*****TBD*****

This subclass is indented under the class definition. Subject matter including a dynamoelectric machine as the final control device within a power supply or regulation system.

(1) Note. This subclass does not include those systems wherein the electrical source energizes an electric motor which drives a generator whose output supplies a load circuit. This organization is considered to be an electric motor-driven generator system (see the Search Notes below)

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322,

Electricity: Single Generator Systems, see subclass 16 for electric motor-driven generator systems having combined control of the motor and generator; subclass 25 for electric generator systems wherein the generator or the generator driving means is controlled in response to the generator current and voltage; subclass 27 for electric generator systems wherein the generator or the generator driving means is controlled in response to the generator current; and subclass 39 for electric generator systems having control means for the generator driving means.

202	. Balancer sets:

This subclass is indented under subclass 201. Subject matter wherein the controlling means comprises a plurality of dynamoelectric machines electrically connected in series with their rotors mechanically connected together.

(1) Note. Such plurality of dynamoelectric machines is known in the art as a balancer set.

(2) Note. A common connection of the systems in this subclass is with the plurality of dynamoelectric machines connected in series across the source of supply and the load circuit connected across a fewer number of dynamoelectric machines.

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310,	Electrical Generator or Motor Structure, subclass 112 for plural dynamoelectric machines which are structurally united, such as in a motor generator set.

203	. With plural sets of slip rings or brushes:

This subclass is indented under subclass 201. Subject matter wherein the controlling means comprises a dynamoelectric machine having a plurality of commutators or a plurality of sets of brushes or a plurality of sets of slip rings.

(1) Note. A dynamotor (a machine which combines both motor and generator action in one magnetic field, either with two armatures or with one armature having two separate windings) is an example of a dynamoelectric machine having plural commutators.

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310,	Electrical Generator or Motor Structure, subclass 127 for plural collector type dynamoelectric machines.
322,	Electricity: Single Generator Systems, subclass 53 for single generator systems wherein the generator is of the third brush type; and subclass 92 for single generator systems wherein the generator is provided with at least two sets of brushes cooperating with a single commutator and one of the sets is short-circuited.

204	. Condition responsive:

This subclass is indented under subclass 201. Subject matter wherein the dynamoelectric machine is controlled in response to a condition of the system.

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322,	Electricity: Single Generator Systems, subclass 17 for automatic control of generator or driving means.

205	FOR REACTIVE POWER CONTROL:

This subclass is indented under the class definition. Subject matter which includes the control, elimination, or compensation for power having a difference in phase between voltage and current.

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212,	for systems which control the phase of voltage or current within one circuit with respect to the phase of voltage or current in a different circuit.

206	. Using saturable inductor:

This subclass is indented under subclass 205. Subject matter wherein the element which produces the compensation for the difference in phase is an inductor having a controllably saturable core.

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214,	for saturable inductors used in phase shift systems.
249,	for saturable transformers used in output level responsive voltage or current regulators.
302,	for saturable inductors used in input level responsive voltage or current regulators.
310,	for saturable transformers used in self-regulating systems.
329,	for saturable transformers used in external or operator controlled regulators.

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336,	Inductor Devices, appropriate subclasses for structural features of inductor devices, per se.

207	. Using converter:

This subclass is indented under subclass 205. Subject matter including an A.C. to D.C. to A.C. converter.

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363,	Electric Power Conversion Systems, subclass 34 for A.C. to D.C. to A.C. converters, per se.

208	. Using impedance:

This subclass is indented under subclass 205. Subject matter wherein the element which produces the compensation for the difference in phase is impedance (e.g., capacitive or inductive).

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218,	for impedances used in phase shift systems.
233,	293, 304, and 352, for impedances used in voltage or current regulators.

209	.. Switched impedance:

	This subclass is indented under subclass 208. Subject matter wherein the impedance is connected to the main power circuit through a switch which is controllably operable.

210	... Static switch:

	This subclass is indented under subclass 209. Subject matter where the switch is a controllable electronic tube or semiconductive device.

211	.... Digitally controlled:

Subject matter under subclasses 210 wherein the circuitry which controls the static switch contains logic elements which process a signal having discrete states.

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241,	283 and 322, for digital control of various voltage or current regulators.

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326,	Electronic Digital Logic Circuitry, appropriate subclasses for digital logic devices.

212	FOR PHASE SHIFT OR CONTROL:

This subclass is indented under the class definition. Subject matter including means to maintain a predetermined value or deviation in the value of the phase angle between the voltage or current of the output circuit with respect to a standard or with respect to the voltage or current of the input circuit.

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205,	for systems which control the phase relationship between voltage and current within the same circuit.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 141+ for phase synchronizing and subclasses 231+ for a phase shift of less than an input signal period.

213	. By splitting and combining:

	This subclass is indented under subclass 212. Subject matter including means which develop multiple phases from a single input and sums these phases in such proportion that a desired resultant phase is produced.

214	. Using saturable inductor:

This subclass is indented under subclass 212. Subject matter wherein the element which produces the shift in phase is an inductor having a controllably saturable core.

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206,	and the subclasses noted in the definition thereof for saturable inductances used in other systems.

215	. Using transformer:

This subclass is indented under subclass 212. Subject matter wherein the element which produces the shift in phase is a transformer.

