168,	for plural anode-single cathode devices used in frequency conversion.

67	.. Plural rectifiers:

This subclass is indented under subclass 65. Subject matter having more than one rectifier as the conversion means.

SEE OR SEARCH CLASS:

257,	Active Solid-State Devices (e.g., Transistors, Solid-State Diodes), subclasses 75+ for plural discrete rectifying active solid-state devices combined with a housing.

68	... In series (e.g., series SCR"s, bridge circuits, etc.):

	This subclass is indented under subclass 67. Subject matter wherein the rectifiers are connected in series.

69	... In parallel:

	This subclass is indented under subclass 67. Subject matter wherein the rectifiers are connected in parallel.

70	.... Including semiconductor device:

	This subclass is indented under subclass 69. Subject matter wherein the converting means includes a semiconductor device.

71	.. Plural inverters:

	This subclass is indented under subclass 65. Subject matter having more than one inverter as the conversion means.

72	... Master-slave:

	This subclass is indented under subclass 71. Subject matter wherein one inverter is operated in a phase shifted relationship with respect to a second inverter.

73	. Constant current to constant voltage or vice versa:

This subclass is indented under subclass 13. Subject matter wherein the system includes means for changing constant current to constant voltage or vice versa.

(1) Note. Some exemplary arrangements for changing constant current to constant voltage or vice versa include monocyclic networks and networks and constant current transformers.

SEE OR SEARCH CLASS:

323,	Electricity: Power Supply or Regulation Systems, subclasses 220 through 354for miscellaneous current regulating systems of the constant current type.

74	. With condition responsive means to control the output voltage current:

This subclass is indented under subclass 13. Subject matter wherein the system is provided with means responsive to a predetermined condition which controls the voltage and/or current magnitude of the system in response to that condition.

(1) Note. The control may be accomplished by controlling any of the following: (1) The converter supply circuit; (2.) The converter load circuit; (3) The converter itself.

SEE OR SEARCH CLASS:

340,	Communications: Electrical, subclasses 635+ for electrical apparatus condition responsive means.

75	.. Including inductive integral sensing and control means (e.g., ferroresonant circuit):

This subclass is indented under subclass 74. Subject matter wherein the system includes inductive integral means for performing the dual functions of sensing a condition and regulating the output voltage or current.

SEE OR SEARCH THIS CLASS, SUBCLASS:

82,	for plural cooperating sensing and control means for rectifier with inductive means in the line circuit.
90,	for cooperating sensing and control means for rectifier with inductive means in the line circuit.

76	.. Including integral sensing and control means for rectifier:

This subclass is indented under subclass 74. Subject matter wherein the system is a rectifier which includes integral means for performing the dual functions of sensing a condition and regulating the output voltage or current.

SEE OR SEARCH THIS CLASS, SUBCLASS:

52+,	for integral protection means for rectifiers.

77	... With semiconductor conversion means:

	This subclass is indented under subclass 76. Subject matter wherein the rectifier is a semiconductor circuit or device.

78	.. Cooperating separate sensing and control means:

This subclass is indented under subclass 74. Subject matter wherein the system includes means to sense a condition and to operate in conjunction with a separate means to regulate the output voltage or current.

(1) Note. This subclass includes those systems wherein a line condition is compared with a standard (e.g., line voltage compared with a standard voltage cell). Such systems are considered to be responsive to a single condition.

79	... Including plural sensing or control means:

This subclass is indented under subclass 78. Subject matter which includes more than one sensing or control means to regulate the output voltage or current.

(1) Note. The above plural conditions may include conditions of the same kind, such as the voltage of the supply circuit and the voltage of the load circuit.

SEE OR SEARCH CLASS:

322,	Electricity: Single Generator Systems, subclass 19 , 20, 21, and 24+ for single generator systems, including motor-generator systems having automatic control of the generator in response to plural circuit conditions of the generator.
323,	Electricity: Power Supply or Regulation Systems, appropriate subclasses for automatic voltage and/or current control systems which are responsive to plural line circuit conditions.

80	.... With transistor as control means in line circuit:

This subclass is indented under subclass 79. Subject matter having transistor control means in the line circuit, the operation of which is controlled by condition responsive means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

89,	for similar subject matter in a rectifier system.
97,	for similar subject matter in an inverter system.

81	.... For rectifier:

This subclass is indented under subclass 79. Subject matter wherein the condition responsive system is included in an A.C.-D.C. converter.

SEE OR SEARCH THIS CLASS, SUBCLASS:

84,	for single sensing and control means for a rectifier system.

82	..... With inductive control means in the line circuit:

This subclass is indented under subclass 81. Subject matter having inductive control means in the line circuit, the operation of which is controlled by the condition responsive means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

75,	for inductive integral sensing and control means.
90,	for inductive control means in the line circuit of a rectifier system.

83	..... With electron tube or valve as control means in line circuit:

This subclass is indented under subclass 81. Subject matter wherein the line circuit control means includes an electronic tube.

(1) Note. See the class definition, Glossary, for definition of electronic tube.

SEE OR SEARCH THIS CLASS, SUBCLASS:

94,	for similar subject matter in a rectifier system.
99,	for similar subject matter in an inverter system.

SEE OR SEARCH CLASS:

315,	Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to electronic tubes of the vapor or gas type.
323,	Electricity: Power Supply or Regulation Systems, subclass 227 and 291 for current or voltage magnitude control systems where the current or voltage magnitude control means includes an electronic tube.
327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous electron tube systems not otherwise classified.

84	... For rectifier system:

	This subclass is indented under subclass 78. Subject matter wherein the system is an A.C. to D.C. converter.

85	.... With thyristor control means in the line circuit:

This subclass is indented under subclass 84. Subject matter having a thyristor in the line circuit, the operation of which is controlled by condition responsive means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

96,	for this subject matter in an inverter system.

86	..... External to rectifier (e.g., pre or post regulation):

	This subclass is indented under subclass 85. Subject matter wherein the thyristor controls the flow of current to or from the rectifier.

87	..... For plural phase to D.C. rectifier:

This subclass is indented under subclass 85. Subject matter wherein the A.C. input to the rectifier is of more than one phase.

SEE OR SEARCH THIS CLASS, SUBCLASS:

129,	for plural phase A.C. to D.C. thyristor rectifier systems.

88	..... For full wave rectifier with at least 1 three electrode device:

This subclass is indented under subclass 85. Subject matter wherein each half wave is rectified by a separate rectifier and the rectifiers are alternately operated to perform full wave rectification.

SEE OR SEARCH THIS CLASS, SUBCLASS:

67+,	for plural rectifiers for single conversion.

89	.... With transistor control means in the line circuit:

This subclass is indented under subclass 84. Subject matter having transistor control means in the line circuit, the operation of which is controlled by condition responsive means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

80,	for this subject matter with plural sensing and control means.
97,	for this subject matter in an inverter system.

90	.... With inductive control means in the line circuit:

This subclass is indented under subclass 84. Subject matter having inductive control means in the line circuit, the operation of which is controlled by condition responsive means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

75,	for inductive integral means for performing the dual functions of sensing a condition and regulating the output voltage or current.
82,	for plural sensing with inductive control means in the line circuit.

91	..... Saturable reactor (e.g., magnetic amplifier):

This subclass is indented under subclass 90. Subject matter wherein the inductive control means is a saturable reactor type device.

(1) Note. A saturable reactor is a reactor provided with a control winding which is supplied with a direct current to saturate the magnetic circuit of the reactor and thereby vary its impedance.