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247,	305 and 328, for transformers used in voltage or current regulators.
355,	for miscellaneous transformer systems.

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336,	Inductor Devices, for transformers, per se.

216	.. With movable structure or winding:

This subclass is indented under subclass 215. Subject matter wherein the transformer includes at least one movable element, the movement thereof producing the shift in phase.

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264,	and 347, for transformers with movable elements used in voltage or current regulators.

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336,	Inductor Devices, subclasses 115 and 130 for transformers with movable elements.

217	. Using a three or more terminal semiconductive device:

This subclass is indented under subclass 212. Subject matter wherein the element which produces the shift in phase is a transistor or semiconductor controlled rectifier.

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223,	265, 311, and 349, for solid-state devices used as final control elements in voltage or current regulators.

218	. Using impedance:

This subclass is indented under subclass 212. Subject matter wherein the device which produces the shift in phase includes a capacitor, resistor, or inductor or combinations thereof.

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208,	and the subclasses noted in the definition thereof for impedances used in other systems.

219	.. In bridge:

This subclass is indented under subclass 218. Subject matter wherein the impedance is connected in a bridge circuit.

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365,	for miscellaneous impedance systems including bridge arrangements.

220	IN SHUNT WITH SOURCE OR LOAD:

This subclass is indented under the class definition. Subject matter including a final control device which is in parallel with the source circuit or the load circuit and functions to controllably divert at least part of the source"s energy away from the load.

(1) Note. Transformers which function to controllably couple a source to a load, although they may appear to be connected in shunt with the source or load, are not classified here since they do not function to divert energy.

(2) Note. Although not specifically included within each of the following definitions, shunt regulators usually include: (a) some means which produces a control signal which could be indicative of the input, output, or some condition external to the regulator, (b) some processing circuit which makes use of the control signal, and (c) a final control device which is controlled by the output of the processing circuit thus producing a controlled output of the system.

221	. Photo responsive:

This subclass is indented under subclass 220. Subject matter wherein the final control device or an element within its control circuit is responsive to light.

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902,	for optical coupling between a semiconductive device and another element.

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250,	Radiant Energy, subclasses 200 through 239for photocell systems.

222	. Using choke and switch across source:

This subclass is indented under subclass 220. Subject matter wherein an inductor is connected across a source through a switch which is intermittently operated and it is the duty cycle of the switch which determines the amount of energy which is diverted from the load.

(1) Note. The switch may take the form of mechanically operated contacts, a transistor, a SCR, a saturable reactor or other such on-off type devices.

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232,	for shunt regulators using inductors (usually saturable) as the final control device.
282,	and 351, for nonshunt switching regulators.

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363,	Electric Power Conversion Systems, subclass 15 and 124 for D.C. to A.C. to D.C. converters.

223	. Using a three or more terminal semiconductive device:

This subclass is indented under subclass 220. Subject matter wherein the final control device within the shunt circuit is a transistor or semiconductor controlled rectifier.

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265,	311 and 349, for semiconductive devices as final control devices in nonshunt regulators.

224	.. With additional series regulator:

	This subclass is indented under subclass 223. Subject matter wherein an additional stage of regulation is provided in the form of a series regulator.

225	.. Plural devices:

This subclass is indented under subclass 223. Subject matter wherein the shunt regulator is made up of more than one semiconductive device acting as the final control device.

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268,	and 350, for plural final control devices in series regulators.

226	.. Linearly acting:

This subclass is indented under subclass 223. Subject matter wherein the semiconductive device is operated within its linear range.

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273,	303 and 349, for series regulators which include linearly acting final control devices.

227	. Using electronic tube:

	This subclass is indented under subclass 220. Subject matter wherein the final control device within the shunt circuit is an electric space discharge device.

228	.. With additional series regulator:

	This subclass is indented under subclass 227. Subject matter wherein an additional stage of regulation is provided in the form of a series regulator.

229	. Using diode:

	This subclass is indented under subclass 220. Subject matter wherein the final control device within the shunt circuit is a diode.

230	.. Inverse parallel:

	This subclass is indented under subclass 229. Subject matter wherein a pair of diodes are connected in parallel but opposite directions to act as the final control device.

	This subclass is indented under subclass 229. Subject matter wherein the diode is a zener diode.

232	. Using inductor:

This subclass is indented under subclass 220. Subject matter wherein the final control device within the shunt circuit is an inductor.

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222,	for shunt regulators using an inductor and a switch across the source.
247,	305 and 328, for inductors used in nonshunt regulators.

233	. Using impedance:

This subclass is indented under subclass 220. Subject matter wherein the final control device within the shunt circuit is an impedance.

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208,	and the subclasses noted in the definition thereof for impedances used in other systems.

234	OUTPUT LEVEL RESPONSIVE:

This subclass is indented under the class definition. Subject matter which maintains an output at a desired level through the use of means which responds to deviation in the output level and produces a change in the output which is opposite to the deviation.

(1) Note. Although not specifically included within each of the following definitions, output level responsive systems usually include (a) some means which produces a signal indicative of a condition of the load which is dependent on the output level of the system or the output level of the system itself, (b) some processing circuit which makes use of the signal mentioned above, and (c) a final control device which is controlled by the output of the processing circuit thus producing a controlled output of the system.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 535+ for regulators of this type which may have a semiconductive device as the claimed load.