(2) Note. The saturable reactor may be, for example, a magnetic amplifier.

SEE OR SEARCH CLASS:

323,	Electricity: Power Supply or Regulation Systems, subclass 249 , 302, 310, and 329 for current and/or voltage magnitude control systems where the control means is a saturable transformer.

92	...... In plural phase to D.C. system:

	This subclass is indented under subclass 91. Subject matter wherein the A.C. input to the system is of more than one phase and the output from the system is D.C.

93	...... With plural control windings:

	This subclass is indented under subclass 91. Subject matter where the saturable reactor has more than one control winding.

94	.... With electron tube or valve control means in the line circuit:

This subclass is indented under subclass 84. Subject matter wherein the line circuit control means includes an electronic tube.

(1) Note. See the class definition, Glossary, for definition of Electronic Tube.

SEE OR SEARCH THIS CLASS, SUBCLASS:

83,	for this subject matter in a rectifier system having plural sensing or control means.
99,	for this subject matter in an inverter system.

SEE OR SEARCH CLASS:

315,	Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to electronic tubes of the vapor or gas type.
323,	Electricity: Power Supply or Regulation Systems, subclass 227 and 291 for current or voltage magnitude control systems where the current or voltage magnitude control means includes an electronic tube.
327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous electron tube systems not otherwise classified.

95	... For inverter:

	This subclass is indented under subclass 78. Subject matter wherein the system is a D.C. to A.C. converter.

96	.... With thyristor control means in the line circuit:

This subclass is indented under subclass 95. Subject matter having a thyristor in the line circuit, the operation of which is controlled by condition responsive means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

85,	for this subject matter in a rectifier system.

97	.... With transistor control means in the line circuit:

This subclass is indented under subclass 95. Subject matter having transistor control means in the line circuit, the operation of which is controlled by condition responsive means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

80,	for this subject matter with plural sensing or control means.
89,	for this subject matter in a rectifier system.

98	..... For bridge type inverter:

This subclass is indented under subclass 97. Subject matter wherein the conversion system includes a bridge configuration type inverter.

SEE OR SEARCH THIS CLASS, SUBCLASS:

58,	for bridge configuration type inverters with automatic or integral protection means.

99	.... With electron tube or valve control means in the line circuit:

This subclass is indented under subclass 95. Subject matter wherein the line circuit control means includes an electron tube.

SEE OR SEARCH THIS CLASS, SUBCLASS:

83,	for this subject matter in a rectifier system having plural sensing or control means.
94,	for this subject matter in a rectifier system.

100	. With manual control of the output voltage or current:

	This subclass is indented under subclass 13. Subject matter wherein control of the output voltage or current is effected by hand operated means.

101	. With auxiliary bucking or boosting EMF:

This subclass is indented under subclass 13. Subject matter wherein the system is provided with means to supply additional voltage into the system which may either aid or oppose the voltage of the system.

(1) Note. The additional voltage may be introduced into either the converter supply line or the converter load line.

SEE OR SEARCH CLASS:

307,	Electrical Transmission or Interconnection Systems, subclasses 77+ for systems in which a plurality of sources of electric current are connected in series.
322,	Electricity: Single Generator Systems, subclasses 86+ for generator systems including motor generator systems, wherein the field winding is supplied by plural sources of excitation voltage.
323,	Electricity: Power Supply or Regulation Systems, subclass 259 and 344 for bucking and/or boosting transformer systems.

102	. By dynamoelectric machine converter:

This subclass is indented under subclass 13. Subject matter wherein the converter includes a dynamoelectric machine.

(1) Note. See the Glossary for a definition of Dynamoelectric Machine.

(2) Note. The dynamoelectric machine types commonly used as current converters include motor-generator sets and rotary converters.

(3) Note. Although systems involving motor-generator sets are generally classified in Class 322, Electricity: Single Generator Systems, in systems wherein there is significant conversion from D.C. to A.C. or vice versa, classification is in this class (363). However, the generic place for systems involving motor-generator sets is in Class 322. See the class definition, Lines With Other Classes, Motor Generator Systems in Class 322, Electricity, Single Generator Systems.

(4) Note. Since many of the problems of operation and control of dynamoelectric machine converters are analogous to the problems of operation, and control of motors and generators (e.g., starting speed control, excitation control, etc.), it is noted that analogous pertinent art is classified in the motor and generator classes. See search classes below.

SEE OR SEARCH THIS CLASS, SUBCLASS:

150,	for phase conversion systems of the dynamoelectric type.
174,	for frequency conversion systems of the dynamoelectric type.

SEE OR SEARCH CLASS:

310,	Electrical Generator or Motor Structure, subclass 113 for the structure of a motor-generator set; subclasses 129+ for rotary converter structure; and subclass 160 for frequency converters of the dynamoelectric type.
318,	Electricity: Motive Power Systems, appropriate subclasses for electric motor system.
322,	Electricity: Single Generator Systems, appropriate subclasses for electric motor-driven generator systems; see subclasses 14+ where the system includes means for controlling both the motor and the generator; note particularly subclass 16 for such systems having simultaneous control of both motor and generator; see subclass 39 for electric motor-driven generator systems having motor control; and see subclasses 44+ for generator control; see (3) Note, above, for the line between Classes 322 and 363.
323,	Electricity: Power Supply or Regulation Systems, subclasses 201 through 204for control systems having a dynamoelectric machine as the control means.

103	.. Plural collector type:

This subclass is indented under subclass 102. Subject matter wherein the dynamoelectric machine is of the type which has plural sets of current collectors.

(1) Note. The usual machine of this type is a rotary converter which has a single field structure, a single armature winding and the armature winding is provided both with a commutator and slip rings, the direct current brushes cooperate with the commutator and alternating current brushes cooperating with the slip rings.

(2) Note. Closely analogous subject matter is found in Class 323, Electricity: Power Supply or Regulation Systems wherein a dynamoelectric machine having plural sets of brushes is used to control voltage magnitude. However, such dynamoelectric machine (e.g., dynamotor) is not a converter since the input and output electrical energy are the same in kind (e.g., both D.C. or both A.C.).

SEE OR SEARCH THIS CLASS, SUBCLASS:

150,	for phase conversion systems having a plural current collector type dynamoelectric machine as the converter.
174+,	for frequency conversion systems having a plural current collector type dynamoelectric machine as the converter.

SEE OR SEARCH CLASS:

323,	Electricity: Power Supply or Regulation Systems, subclasses 201 through 204for current and voltage magnitude control systems including a dynamoelectric machine having plural sets of current collectors. See (2) Note above.

104	... Having plural field windings:

This subclass is indented under subclass 103. Subject matter wherein the dynamoelectric machine is provided with plural field windings.

SEE OR SEARCH CLASS:

310,	Electrical Generator or Motor Structure, subclasses 112+ for plural, structurally united dynamoelectric machines, subclass 114 for plural rotary element dynamoelectric machines operating in different fields, subclasses 134, 141, 142, and 149 for plural collector type dynamoelectric machines having plural field windings, and subclasses 184+ for plural field winding structure.
318,	Electricity: Motive Power Systems, appropriate subclasses for motor systems wherein the motor is provided with plural field windings; particularly note, subclasses 523+ for miscellaneous motor systems wherein the motor is provided with plural field windings.
322,	Electricity: Single Generator Systems, subclasses 63+ for plural field winding generator systems.

105	... Having auxiliary motor drive:

This subclass is indented under subclass 103. Subject matter wherein the dynamoelectric machine is provided with an additional driving means.

(1) Note. The subject matter of this subclass is analogous in many ways to that of motor-generator set converters. A plural set of current collectors converter is analogous to a motor-generator set in that it may be considered to have a motor part and a generator part. The addition of another motor means results in an arrangement analogous to a motor-generator set having two motors.

SEE OR SEARCH CLASS:

322,	Electricity: Single Generator Systems, subclass 9 for systems wherein a generator is provided with plural driving means. See (1) Note, above.

106	. By circuit interrupter type:

This subclass is indented under subclass 13. Subject matter wherein the converter is a circuit interrupter which is operated synchronously with the A.C. current.

(1) Note. The circuit interrupter is a periodic switch. The usual types of switches used in the systems of this subclass are vibrating and rotary switches.

SEE OR SEARCH THIS CLASS, SUBCLASS:

177,	for frequency conversion systems having a current interrupter type converter.

SEE OR SEARCH CLASS:

200,	Electricity: Circuit Makers and Breakers, subclasses 19.01+ for the structure of periodic switches.
307,	Electrical Transmission or Interconnection Systems, subclasses 96+ for systems having an intermittent regulatory interrupter, and subclasses 112+ for miscellaneous switching systems.
335,	Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 87+ for the structure electromagnetically operated periodic switches.
361,	Electricity: Electrical Systems and Devices, subclasses 139+ for relay and electromagnet systems.
378,	X-Ray or Gamma Ray Systems or Devices, subclasses 101+ for X-Ray tube energizing circuits which may include circuit interrupter type converters.

107	.. Rotating:

This subclass is indented under subclass 106. Subject matter wherein the circuit interrupter is a rotary switch.

(1) Note. A rotary switch is a device wherein a rotary contact member coacts with stationary contacts so that as the rotary member rotates the circuit between each of the stationary contacts and the rotary contact is made and broken in a predetermined sequence.

(2) Note. A usual example of a rotary switch is a commutator.

SEE OR SEARCH CLASS:

200,	Electricity: Circuit Makers and Breakers, subclasses 19.03+ , 19.07+, 19.18+, and 36+ for the structure of rotary switch structures.
250,	Radiant Energy, subclass 401 for such conversion systems wherein the load device is an X-ray apparatus.
310,	Electrical Generator or Motor Structure, subclasses 233+ for the structure of commutators for dynamoelectric machines.

108	... Rectifier (i.e., A.C.-D.C.):

This subclass is indented under subclass 107. Subject matter wherein the converter is of the type which converts alternating current into direct current.

SEE OR SEARCH THIS CLASS, SUBCLASS:

114+,	for rectifying systems having an electron tube type converter.
125+,	for rectifying systems having a semiconductor type converter.

109	... Inverter (i.e., D.C.-A.C.):

This subclass is indented under subclass 107. Subject matter wherein the converter is of the type which converts direct current into alternating current.

SEE OR SEARCH THIS CLASS, SUBCLASS:

120+,	for inverting systems having an electronic tube type converter.
123+,	for inverting systems having a semiconductor type converter.

110	.. Vibrating:

	This subclass is indented under subclass 106. Subject matter wherein the circuit interrupter is a device which has a movable conducting member which moves between contacts for converting either D.C. to A.C. or A.C. to D.C.

111	. Using electronic tube converter:

This subclass is indented under subclass 13. Subject matter wherein the converter includes an electronic tube.

(1) Note. See the class definition, under Glossary, for the definition of an electronic tube.

(2) Note. See Lines With Other Classes, Conversion Systems Not Included in This Class, in the class definition of this class for other conversion systems using electronic tubes which are not included in this class.

SEE OR SEARCH THIS CLASS, SUBCLASS:

94,	for current conversion systems wherein an electronic tube is used for line circuit control.
151,	for phase conversion systems including an electronic tube converter.
166+,	for frequency conversion systems including an electronic tube converter.

SEE OR SEARCH CLASS:

315,	Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to electronic tubes of the gas or vapor tube type. In these systems, the output circuit may be claimed if it is claimed so broadly as to be in effect the mere completion of the circuit so that a discharge may take place. In many of the systems in Class 315, the electronic tube is an asymmetrical discharge device and operates to pass electric current in one direction only between the discharge electrodes. Merely naming the device as a rectifier will not exclude the patent from Class 315, unless some subject matter is claimed which limits the system to the conversion art. The subject matter of Class 315 is closely analogous to the subject matter of this and the indented subclasses. See the class definition, Lines With Other Classes, for a statement of the line between Classes 315 and 363.
323,	Electricity: Power Supply or Regulation Systems, subclass 227 and 291 for control systems involving an electronic tube.
327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous electron tube systems not otherwise classified.

112	.. With gap in open atmosphere:

This subclass is indented under subclass 111. Subject matter wherein the electronic tube is of the type wherein the electric space discharge takes place between electrodes which are exposed to the atmosphere.

(1) Note. This type of electronic tube is usually called a spark gap or an arc device.

SEE OR SEARCH CLASS:

313,	Electric Lamp and Discharge Devices, appropriate subclasses for the structure of spark gaps and open air arc devices.
315,	Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to electronic tubes of the type which have the gap in the open atmosphere.
331,	Oscillators, subclass 127 for oscillators using a gaseous space discharge device of the spark or open arc type, and which convert direct current to oscillatory current.

113	.. With cathode element control:

This subclass is indented under subclass 111. Subject matter wherein the control of the electronic tube involves control of the cathode element.

(1) Note. Control of the cathode-anode circuit is not control of the cathode element.

(2) Note. A usual cathode element control is the control of cathode temperature.

SEE OR SEARCH CLASS:

315,

Electric Lamp and Discharge Devices: Systems, subclasses 94+ for miscellaneous systems for supplying heating current to the cathode or cathode heater of an electronic tube. The systems in Class 315, subclasses 94+ may include the circuit necessary to also supply the anode potential if the anode supply is included in combination with the supply of the cathode current. In such systems, the electronic tube may be either a vacuum tube or a gas or vapor tube. However, if the system includes the supply of control current or potential to the discharge control means, then only the systems limited to having an electronic tube of the gas or vapor type are included, and such other systems will be found in Class 250, Radiant Energy, or in one of the classes or subclasses specified in the notes to the definition of that subclass.

327,

Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous electron tube systems which include means for controlling the cathode element. See the reference to Class 315, above.

114	.. In rectifier systems:

This subclass is indented under subclass 111. Subject matter wherein the conversion is from A.C. to D.C.

SEE OR SEARCH THIS CLASS, SUBCLASS:

38,	for electron tube rectifier used in A.C.-D.C.-A.C. conversion systems.
67+,	for plural electron tube rectifiers for single current conversion.
81+,	and 84+, for electron tube rectifying systems with condition responsive means to control the output voltage or current.
108,	for circuit interrupter type rectifying systems.
113,	for electronic tube rectifiers with cathode element control.
125+,	for rectifying systems having semiconductor type converter.

115	... With retarding or delaying control means:

This subclass is indented under subclass 114. Subject matter wherein means are provided for delaying the operation of the electronic tube converter until conditions are such that its operation is safe, feasible, or desirable.

(1) Note. An example of such delay control is where the application of cathode, anode voltage is delayed until the cathode temperature has reached its operating value.