235	. Zero switching:

This subclass is indented under subclass 234. Subject matter wherein the input is alternating current and the final control device is a switch which is caused to change to its conductive state at or about the zero axis crossing of the input waveform.

(1) Note. Usually, the average power applied to the load is controlled by varying the number of half or full cycles of input waveform that is permitted to flow to the load.

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319,	for external or operator controlled systems of this type.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 451+ for semiconductor controlled rectifiers which are involved in zero point switching.

236	.. Nonelectrical condition sensing:

This subclass is indented under subclass 235. Subject matter wherein the means which responds to the output is a sensor which measures a nonelectrical condition (such as heat) of the system or its load, the condition being dependent upon the output of the system.

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245,	for phase controlled switching devices with nonelectrical condition sensors.

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219,	Electric Heating, subclass 482 for power supply means with nonelectrical condition sensing having a heating system as the load.

237	. Phase controlled switching using electronic tube or a three or more terminal semiconductive device:

This subclass is indented under subclass 234. Subject matter wherein the input is alternating current and the final control device is an electronic tube or three or more terminal semiconductive device which is caused to change to its conductive state at a controllable point following the zero axis crossing of the input waveform.

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300,	for input level responsive phase controlled switching systems.
320,	for external or operator controlled phase controlled switching systems.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 447+ for semiconductor controlled rectifiers which are involved in phase switching.

238	.. With soft start:

This subclass is indented under subclass 237. Subject matter wherein at the time of start up of the system, the output is gradually increased over a plurality of cycles from zero to the desired level.

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321,	for soft start of external or operator controlled systems.

239	.. Including single unidirectional element with bidirectional pass:

This subclass is indented under subclass 237. Subject matter wherein the final control device is capable of carrying current in only one direction but the circuit is arranged in such fashion that both polarities of the input are passed or controlled.

(1) Note. The unidirectional element may be a tube or semiconductive device connected within a diode bridge circuit so as to pass both polarities of the alternating current or a tube or a semiconductive device bridged by a single diode whereby one polarity of the applied A.C. is controlled and the other polarity is uncontrolled.

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324,	for external or operator controlled devices of this type.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclass 448 for A.C. gating SCR"s in a bridge.

240	.. Including saturable inductor in trigger circuit:

This subclass is indented under subclass 237. Subject matter including a signal shaping circuit between the means responsive to the output and the final control element, that signal shaping circuit including a saturable inductor.

(1) Note. The trigger circuit may be a magnetic amplifier having an output winding coupled to the control electrode of a tube or semiconductive device.

241	.. With digital control:

This subclass is indented under subclass 237. Subject matter including a signal processing circuit between the means responsive to the output and the final control device, that signal processing circuit including logic elements which process signals having discrete states.

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211,	and the subclasses noted in the definition thereof for digitally controlled systems.

242	.. Including ramp generator or controlled capacitor charging:

This subclass is indented under subclass 237. Subject matter including circuitry which produces a gradually changing signal which is ultimately proportional to the output of the device.

(1) Note. The changing signal may take the form of a sawtooth with a repeating ramp and return to an initial value. Controlled capacitor charging involves charging a capacitor to some predetermined value at which value a controllable device such as a transistor, unijunction transistor, or programmable unijunction transistor, goes into another state of conduction or exerts a controlling influence on another device.

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288,	and 326, for other systems including ramp generators or controlled capacitor charging circuits.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 131+ for a miscellaneous ramp or sawtooth waveform generator.

243	... As input to comparator:

	This subclass is indented under subclass 242. Subject matter wherein the gradually changing signal is applied to a circuit which compares it to another signal (usually a standard).

244	.. With synchronization:

	This subclass is indented under subclass 237. Subject matter including means which detects a time characteristic of the input waveform, such as its zero crossing point, and produces a signal indicative thereof which is used to properly time the action of the final control device.

245	.. With nonelectrical condition sensing:

This subclass is indented under subclass 237. Subject matter wherein the means which responds to the output is a sensor which measures a nonelectrical condition such as heat of the system or its load, the condition being dependent upon the output of the system.

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236,	for zero switching devices with nonelectrical condition sensors.

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219,	Electric Heating, subclass 482 for power supply means with nonelectrical condition sensing having a heating system as the load.

246	.. With plural condition sensing:

This subclass is indented under subclass 237. Subject matter including means for sensing a condition of the system or its load, such means being in addition to the means responsive to deviation in the output of the system.

(1) Note. This subclass includes sensing combinations of voltage, current, power factor, etc.

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275,	for devices of this type wherein the final control device is a linearly acting three or more terminal semiconductive device.

247	. Using a transformer or inductor as the final control device:

This subclass is indented under subclass 234. Subject matter wherein the device within the systems which is the ultimate controller of the output is a transformer or inductor.

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301,	for transformers or inductors used in input level responsive devices.
305,	for transformers or inductors used in self-regulating devices.
328,	for transformers or inductors used in external or operator controlled devices.
355,	for miscellaneous transformer or inductor devices.

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336,	Inductor Devices, appropriate subclasses for transformer or inductor structure.
361,	Electricity: Electrical Systems and Devices, subclass 35 for transformer protection, and subclass 93.6 for abnormal current condition protection including transformer sensor.

248	.. Ferroresonant:

This subclass is indented under subclass 247. Subject matter wherein the transformer is associated with elements which causes it to resonate.

(1) Note. A ferroresonant transformer usually includes a saturable core and a capacitor (usually termed a ferrocapacitor) connected to one of the windings thereof.

(2) Note. Also included in this subclass are parametric transformers.

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306,	for self-regulating systems using ferroresonant transformers.

249	.. Controllably saturable:

This subclass is indented under subclass 247. Subject matter wherein the transformer or inductor includes a core, the level of saturation thereof being controllable.

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302,	for input level responsive devices of this type.
310,	for self-regulating devices of this type.
329,	for external or operator controlled devices of this type.

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330,	Amplifiers, subclass 8 for magnetic amplifiers.
336,	Inductor Devices, subclass 155 for inductive regulators with no moving parts.

250	... With specific core structure (e.g., gap, aperture, slot, permanent magnet):

	This subclass is indented under subclass 249. Subject matter wherein the core includes a gap, aperture, or slot therein or a permanent magnet associated therewith.

251	... With plural power windings:

This subclass is indented under subclass 249. Subject matter wherein the saturable transformer includes a plurality of windings through which the voltage or current which is to be controlled is conducted.

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332,	for external or operator controlled devices of this type.

252	.... In bridge configuration or in bridge arm:

This subclass is indented under subclass 251. Subject matter wherein the plural power windings are parts of a bridge circuit.

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333,	for external or operator controlled devices of this type.

253	.... On different cores:

This subclass is indented under subclass 251. Subject matter wherein each of the power windings is on a different core of a multicore transformer arrangement.

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335,	for external or operator controlled devices of this type.

254	... With electronic tube or a three or more terminal semiconductive device in control circuit:

This subclass is indented under subclass 249. Subject matter wherein the control circuit includes at least one electronics tube or three or more terminal semiconductive device connected to the control winding of the transformer.

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339,	for external or operator controlled devices of this type.

255	.. Having a variable length winding (e.g., tapped) as the final control device:

This subclass is indented under subclass 247. Subject matter wherein at least one of the windings of the transformer includes at least one contact intermediate the end contacts of the winding and means is provided to select between the several contacts.

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340,	for external or operator controlled devices of this type.

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200,	Electricity: Circuit Makers and Breakers, subclass 11 for tap changing switches, per se.
336,	Inductor Devices, subclass 137 for transformers with tap changing switches.

256	... With motor driven tap switch:

This subclass is indented under subclass 255. Subject matter wherein the means to select between the several contacts is operated by a motor.

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341,	for external or operator controlled devices of this type.

257	.... Including an electronic tube or a three or more terminal semiconductive device in control circuit:

	This subclass is indented under subclass 256. Subject matter including a signal processing circuit between the means responsive to the output and the motor, the signal processing circuit including at least one electronic tube or three or more terminal semiconductive device.

258	... With electronic tube or a three or more terminal semiconductive device as tap switch:

This subclass is indented under subclass 255. Subject matter wherein at least one of the several contacts is connected to the output through an electronic tube or a three or more terminal semiconductive device.

(1) Note. Devices in this subclass may include mechanical tap changers having a tube or semiconductive device associated therewith, usually for the purpose of arc suppression.

259	.. Having a winding in series with the source and load (e.g., buck-boost):

This subclass is indented under subclass 247. Subject matter wherein the load current is conducted from the source to the load through a winding of the transformer.

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344,	for external or operator controlled devices of this type.

260	... With motor in control circuit:

This subclass is indented under subclass 259. Subject matter including a signal processing circuit between the means responsive to the output level and the final control device, the signal processing circuit including a motor.

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256,	and 341, for motor-driven tap changers used in devices having variable length windings as final control devices.

261	... With saturable reactor in control circuit:

	This subclass is indented under subclass 259. Subject matter including a signal processing circuit between the means responsive to the output and the final control device, that signal processing circuit including a saturable reactor.

262	... Plural windings in series:

	This subclass is indented under subclass 259. Subject matter wherein the final control device includes a plurality of windings in series between the source and the load.

263	... With electronic tube or a three or more terminal semiconductive device in control circuit:

	This subclass is indented under subclass 259. Subject matter including a signal processing circuit between the means responsive to the output and the final control device, the signal processing circuit including at least one electronic tube or three or more terminal semiconductor device.

264	.. Having movable structure or winding:

This subclass is indented under subclass 247. Subject matter wherein the transformer includes movable magnetic shunts, shield, windings, or other such structure and it is the positioning of such structure that determines the ultimate output.

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347,	for external or operator controlled devices of this type.

265	. Using a three or more terminal: semiconductive device as the final control device:

This subclass is indented under subclass 234. Subject matter wherein the final control device within the output level responsive system is a transistor or semiconductor controlled rectifier.

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223,	for shunt regulators.
311,	for self-regulating devices.
349,	for external or operator controlled devices all using three or more terminal semiconductive devices as final control devices.

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219,	Electric Heating, subclass 501 for devices of this type having electric heating devices as a load.
327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 438+ and 530+ for subcombinations of systems using semiconductive devices as final control devices.

266	.. Including pre or post regulation:

This subclass is indented under subclass 265. Subject matter wherein the system includes two stages of regulation, at least one of which is responsive to the output level.

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224,	for plural stage regulators wherein one of the stages is in shunt with the source or load.