SEE OR SEARCH CLASS:

315,

Electric Lamp and Discharge Devices: Systems, subclasses 102+ for miscellaneous systems for supplying electric current and/or potential to electronic tubes where the system includes means to supply heating current to the cathode or cathode heating circuit, and means for delaying the application of anode potential until the cathode has reached its operating potential. This subclass in Class 315 provides for vacuum tube systems as well as gas or vapor tube systems, provided that in the case of the vacuum tubes there is no control of the discharge control (e.g., grid) circuit. Systems which are not limited to having a gas or vapor type electronic tube and which include the discharge control circuit will be found in Class 327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses.

327,

Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous electron tube systems having delayed or retarded operation of the tube. See the reference to Class 315, above.

116	... With discharge control means (e.g., grid):

This subclass is indented under subclass 114. Subject matter wherein the electronic tube converter is provided with a discharge control means.

(1) Note. Examples of such discharge control means include a grid, igniter, magnetic control device, etc.

SEE OR SEARCH THIS CLASS, SUBCLASS:

94,	for current conversion systems wherein an electronic tube having discharge control means is used for line circuit control.
121+,	for inverter systems including an electronic tube converter which has a discharge control means.
151,	for phase conversion systems including an electronic tube converter which has a discharge control means.
166+,	for frequency conversion systems including an electronic tube converter which has a discharge control means.

SEE OR SEARCH CLASS:

315,

Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to an electronic tube of the gas or vapor type which has a discharge control means (e.g., grid, igniter, magnetic field). Many of the systems inherently operate to convert A.C. to D.C. and many of the tubes are referred to as rectifiers, and are therefore closely analogous to the systems in this and the indented subclass. Note, especially subclasses 137+ where the supply circuit is a polyphase alternating current supply circuit; subclasses 194+ where the system includes means to shift the phase of the current or potential applied to the discharge control means with respect to the anode-cathode current to control the tube; subclasses 248+ where the source of supply is alternating current; indented subclass 252 providing for those systems which include a plurality of discharge control type electronic tubes; indented subclasses 261+ providing for those systems where the discharge control means is an auxiliary starting electrode (e.g., igniter); indented subclass 267 providing for those systems where the discharge control means is an electromagnetic means; and indented subclasses 268+ providing for the miscellaneous alternating current supplied discharge control tube systems. For the line between Classes 315 and 363, see the class definition, Lines With Other Classes.

327,

Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous electron tube systems not otherwise classified.

117	.... D.C. bias control:

This subclass is indented under subclass 116. Subject matter wherein the control of the electronic tube includes varying the magnitude of a direct current or potential applied to the discharge control means.

(1) Note. This subclass includes those systems wherein both an A.C. component and a D.C. component are applied to the control means and those systems wherein only a D.C. is applied to the control means, provided that in each case the actual control of the conductivity of the discharge device is accomplished by varying the magnitude of the D.C. voltage.

SEE OR SEARCH THIS CLASS, SUBCLASS:

116,	for the miscellaneous systems having an electronic tube converter with a discharge control means, where the conductivity of the electronic tube is controlled by controlling the time of application of a voltage but not the magnitude of either the D.C. or A.C. applied to the discharge control means. See the reference to subclass 118, below.
118,	for the systems under subclass 116 where the phase of the alternating current or potential applied to the discharge control means is shifted with respect to the cathode-anode current to control the electronic tube.

SEE OR SEARCH CLASS:

315,

Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to an electronic tube of the gas or vapor type which has a discharge control means, (e.g., grid, igniter, magnetic field). Many of the systems inherently operate to convert A.C. to D.C. and many of the tubes are referred to as rectifiers, and are therefore closely analogous to the systems in this subclass. subclasses 261 through 264, and 267 to 275 provide for the systems where the tube is supplied with alternating current and where the tube has a discharge control means which is controlled by controlling the magnitude of the direct current and/or potential is the control circuit. Subclasses 261+ provide for those systems where the discharge control means is an auxiliary starting electrode (e.g., igniter); subclass 267 provides for those systems where the discharge control means is an electromagnetic means; and subclasses 268+ provide for the miscellaneous alternating current supplied discharge control tube systems. Note, indented subclass 270 where both alternating and direct current and/or potential are supplied to the control means. See indented subclass 272 where a rectifier and/or discharge device is connected in the circuit of discharge control means. For the line between Classes 315 and 321, see the class definition, Lines With Other Classes.

327,

Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, particularly subclasses 530+ for miscellaneous electron tube systems which include DC bias control.

118	.... Phase angle control:

This subclass is indented under subclass 116. Subject matter wherein the control of the electronic tube is accomplished by controlling the phase of an A.C. current or voltage applied to the discharge control means with respect to the cathode-anode voltage.

(1) Note. This subclass includes (1) systems wherein both an A.C. current or voltage and a D.C. current or voltage are applied to the discharge control means and (2) systems wherein one or more A.C. currents or voltages are applied to the discharge control means, provided that conductivity of the electronic tube is controlled by varying the phase of the A.C. voltage.

SEE OR SEARCH THIS CLASS, SUBCLASS:

117,	for those systems wherein the conductivity of the electronic tube is controlled by both varying the magnitude of a D.C. or voltage applied to the discharge control means and by controlling the phase of an A.C. or voltage applied to the discharge control means.

SEE OR SEARCH CLASS:

315,	Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to an electronic tube of the gas or vapor type which has a discharge control means, (e.g., grid, igniter, magnetic field). Many of the systems inherently operate to convert A.C. to D.C. and many of the tubes are referred to as rectifiers, and are therefore closely analogous to the systems in this and the indented subclass. Note, especially subclasses 194+ where the supply circuit is an alternating current supply circuit and the system includes means to shift the phase of the current or potential applied to the discharge control means with respect to the anode-cathode current to control the tube, for the line between Classes 315 and 363, see the class definition, Lines With Other Classes.
323,	Electricity: Power Supply or Regulation Systems, subclass 237 , 300, and 320 for electronic tube voltage magnitude control systems having phase control of the A.C. or voltage applied to the discharge control device of the tube.
327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 231+ for miscellaneous tube phase shift or control circuits.

119	.... Particular waveform grid excitation:

This subclass is indented under subclass 116. Subject matter wherein the control of the discharge control means involves the application thereto of a voltage having a particular waveform.

(1) Note. Particular waveform is defined as a waveform significantly different from that of a sine wave.

(2) Note. Particular waveforms include square top waves, saw tooth waves, peaked waves, etc.

SEE OR SEARCH CLASS:

307,	Electrical Transmission or Interconnection Systems, subclasses 106+ for miscellaneous wave shaping systems.
315,	Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to an electronic tube of the gas or vapor type which has a discharge control means (e.g., grid, igniter, magnetic field). Many of the systems inherently operate to convert A.C. to D.C. and many of the tubes are referred to as rectifiers, and are therefore closely analogous to the systems in this and the indented subclass. subclasses 261 through 264and 267 to 275 provide for the systems where the tube is supplied with alternating current, and where the tube has a discharge control means which is controlled by applying current or voltage of a particular waveform to the discharge control means. See subclasses 261+ for those systems where the discharge control means is an auxiliary starting electrode (e.g., igniter). Note, especially indented subclass 262 where a peaking transformer is in the auxiliary starting electrode circuit; and subclass 263 where an inductance or surge generator is included in the auxiliary electrode circuit. See subclass 267 for those systems where the discharge control means is an electromagnetic means. See subclasses 268+ for the miscellaneous alternating current supplied discharge control tube systems. Note especially indented subclass 274 where a transformer such as a peaking transformer, is included in the control circuit, and indented subclass 275 where a condenser is included in the control circuit. For the line between Classes 315 and 363, see the class definition, Lines With Other Classes.
327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 100+ for miscellaneous tube networks producing a waveform of particular shape.
333,	Wave Transmission Lines and Networks, subclass 19 for differentiating and integrating networks of the passive type, and subclass 20 for wave shaping networks in general of the passive type.