267	.. Including plural loads commonly controlled:

This subclass is indented under subclass 265. Subject matter wherein the system supplies several loads through commonly controlled devices.

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307,	Electrical Transmission or Interconnection Systems, subclass 11 for plural load systems which are responsive to each load individually.

268	.. Including plural final control devices:

This subclass is indented under subclass 265. Subject matter wherein the system includes a plurality of transistors or semiconductor controlled rectifiers, each contributing to the final control of the output.

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225,	for shunt regulators with plural final control devices.
350,	for external or operator controlled devices of this type.

269	... Linearly acting parallel connected:

	This subclass is indented under subclass 268. Subject matter wherein the plural devices are connected in parallel and are operated in their linear range.

270	... Linearly acting series connected:

	This subclass is indented under subclass 268. Subject matter wherein the plural devices are connected in series and are operated in their linear range.

271	... Switched (e.g., on-off control):

	This subclass is indented under subclass 268. Subject matter wherein the plural devices are operated such that they are either conductive or nonconductive.

272	.... Parallel connected:

	This subclass is indented under subclass 271. Subject matter wherein the plural devices are connected in parallel.

273	.. Linearly acting:

	This subclass is indented under subclass 265. Subject matter wherein the system includes a single final control device which is operated in its linear range.

274	... With threshold detection:

This subclass is indented under subclass 273. Subject matter wherein the system includes means which responds within a predetermined range or the means abruptly changes its conductive state at a predetermined level of the output.

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284,	for switching regulators with threshold detection.

275	... With plural condition sensing:

This subclass is indented under subclass 273. Subject matter including means for sensing a condition of the system or its load, such means being in addition to the means responsive to deviation in the output of the system.

(1) Note. This subclass includes sensing combinations of voltage, current, power factor, etc.

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246,	for devices of this type wherein the final control device is a phase controlled switch.
285,	for switching regulators with plural condition sensing.

276	.... For protection system:

This subclass is indented under subclass 275. Subject matter including means to detect conditions which could cause possibly destructive failure of the system, its components or the load and means to prevent such failure.

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361,	Electricity: Electrical Systems and Devices, subclasses 1 and 18 for protective systems, per se.

277	..... With current sensor:

This subclass is indented under subclass 276. Subject matter including means to sense the load current.

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361,	Electricity: Electrical Systems and Devices, subclasses 93.1+ for abnormal current sensors in protective systems.

278	...... Having base-emitter of transistor coupled across sensor:

	This subclass is indented under subclass 277. Subject matter wherein the current sensor includes an impedance connected in series with the load and the base-emitter junction of a transistor is connected across the impedance.

279	.... Including final control device parameter:

	This subclass is indented under subclass 275. Subject matter wherein the additional condition is a parameter of the final control device such as its temperature, the current it is carrying, or the voltage across it.

280	... With a specific feedback amplifier (e.g., integrator, summer):

This subclass is indented under subclass 273. Subject matter including a signal processing circuit between the means responsive to the output level and the final control device, the signal processing circuit including an amplifier in a feedback path, the amplifier including such elements as cascaded stages, summing junctions, or additional feedback circuitry.

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330,	Amplifiers, appropriate subclasses for amplifiers, per se.

281	... With reference voltage circuitry:

This subclass is indented under subclass 273. including a signal processing circuit between the means responsive to the output level and the final control device, the signal processing circuit including means to develop a standard voltage which is used as a reference in the signal processing circuit.

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313,	for self-regulating devices which derive a voltage reference.

282	.. Switched (e.g., switching regulators):

This subclass is indented under subclass 265. Subject matter wherein the system includes a single final control device which is operated in such manner that it is either conductive or nonconductive.

(1) Note. The most common devices found herein are regulators wherein a switch such as a transistor is operated in a closed or open state. When closed an inductor typically stores energy, and when open, a flyback or catch diode will continue the flow of current or release of energy through the inductor to the load.

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222,	for shunt type switching regulators.
351,	for external or operator controlled switching regulators.

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363,	Electric Power Conversion Systems, subclass 15 and 124 for D.C. to A.C. to D.C. converters.

283	... Digitally controlled:

This subclass is indented under subclass 282. Subject matter including a signal processing circuit between the means responsive to the output and the final control device, that signal processing circuit including logic elements which process a signal having discrete states.

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211,	and the subclasses noted in the definition thereof for digitally controlled systems.

284	... With threshold detection:

This subclass is indented under subclass 282. Subject matter wherein the system includes means which responds within a predetermined range of the output or the means abruptly changes its conductive state at a predetermined level of the output.

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274,	for linearly acting regulators with threshold detection.

285	... With plural condition sensing:

This subclass is indented under subclass 282. Subject matter including means for sensing a condition of the system or its load, such means being in addition to the means responsive to deviation in the output of the system.

(1) Note. This subclass includes sensing combinations of voltage, current, power factor, etc.

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246,	for devices of this type wherein the final control device is a phase controlled switch.
275,	for devices of this type wherein the final control device is a linearly acting three or more terminal semiconductive device.

286	.... Including filter sensing:

This subclass is indented under subclass 285. Subject matter wherein the additional condition is a condition of a filter used to smooth the output of the switched final control device.

(1) Note. The filter is typically a diode, choke, capacitor arrangement and the sensor is usually associated with the choke element.

287	..... In flyback path:

	This subclass is indented under subclass 286. Subject matter wherein the filter includes a diode (typically termed flyback, catch, or freewheeling diode) and the sensor is disposed in the diode path.

288	... With ramp generator or controlled capacitor charging:

This subclass is indented under subclass 282. Subject matter including circuitry which produces a gradually changing signal which is ultimately proportional to the output of the device.

(1) Note. The changing signal may take the form of a sawtooth with a repeating ramp and return to an initial value. Controlled capacitor charging involves charging a capacitor to some predetermined value at which value a controllable device such as a transistor, unijunction transistor, or programmable unijunction transistor goes into another state of conduction or exerts a controlling influence on another device.

SEE OR SEARCH THIS CLASS, SUBCLASS:

242,	and 326, for other systems including ramp generators or controlled capacitor charging circuits.

SEE OR SEARCH CLASS:

327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 131+ for a miscellaneous ramp or sawtooth waveform generator.

289	... With base drive control dissipation:

This subclass is indented under subclass 282. Subject matter including means connected to the base of a switching transistor to minimize the dissipation of power within the transistor at its turn-on and turn-off times.

SEE OR SEARCH CLASS:

327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 579 and 585 for miscellaneous devices concerning minority carrier storage.

290	... With inductor in control circuit:

	This subclass is indented under subclass 282. Subject matter including a signal processing circuit between the means responsive to the output level and the final control device, the signal processing circuit including an inductor.

291	. Using an electronic tube as the final control device:

	This subclass is indented under subclass 234. Subject matter wherein the final control device within the output level responsive system is an electric space discharge device such as a vacuum or gas tube.

292	.. With a three or more terminal semiconductive device in control circuit:

	This subclass is indented under subclass 291. Subject matter including a signal processing circuit between the output level responsive means and the final control device, the signal processing circuit including a transistor or semiconductive controlled rectifier.

293	. Using an impedance as the final control device:

This subclass is indented under subclass 234. Subject matter wherein the final control device within the output level responsive system is an impedance such as a resistor, capacitor, or diode.

(1) Note. Inductors are not included herein. See search notes below.

SEE OR SEARCH THIS CLASS, SUBCLASS:

208,	and the subclasses noted in the definition thereof, for impedances used as final control devices in other systems.
247,	for inductors.

294	.. Hall effect device, magnetoresistor or thermistor:

	This subclass is indented under subclass 293. Subject matter wherein the impedance is a Hall effect device or a resistor which changes its resistance in accordance with the strength of a magnetic field or temperature.

295	.. Pressure sensitive resistor:

	This subclass is indented under subclass 293. Subject matter wherein the impedance is a resistor which changes its resistance in accordance with the pressure applied thereto.

296	.. Liquid contact resistor:

	This subclass is indented under subclass 293. Subject matter wherein the impedance is a resistor which changes its resistance in accordance with the degree of contact with a conductive liquid.

297	.. Plural selective resistors:

	This subclass is indented under subclass 293. Subject matter wherein a plurality of individual resistors are connected in a circuit which allows each resistor or a combination of resistors to be used as the final control device.

298	.. Variable resistor:

	This subclass is indented under subclass 293. Subject matter wherein different portions or a combination of portions of a single resistance element may be used as the final control device.

299	INPUT LEVEL RESPONSIVE:

This subclass is indented under the class definition. Subject matter which maintains an output at a desired level through the use of control means responsive to the input level.

(1) Note. Although not specifically included within each of the following definitions, input level responsive systems usually include (a) some means which produces a signal indicative of the input level of the system, (b) some processing circuit which makes use of the signal mentioned above, and (c) a final control device which is controlled by the output of the processing circuit, thus producing a controlled output of the system.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 538+ for regulators of this type having a semiconductive device as the claimed load.

300	. Phase controlled switching using electronic tube or a three or more terminal semiconductive device:

This subclass is indented under subclass 299. Subject matter wherein the input is alternating current and the final control device is an electronic tube or three or more terminal semiconductive device which is caused to change to its conductive state at a controllable point following the zero axis crossing of the input waveform.

SEE OR SEARCH THIS CLASS, SUBCLASS:

237,	for output level responsive phase controlled switching systems.
320,	for external or operator controlled phase controlled switching systems.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 453+ for semiconductor controlled rectifiers which are involved in phase switching.

301	. Using a transformer or inductor as the final control device:

This subclass is indented under subclass 299. Subject matter wherein the device within the system which is the ultimate controller of the output is a transformer or inductor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

247,	for transformers or inductors used in output level responsive devices.
305,	for transformers or inductors used in self-regulating devices.
328,	for transformers or inductors used in external or operator controlled devices.
355,	for miscellaneous transformer or inductor devices.

SEE OR SEARCH CLASS:

336,	Inductor Devices, appropriate subclasses for transformer or inductor structure.
361,	Electricity: Electrical Systems and Devices, subclass 35 for transformer protection, and subclass 93.6 for abnormal current condition protection including transformer sensor.

302	.. Saturable:

This subclass is indented under subclass 301. Subject matter wherein the transformer or inductor includes a core, the level of saturation thereof being controllable.

SEE OR SEARCH THIS CLASS, SUBCLASS:

249,	for output level responsive devices of this type.
310,	for self-regulating devices of this type.
329,	for external or operator controlled devices of this type.