120	.. In inverter systems:

This subclass is indented under subclass 111. Subject matter wherein the conversion is from D.C. to A.C.

(1) Note. There are many conversion systems for converting D.C. to A.C. in the communications arts, (e.g., oscillators, harmonic generators, amplifiers, etc.). See the class definition, Lines With Other Classes, for a list of conversion systems excluded from this class, their classification and the lines between them and the subject matter of this class.

SEE OR SEARCH THIS CLASS, SUBCLASS:

9,	for circuit interrupter type inverter systems.
29+,	for electron tube inverter in D.C.-A.C.-D.C. systems.
38,	for electron tube inverter in A.C.-D.C.-A.C. systems.
95+,	for electron tube inverting systems with means to control the output voltage or current.
131+,	and 135+, for transistor and thyristor type inverter systems.

SEE OR SEARCH CLASS:

315,

Electric Lamp and Discharge Devices: Systems, appropriate subclasses for systems for supplying electric current to electronic tubes of the gas or vapor type. Many of these systems inherently operative to convert D.C. to A.C. and are closely analogous to the systems in this and the indented subclass. Note especially subclasses 227+ where a condenser is used to control the supply of current to the electronic tube. In many of these systems the condenser causes the current through the tube to flow periodically, similar to the current flow in a relaxation oscillator circuit. Note especially indented subclass 229 where the system includes a plurality of tubes and a commutating condenser is connected between the anodes or cathodes to cause the tubes to become conductive alternately (converts D.C. to A.C.). See subclass 235 where the electronic tube has a plurality of cathodes or anodes with a commutating condenser connected between the anodes or cathodes to cause the discharge to alternate between the plural cathodes or anodes (converts D.C. to A.C.). See the class definition, Lines With Other Classes, for the line between Classes 315 and 363.

331,

Oscillators, appropriate subclasses for self-sustaining electric wave generating systems utilizing electronic tubes which convert direct current to alternating current.

121	... With discharge control means (e.g., grid):

This subclass is indented under subclass 120. Subject matter wherein the electronic tube converter has a discharge control means.

(1) Note. Such control means may include a grid, igniter, or magnetic control means.

SEE OR SEARCH THIS CLASS, SUBCLASS:

116,	for electronic tube rectifier systems wherein the electronic tube has a discharge control means.

SEE OR SEARCH CLASS:

315,

Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to electronic tubes of the gas or vapor type where the electronic tube has a discharge control means. Many of these systems inherently operate to convert D.C. to A.C. and are closely analogous to the systems in this and the indented subclass. Note especially subclass 229 where the system includes a plurality of tubes with discharge control means a commutating condenser is connected between the anodes or cathodes to cause the tubes to become conductive alternately (converts D.C. to A.C.). See subclasses 233+, 236+, and 237+ where a condenser is connected in the supply circuit of a gas or vapor tube having a discharge control means, the condenser causing the current through the tube to flow periodically similar to the current flow in a relaxation oscillator circuit. See subclasses 233+ where the tube has an auxiliary starting electrode (e.g., igniter) as the control means; subclass 236 where the control means is a magnetic means; and subclasses 237+ where the control means is an electrostatic (e.g., grid) electrode. See subclass 235 where the electronic tube has a plurality of cathodes or anodes and a discharge control means with a commutating condenser connected between the anodes or cathodes to cause the discharge to alternate between the plural cathodes or anodes (converts D.C. to A.C.). See Lines With Other Classes, in the class definition for the line between Classes 315 and 363.

327,

Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclass 597 for miscellaneous tube circuits with grid control means.

122	.... Grid-like electrode:

This subclass is indented under subclass 121. Subject matter wherein the discharge control means is of the type which controls the flow of space current by controlling the space charge between the cathode and the anode.

(1) Note. A common designation for this type of control means is a grid. The grid is usually interposed in the discharge path between the cathode and anode.

SEE OR SEARCH THIS CLASS, SUBCLASS:

119,	for electronic tube rectifier systems wherein the electronic tube is provided with grid control means.

SEE OR SEARCH CLASS:

315,

Electric Lamp and Discharge Devices: Systems, appropriate subclasses for miscellaneous systems for supplying current to electronic tubes of the gas or vapor type which have a control grid. Many of these systems inherently operate to convert D.C. to A.C. and are closely analogous to the systems in this subclass. Note especially subclass 229 where the system includes a plurality of tubes with control grids and a commutating condenser connected between the anodes or cathodes to cause the tubes to become conductive alternately. See subclass 235 where the electronic tube has a plurality of cathodes or anodes and a control grid with a commutating condenser connected between the anodes or cathodes to cause the discharge to alternate between the plural cathodes or anodes (converts D.C. to A.C.). See subclasses 237+ where a condenser is connected in the supply circuit of a gas or vapor tube having a grid, the condenser causing the current through the tube to flow periodically similar to the current flow in a relaxation oscillator circuit. See the class definition, See Lines With Other Classes, for the line between Class 315 and Class 363.

327,

Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 597+ for miscellaneous tube circuits with grid control means.

123	. Using semiconductor-type converter:

This subclass is indented under subclass 13. Subject matter wherein the converter includes a semiconductor device.

(1) Note. See the class definition, Glossary, for the definition of semiconductor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

10,	for combined phase and frequency conversion by semiconductor device converter.
15+,	and 37, and appropriate subclasses for semiconductor type converters for either D.C.-A.C.-D.C. or A.C.-D.C.-A.C. conversion.
53+,	for semiconductor type rectifier systems including automatic or integral protection means.
56.01,	for semiconductor type inverter systems including automatic or integral protection means.
159+,	for frequency conversion by semiconductor converter.

124	.. In chopper converter systems:

This subclass is indented under subclass 123. Subject matter which includes a device used to interrupt a D.C. or low frequency A.C. source at regular intervals.

SEE OR SEARCH CLASS:

307,	Electrical Transmission or Interconnection Systems, subclass 9.1 and 10.1 for chopper type amplifiers.
330,	Amplifiers, subclass 240 for chopper type circuits utilizing semiconductors.

125	.. In rectifier systems:

This subclass is indented under subclass 123. Subject matter wherein the current conversion is from A.C. to D.C.

SEE OR SEARCH THIS CLASS, SUBCLASS:

37,	for semiconductor rectifiers in A.C.-D.C.-A.C. conversion systems.
48,	for semiconductor rectifiers with low pass L or LC filter means for reducing ripples from the output.
53+,	for semiconductor rectifiers including automatic or integral protection means.
61,	for semiconductor rectifiers with voltage multiplication means.
67+,	for plural semiconductor rectifiers for single current conversion.
77,	for semiconductor rectifiers including integral sensing and control means.
108,	for circuit interrupter rectifier systems.
114+,	for electron tube rectifier systems.

This subclass is indented under subclass 125. Subject matter wherein the semiconductor device is a two-terminal device which will conduct electricity more easily in one direction than in the other.

SEE OR SEARCH THIS CLASS, SUBCLASS:

67+,	for systems which rectify by diode strings in series or in parallel.

127	... Transistor:

This subclass is indented under subclass 125. Subject matter wherein the semiconductor device includes a transistor type element.

SEE OR SEARCH THIS CLASS, SUBCLASS:

131+,

for transistor inverter systems.

128	... Thyristor:

This subclass is indented under subclass 125. Subject matter wherein the semiconductor device is of the thyristor type.

SEE OR SEARCH THIS CLASS, SUBCLASS:

54,	for thyristor rectifier systems including automatic or integral protection means.
67+,	for systems which rectify by thyristor strings in series or in parallel.
88,	for full wave rectifier with at least 1 three electrode device having thyristor control means in the line circuit.
135+,	for thyristor inverter systems.
160+,	for thyristor frequency conversion systems.

129	.... Plural phase to D.C.:

This subclass is indented under subclass 128. Subject matter wherein the A.C. input to the rectifier is of more than one phase.

SEE OR SEARCH THIS CLASS, SUBCLASS:

4,	for thyristor plural phase to D.C. converters in single phase to plural phase to D.C. systems.
87,	for plural phase to D.C. conversion with thyristor control means in the line circuit.
92,	for plural phase to D.C. conversion with saturable reactor control means in the line circuit.

130	.... With magnetic control means:

	This subclass is indented under subclass 128. Subject matter wherein the thyristor type device is regulated by magnetic means.

131	.. In transistor inverter systems:

This subclass is indented under subclass 123. Subject matter wherein the semiconductor device includes a transistor type element.

SEE OR SEARCH THIS CLASS, SUBCLASS:

16+,	for transistorized inverters in D.C.-A.C.-D.C. conversion systems.
80,	and 97+, for inverters with transistor control means in the line circuit.
127,	for transistor rectifier systems.

132	... Bridge type:

This subclass is indented under subclass 131. Subject matter wherein the inverter includes one or more transistors in a bridge configuration.

(1) Note. A bridge configuration in this art is a four terminal network with the supply being connected to two terminals opposite each other, and the load connected to the remaining terminals. One of the load terminals may be a center tap of the supply.

SEE OR SEARCH THIS CLASS, SUBCLASS:

17,	for transistorized bridge type inverters in D.C.-A.C.-D.C. conversion systems.
98,	for bridge type inverter with transistor control means in the line circuit.

133	... Double-ended (i.e., push-pull) type:

This subclass is indented under subclass 131. Subject matter wherein the inverter includes two transistors which alternately and periodically couple the source to opposite terminals of a center-tapped primary winding of a power transformer.

SEE OR SEARCH THIS CLASS, SUBCLASS:

22+,	and 24+, for transistorized double-ended inverters in D.C.-A.C.-D.C. conversion systems.

134	.... Separately driven:

This subclass is indented under subclass 133. Subject matter in which an independent drive circuit controls both the on and the off state of the transistors.

SEE OR SEARCH THIS CLASS, SUBCLASS:

24+,	for transistorized double-ended separately driven inverters in D.C.-A.C.- D.C. conversion systems.

135	.. In thyristor inverter systems:

This subclass is indented under subclass 123. Subject matter wherein the semiconductor device includes a thyristor type element.

SEE OR SEARCH THIS CLASS, SUBCLASS:

27+,	for thyristor inverters in D.C.-A.C.- D.C. conversion systems.
57+,	for thyristor inverters with automatic or integral protection means.
96,	for inverters with thyristor control means in the line circuit.
128+,	for thyristor rectifier systems.

136	... Bridge type:

This subclass is indented under subclass 135. Subject matter combined with a small box for containing Toilet Articles.

(1) Note. This subclass includes portable collapsible or hand-carried cases as distinguished form the dressing table furniture type of subclass 128 above. This subclass also includes mirrored purses or bags.

SEE OR SEARCH THIS CLASS, SUBCLASS:

128+,	for dressing table-type mirrored vanities without a carrying handle.
154+,	for illuminated containers without a mirror.

SEE OR SEARCH CLASS:

132,	Toilet, subclass 83 for a powder box and applicator with a mirror.

137	.... D.C. to plural phase A.C.:

	This subclass is indented under subclass 136. Subject matter wherein the conversion is from D.C. to plural phase A.C.

138	..... With commutation means:

	This subclass is indented under subclass 137. Subject matter having means to alternately and repeatedly turn on or off current flowing in one or more arms of the bridge inverter circuit.

139	... Double-ended (i.e., push-pull) type:

	This subclass is indented under subclass 135. Subject matter wherein the inverter includes two thyristors which alternately and periodically couple the source to opposite terminals of a center-tapped primary winding of a power transformer.

140	. Using impedance-type converter:

This subclass is indented under subclass 13. Subject matter wherein the converter includes an impedance.

(1) Note. See the class definition, under Glossary, for a definition of impedance.

SEE OR SEARCH THIS CLASS, SUBCLASS:

62,	for voltage division by storage-type impedance.
156,	for phase conversion by passive phase shift elements.
158,	for frequency conversion by varactor-type devices.

141	. With cooling means:

This subclass is indented under subclass 13. Subject matter wherein means are provided for removing heat from the conversion system.

SEE OR SEARCH THIS CLASS, SUBCLASS:

14,	for current conversion systems operating at temperatures near absolute zero.

142	. With means to connect the input to diverse power sources:

	This subclass is indented under subclass 13. Subject matter having means to optionally connect power sources of differing electrical characteristics to the input of the converter system.

143	.. 110/220 Volts A.C. in constant 110 Volts D.C. out:

	This subclass is indented under subclass 142. Subject matter wherein the power sources are 110V A.C. and 220V A.C. and the converter system output is 110V D.C.

144	. With conductive support mounting:

	This subclass is indented under subclass 13. Subject matter having a structure which holds the converter means and which is capable of transmitting electricity.

145	.. Adapted for use with alternators:

	This subclass is indented under subclass 144. Subject matter wherein the conductive support is designed to be utilized with an alternator.

146	. Encased in plug housing:

	This subclass is indented under subclass 13. Subject matter wherein the converter system in enclosed within a structure which has socket prongs or receptacles.

147	. Integrated circuit:

	This subclass is indented under subclass 13. Subject matter wherein the conversion means is composed of a combination of interconnected circuit elements inseparably associated on or within a continuous substrate.

148	PHASE CONVERSION (0₁ - 0₂) WITHOUT INTERMEDIATE CONVERSION TO D.C.:

This subclass is indented under the class definition. Subject matter wherein a system is provided which converts A.C. having one number of phases into A.C. having a different number of phases without intermediate conversion to D.C.

(1) Note. The output number of phases may be either greater or less than the input number of phases.

(2) Note. This class does not take those systems wherein a plurality of different single phase sources are combined to produce a polyphase output or wherein one or more single phase loads are connected to a polyphase source line.

SEE OR SEARCH THIS CLASS, SUBCLASS:

2+,	where the system includes means for effecting phase conversion, and also a single current conversion.
9+,	where the system includes means for effecting both phase and frequency conversions.
36,	where the system includes means for effecting phase conversion, and also plural current conversion.

SEE OR SEARCH CLASS:

307,	Electrical Transmission or Interconnection Systems, subclasses 13+ for plural load circuits connected to a polyphase system; subclasses 43+ for systems interconnecting a plurality of supply circuits; but particularly subclasses 72+ for supplies having unlike electrical characteristics; and subclass 79 for current sources interconnected in series but out of phase with each other.
310,	Electrical Generator or Motor Structure, subclass 160 for dynamoelectric frequency converter structure.
315,	Electric Lamp and Discharge Devices: Systems, subclasses 138+ for electric systems for supplying alternating current to an electric lamp or gas or vapor type electronic tube where the system includes a phase converting means in the supply circuit. Subclass 138 provides for those systems where single phase current is converted to polyphase current.
329,	Demodulators, subclasses 315+ for frequency demodulators and subclasses 345+ for phase demodulators.
331,	Oscillators, subclass 45 for self-sustaining oscillator systems provided with plural output circuits, each output producing a wave of the same frequency, the waves being displaced in phase by a fixed angle (other than phase coincidence or phase opposition) so as to produce a polyphase set of currents or voltages.