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330,	Amplifiers, subclass 8 for magnetic amplifiers.
336,	Inductor Devices, subclass 155 for inductive regulators with no moving parts.

303	. Using a linearly acting final control device:

	This subclass is indented under subclass 299. Subject matter wherein the final control device is operated within its linear range.

304	SELF-REGULATING (E.G., NONRETROACTIVE):

This subclass is indented under the class definition. Subject matter which maintains an output at a desired level through the use of means which exhibit inherent limiting characteristics.

(1) Note. Example of means which exhibit inherent limiting characteristics are zener diodes and neon tubes.

305	. Using a transformer or inductor as the final control device:

This subclass is indented under subclass 304. Subject matter wherein the device within the system which is the ultimate controller of the output is a transformer or inductor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

247,	for transformers or inductors used in output level responsive devices.
301,	for transformers or inductors used in input level responsive devices.
328,	for transformers or inductors used in external or operator controlled devices.
355,	for miscellaneous transformer or inductor devices.

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336,	Inductor Devices, appropriate subclasses for transformer or inductor structure.
361,	Electricity: Electrical Systems and Devices, subclass 35 for transformer protection, and subclass 93.6 for abnormal current condition protection including transformer sensor.

306	.. Ferroresonant:

This subclass is indented under subclass 305. Subject matter wherein the transformer is associated with elements which causes it to resonate.

(1) Note. A ferroresonant transformer usually includes a saturable core and a capacitor (usually termed a ferrocapacitor) connected to one of the windings thereof.

(2) Note. Also included in this subclass are parametric transformers.

SEE OR SEARCH THIS CLASS, SUBCLASS:

248,	for output level responsive systems using ferroresonant transformers.

307	... With plural cores:

	This subclass is indented under subclass 306. Subject matter wherein the ferroresonant transformer has at least two cores.

308	... With core having an air gap or magnetic shunt:

	This subclass is indented under subclass 306. Subject matter wherein the core of the ferroresonant transformer includes an air gap within one of the legs thereof or a magnetically permeable leg which bridges the core.

309	.... Including a ferrocapacitor across a tertiary winding:

	This subclass is indented under subclass 308. Subject matter wherein the ferroresonant transformer has at least three windings and a capacitor is connected in a series closed circuit with one of the windings.

310	.. Controllably saturable:

This subclass is indented under subclass 305. Subject matter wherein the transformer includes a core, the level of saturation thereof being controllable.

SEE OR SEARCH THIS CLASS, SUBCLASS:

249,	for output level responsive devices of this type.
302,	for input level responsive devices of this type.
329,	for external or operator controlled devices of this type.

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330,	Amplifiers, subclass 8 for magnetic amplifiers.
336,	Inductor Devices, subclass 155 for inductive regulators with no moving parts.

311	. Using a three or more terminal semiconductive device as the final control device:

This subclass is indented under subclass 304. Subject matter wherein the final control device within the self-regulating system is a transistor or semiconductor controlled rectifier.

SEE OR SEARCH THIS CLASS, SUBCLASS:

223,	for shunt regulators.
265,	for output level responsive devices.
349,	for external or operator controlled devices, all using three or more terminal semiconductive devices as final control devices.

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219,	Electric Heating, subclass 501 for devices of this type having electric heating devices as a load.
327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 438+ and 530+ for subcombinations of systems using semiconductive devices as final control devices.

312	.. For current stabilization:

	This subclass is indented under subclass 311. Subject matter wherein the system functions to regulate current therethrough.

313	... To derive a voltage reference (e.g., band gap regulator:

This subclass is indented under subclass 312. Subject matter wherein the current within the device is stabilized for the purpose of producing a stabilized reference voltage at its output.

(1) Note. Devices herein generate a reference potential related to an inherent property such as the band gap potential of a semiconductor material such as silicon. The band gap potential is the difference in energy between the energy level of the bottom of the conduction band and the energy level of the top of the valence band.

314	.... With additional stage:

	This subclass is indented under subclass 313. Subject matter wherein an additional controlled device is connected between the final control device circuit and the ultimate output.

315	... Including parallel paths (e.g., current mirror):

This subclass is indented under subclass 312. Subject matter wherein at least two stabilized current paths are in parallel with each other, usually the currents bearing a predetermined relation to each other.

SEE OR SEARCH CLASS:

327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 530+ for semiconductor device bias supplies of this type.
330,	Amplifiers, subclass 288 for current mirror amplifiers.

316	.... With amplifier connected to or between current paths:

	This subclass is indented under subclass 315. Subject matter wherein an additional controlled device is connected between the stabilized current paths or as an output to at least one of the paths.

317	.... With switched final control device:

This subclass is indented under subclass 315. Subject matter wherein the controlling device within at least one of the paths is operated in a switching mode.

SEE OR SEARCH THIS CLASS, SUBCLASS:

272,	for parallel connected, switched final control devices in output level responsive systems.

318	EXTERNAL OR OPERATOR CONTROLLED:

This subclass is indented under the class definition. Subject matter including means for controlling an output through the action of an externally generated signal or the adjustment of an element within the system by an operator of the system.