149	. With automatic voltage magnitude or phase angle control:

This subclass is indented under subclass 148. Subject matter wherein the system is provided with automatic current or voltage magnitude or automatic phase angle controls.

(1) Note. Phase angle control includes power factor control.

SEE OR SEARCH THIS CLASS, SUBCLASS:

74+,	for automatic current or voltage magnitude control means.

SEE OR SEARCH CLASS:

323,	Electricity: Power Supply or Regulation Systems, subclasses 212 through 303for automatic phase and voltage regulators.

150	. By dynamoelectric machine converter:

This subclass is indented under subclass 148. Subject matter wherein the converter includes a dynamoelectric machine.

(1) Note. See the class definition, Glossary, for a definition of dynamoelectric machine.

(2) Note. The dynamoelectric machine types commonly used as phase converters include motor-generator sets and practically every kind of A.C. motor and generator.

(3) Note. Although systems involving motor-generator sets are generally classified in Class 322, Electricity: Single Generator Systems, systems involving significant phase conversion are classified in this class (363). However, the generic place for motor-generator set systems are in Class 323. See the class definition, See Lines With Other Classes, Motor Generator Systems in Class 322, Electricity, Single Generator Systems:.

(4) Note. Since many of the problems of operation and control of dynamoelectric machine converters are analogous to the problems of operation and control of motors and generators (e.g., starting, speed control, excitation control, etc.) it is noted that analogous pertinent art is classified in the motor and generator classes.

SEE OR SEARCH THIS CLASS, SUBCLASS:

102+,	for current conversion system having a dynamoelectric machine converter.
174+,	for frequency conversion systems having a dynamoelectric machine converter.

SEE OR SEARCH CLASS:

310,	Electrical Generator or Motor Structure, subclasses 10+ for miscellaneous dynamoelectric machine structures, and subclass 161 for phase shifter dynamoelectric machines.
318,	Electricity: Motive Power Systems, appropriate subclasses for electric motor systems.
322,	Electricity: Single Generator Systems, appropriate subclasses for electric generator systems; particularly subclass 16 for motor-generator set systems having simultaneous control of both motor and generator; subclass 39 for motor- generator set systems having motor control. See (3) Note above.
323,	Electricity: Power Supply or Regulation Systems, subclasses 201 through 204for control systems involving dynamoelectric machines.

151	. By electron tube converter:

This subclass is indented under subclass 148. Subject matter wherein the converter includes an electronic tube.

(1) Note. See the class definition, Glossary for a definition of an electronic tube.

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111+,	for current conversion systems having an electronic tube converter.
166+,	for frequency conversion systems having an electronic tube-type converter.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, appropriate subclasses for miscellaneous electron tube systems not otherwise classified.

152	. By induction-type converter:

This subclass is indented under subclass 148. Subject matter wherein the conversion system includes an induction type converter.

(1) Note. The usual induction type converter is a transformer.

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170+,

for frequency conversion systems having an induction type converter.

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323,	Electricity: Power Supply or Regulation Systems, subclass 215 , 247, 301, 305, and 328 for control systems involving a transformer.
336,	Inductor Devices, appropriate subclasses for the structure of electric transformers, per se.

153	.. Transformer type:

	This subclass is indented under subclass 152. Subject matter wherein the induction type converter is a transformer.

154	... Stationary:

	This subclass is indented under subclass 153. Subject matter wherein the transformer has no moving parts.

155	.... With passive phase shift element:

This subclass is indented under subclass 154. Subject matter wherein the transformer converter system includes resistive, capacitive, or inductive elements for phase shifting.

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156,	for phase conversion by passive phase shift elements.

156	. By passive phase shift elements:

This subclass is indented under subclass 148. Subject matter wherein the phase conversion means includes resistive, capacitive, or inductive elements for phase shifting.

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155,	for stationary transformer phase conversion with passive phase shift elements.

157	FREQUENCY CONVERSION (f₁-f₂) WITHOUT INTERMEDIATE CONVERSION TO D.C.:

This subclass is indented under the class definition. Subject matter wherein an input alternating current having a first value of frequency is converted directly into an output alternating current having a second value of frequency.

(1) Note. The output frequency may be either greater or less than the input frequency.

(2) Note. See the classes referred to in the class definition, under References To Other Classes, for analogous conversion systems in the communication arts.

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8,	for the systems wherein an alternating current of a first frequency is converted to an alternating current of a second frequency and then converted to direct current or vice versa (e.g., f₁-f₂-D.C. or D.C.-f₁-f₂).
9,	for those systems wherein an input alternating current having a first frequency and a first number of phases is converted into an output alternating current having a second frequency and a second number of phases.
37,	and 38, for the systems wherein an alternating current of a first frequency is rectified and the resulting direct current is derectified and converted into an alternating current of a second frequency (e.g., f₁-D.C.-f₂).

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322,	Electricity: Single Generator Systems, subclasses 14+ for generator systems wherein the output frequency may be controlled by combined control of generator and driving means; subclasses 29+ for automatic control of generator or driving means responsive to generator frequency; and subclasses 38+ for systems wherein the output frequency may be controlled by controlling the generator driving means.
329,	Demodulators, subclasses 315+ for frequency demodulators and subclasses 345+ for phase demodulators.
331,	Oscillators, appropriate subclasses for oscillator systems having an output frequency which is a beat frequency or a function of a control frequency; see particularly subclasses 37+ for beat frequency systems wherein two sources of different frequencies are combined in a nonlinear device to produce a difference (sometimes sum) frequency; subclass 47 for plural oscillator systems wherein one oscillator varies the frequency of another; subclass 51 for cascaded oscillators of the frequency dividing type; subclass 53 for cascaded oscillators of the frequency multiplying type; subclasses 76 and 77 for oscillators combined with a particular harmonic producing or selecting network; subclasses 128 and 165+ for shock-excited resonant systems; and subclasses 145, 149, 153, and 172+ for oscillator systems of the electrically pulsed type.

158	. By varactor:

This subclass is indented under subclass 157. Subject matter wherein a two-terminal solid-state device which utilizes the voltage variable capacitance of a PN junction is included in the conversion systems.

(1) Note. A varactor is also called a varactor diode, silicon capacitor, voltage-controlled capacitor, or voltage-variable capacitor.

159	. By semiconductor converter:

This subclass is indented under subclass 157. Subject matter wherein the converter includes a semiconductor device.

(1) Note. See the class definition, Glossary, for the definition of semiconductor.

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10,	for combined phase and frequency conversion by semiconductor device converter.
37,	for systems wherein an A.C. of a first frequency is rectified and the resulting D.C. is inverted into an A.C. of a second frequency by semiconductor rectifying and inverting means.
123+,	for current conversion by semiconductor type conversion means.

160	.. Thyristor type:

This subclass is indented under subclass 159. Subject matter wherein the semiconductor device is of the thyristor type.

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257,	Active Solid-State Devices (e.g., Transistors, Solid-State Diodes), subclasses 107 through 181for regenerative type devices, including thyristors.

161	... Positive and negative groups:

This subclass is indented under subclass 160. Subject matter wherein thyristor type elements are combined in a circuit to form at least two groups, one of which operates during the positive half cycle of an A.C. input and the other during the negative half cycle.

(1) Note. A group may consist of a number of thyristor type elements connected in some well-known rectifier configuration, the output current from a group being able to flow in only one direction.

162	.... Including blanking or inhibiting means:

	This subclass is indented under subclass 161. Subject matter including means for rendering noneffective a channel or controlling device for a desired interval.

163	.. Transistor type:

	This subclass is indented under subclass 159. Subject matter where the semiconductor device is of the transistor type.

164	. With automatic voltage magnitude control:

This subclass is indented under subclass 157. Subject matter wherein the frequency conversion system includes cooperating separate sensing and control means for regulating the magnitude of the output voltage.

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165,	for frequency conversion with automatic frequency control.

165	. With automatic frequency control:

This subclass is indented under subclass 157. Subject matter wherein means responsive to a predetermined condition acts upon the system to provide a control to maintain or vary the output frequency of the system in response to that condition.

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164,	for frequency conversion with automatic voltage magnitude control.

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322,	Electricity: Single Generator Systems, subclasses 17+ for miscellaneous generator systems having automatic control of generator or driving means, which control may be control of the output frequency.
331,	Oscillators, subclasses 1+ for oscillation generation systems with automatic frequency stabilization.

166	. By electron tube converter:

This subclass is indented under subclass 157. Subject matter wherein the converter includes an electronic tube.

(1) Note. See the class definition, Glossary, for a definition of an electronic tube.

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11,	for combined phase and frequency conversion by electron tube converter.
38,	for systems wherein an A.C. of a first frequency is rectified and the resulting D.C. is inverted into an A.C. of a second frequency by electron tube rectifying and inverting means.
111+,	for current conversion systems having an electronic tube type converter.
151,	for phase conversion systems where the converter includes an electronic tube.

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84,	Music, subclasses 674+ for electronic tube musical tone generators which may include frequency converters as subcombinations thereof.
327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 113+ for miscellaneous repetition rate or frequency control or conversion.
329,	Demodulators, particularly subclass 368 and 370 for an electron discharge demodulator device in an amplitude demodulator.
331,	Oscillators, subclass 53 for cascaded oscillator systems of the frequency multiplying type, and subclasses 76 and 77 for oscillators combined with output coupling networks of the harmonic producing or selecting type. See the class definition of this class, Lines With Other Classes and Within This Class, for the line between Class 363 and Class 331, subclasses 53, 76, 77, and Class 328.

167	.. With discharge control means:

This subclass is indented under subclass 166. Subject matter wherein the electronic tube is provided with discharge control means.

(1) Note. The discharge control means may include a grid, igniter, magnetic element, etc.

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323,	Electricity: Power Supply or Regulation Systems, subclass 227 and 291 for current or voltage magnitude control systems having an electronic tube as the control means, wherein the electronic tube is provided with discharge control means.

168	... Including plural anodes and single cathode device (e.g. vapor arc device):

	This subclass is indented under subclass 167. Subject matter wherein the electronic tube is a device having more than one anode and only one cathode.

169	... Thyratron type:

	This subclass is indented under subclass 167. Subject matter wherein the electronic tube is of the thyratron type.

170	. By induction-type converter:

This subclass is indented under subclass 157. Subject matter wherein the conversion system includes an induction-type converter.

(1) Note. The usual induction-type converter is a transformer.

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152+,

for phase conversion systems having an induction converter.

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336,	Inductor Devices, appropriate subclasses for the structure of electric transformers, per se.

171	.. Transformer:

	This subclass is indented under subclass 170. Subject matter wherein the induction-type device is a transformer.

172	... Saturable core:

	This subclass is indented under subclass 171. Subject matter wherein the saturation state of the core of the induction device is controlled to regulate its operation.

173	.. LC circuit:

	This subclass is indented under subclass 170. Subject matter wherein the induction-type converter includes an LC circuit for regulating the frequency conversion.

174	.. Dynamoelectric machine:

This subclass is indented under subclass 170. Subject matter wherein the converter includes a dynamoelectric machine.

(1) Note. See the class definition, Glossary, for a definition of dynamoelectric machine.

(2) Note. Since many of the problems of operation and control of dynamoelectric machine converters are analogous to the problems of operation and control of motors and generators (e.g., starting, speed control, excitation control, etc.), it is noted that analogous pertinent art is classified in the motor and generator classes.

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102+,	for current conversion systems having a dynamoelectric converter.
150,	for phase conversion systems having a dynamoelectric converter.

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310,	Electrical Generator or Motor Structure, subclasses 10+ for miscellaneous dynamoelectric machine structure, particularly, subclass 160 for frequency converter structure.
318,	Electricity: Motive Power Systems, appropriate subclasses for electric motor systems.
322,	Electricity: Single Generator Systems, appropriate subclasses for electric generator systems.
323,	Electricity: Power Supply or Regulation Systems, subclasses 201 through 204for control systems involving dynamoelectric machines.

175	... Motor generator type:

This subclass is indented under subclass 174. Subject matter wherein the dynamoelectric machine is of the motor generator type.

(1) Note. In this arrangement the input frequency is supplied to the motor and the output frequency is taken from the generator.

(2) Note. Although systems involving motor-generator sets are generally classified in Class 322, Electricity: Single Generator Systems, systems involving significant frequency conversion are classified in this class (363). However, the generic place for systems involving motor-generator sets is in Class 322. See the class definition, Lines With Other Classes.

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102,	for current conversion systems which have a motor-generator converter.
150,	for phase conversion systems which have a motor-generator converter.

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322,	Electricity: Single Generator Systems, subclass 16 for miscellaneous motor-generator set systems having simultaneous control of both motor and generator; subclasses 17+ for motor- generator set systems having automatic control of either the motor or generator; subclass 39 for motor-generator systems having motor control.
323,	Electricity: Power Supply or Regulation Systems, subclass 202 for current or voltage magnitude control systems involving balances sets (which are motor-generator sets).

176	... Including induction motor:

This subclass is indented under subclass 174. Subject matter wherein the dynamoelectric machine is in the form of an induction motor.

(1) Note. The dynamoelectric machine does not drive any other device.

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150,	for phase conversion systems wherein the converter is in the form of an induction motor.

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310,	Electrical Generator or Motor Structure, subclasses 166+ for induction motor structure.
318,	Electricity: Motive Power Systems, subclasses 727+ for induction motor systems.

177	. By circuit interrupter converter:

This subclass is indented under subclass 157. Subject matter wherein the converter is a circuit interrupter.

(1) Note. The circuit interrupter is a periodic switch. The usual types of switches used in the systems in this subclass are vibratory and rotary switches.

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106+,

for current conversion systems having a circuit interrupter converter.

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200,	Electricity: Circuit Makers and Breakers, subclasses 19.01+ for the structure of periodic switches.
307,	Electrical Transmission or Interconnection Systems, subclasses 96+ for systems having intermittent regulatory interruption thereof, and subclasses 112+ for miscellaneous switching systems.
335,	Electricity: Magnetically Operated Switches, Magnets, and Electromagnets, subclasses 87+ for electromagnetically operated periodic switches.
361,	Electricity: Electrical Systems and Devices, subclasses 139+ for relay switching systems.

	Subject matter which includes circuitry for the regulation of the output voltage or current.

	Subject matter which includes a semiconductor device as the converting element.