SEE OR SEARCH THIS CLASS, SUBCLASS:

234,	for systems which are controlled in response to the output level of the system.
299,	for systems which are controlled in response to the input level of the system.
304,	for systems which are controlled by the inherent characteristics of the elements which make up the system.

319	. Zero switching:

This subclass is indented under subclass 318. Subject matter wherein the input is alternating current and the final control device is a switch which is caused to change to its conductive state at or about the zero axis crossing of the input waveform.

(1) Note. Usually, the average power applied to the load is controlled by varying the number of half or full cycles of input waveform that is permitted to flow to the load.

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235,	for output level responsive systems of this type.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 451+ for semiconductor controlled rectifiers which are involved in zero point switching.

320	. Phase controlled switching using electronic tube or a three or more terminal semiconductive device:

This subclass is indented under subclass 318. Subject matter wherein the input is alternating current and the final control device is an electronic tube or three or more terminal semiconductive device which is caused to change to its conductive state at a controllable point following the zero axis crossing of the input waveform.

SEE OR SEARCH THIS CLASS, SUBCLASS:

237,	for output responsive phase controlled switching systems.
300,	for input responsive phase controlled switching systems.

SEE OR SEARCH CLASS:

327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 447+ for semiconductor controlled rectifiers which are involved in phase switching.

321	.. With soft start:

This subclass is indented under subclass 320. Subject matter wherein at the time of start up of the system, the output is gradually increased over a plurality of cycles from zero to the desired level.

SEE OR SEARCH THIS CLASS, SUBCLASS:

238,	for output responsive systems of this type.

322	.. With digital control:

This subclass is indented under subclass 320. Subject matter including a control signal processing circuit which includes logic elements which process a signal having discrete states.

SEE OR SEARCH THIS CLASS, SUBCLASS:

211,	for reactive power systems which are digitally controlled.
241,	for digitally controlled phase controlled switching systems.
283,	for output responsive digitally controlled solid-state systems.

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326,	Electronic Digital Logic Circuitry, appropriate subclasses for digital logic circuits.

323	.. With interval timer:

This subclass is indented under subclass 320. Subject matter which includes means for predetermining the length of time of operation of the system or a part thereof.

SEE OR SEARCH THIS CLASS, SUBCLASS:

319,	for zero switching devices which may include interval timers.

324	.. Using single unidirectional element with bidirectional pass:

This subclass is indented under subclass 320. Subject matter wherein the final control device is capable of carrying current in only one direction but the circuit is arranged in such fashion that both polarities of the input are passed or controlled.

(1) Note. The unidirectional element may be a tube or semiconductive device connected within a diode bridge circuit so as to pass both polarities of the alternating current, or a tube or a semiconductive device bridged by a single diode whereby one polarity of the applied A.C. is controlled and the other polarity is uncontrolled.

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239,	for output responsive systems of this type.

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327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclass 448 for miscellaneous gating SCR"s in a bridge.

325	.. With a three or more terminal semiconductive device in trigger circuit:

	This subclass is indented under subclass 320. Subject matter including a control signal shaping circuit between the controlling input and the final control element, the shaping circuit including at least one transistor or SCR device.

326	... Including ramp generator or controlled capacitor charging:

This subclass is indented under subclass 325. Subject matter including circuitry which produces a gradually changing signal (usually by controlling the rate of charge of a capacitor) which is then used in the trigger circuit to produce the controlling input to the final control element.

(1) Note. The changing signal may take the form of a sawtooth with a repeating ramp and return to an initial value. Controlled capacitor charging involves charging a capacitor to some predetermined value at which value a controllable device such as a transistor, unijunction transistor, or programmable unijunction transistor goes into another state of conduction or exerts a controlling influence on another device.

SEE OR SEARCH THIS CLASS, SUBCLASS:

242,	and 288, for ramp generators used in output level responsive systems.

SEE OR SEARCH CLASS:

327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 131+ for a miscellaneous ramp or sawtooth waveform generator.

327	.. With passive element only in trigger circuit:

	This subclass is indented under subclass 320. Subject matter including a control signal shaping circuit between the controlling input and the final control element, the shaping circuit including passive elements such as resistors and capacitors only.

328	. Using a transformer or inductor as the final control device:

This subclass is indented under subclass 318. Subject matter wherein the device within the system which is the ultimate controller of the output is a transformer or inductor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

247,	for systems of this type which are responsive to the output level of the system.
301,	for transformers or inductors used in input level responsive devices.
305,	for transformers or inductors used in self-regulating devices.
355,	for miscellaneous transformer or inductor devices.

SEE OR SEARCH CLASS:

336,	Inductor Devices, appropriate subclasses for transformer or inductor structure.
361,	Electricity: Electrical Systems and Devices, subclass 35 for transformer protection, and subclass 93.6 for abnormal current condition protection including transformer sensor.

329	.. Controllably saturable:

This subclass is indented under subclass 328. Subject matter wherein the transformer includes a core, the level of saturation thereof being controllable.

SEE OR SEARCH THIS CLASS, SUBCLASS:

249,	for output level responsive devices of this type.
302,	for input level responsive devices of this type.
310,	for self-regulating devices of this type.

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330,	Amplifiers, subclass 8 for magnetic amplifiers.
336,	Inductors Devices, subclass 155 for inductive regulators with no moving parts.

330	... With permanent magnet:

	This subclass is indented under subclass 329. Subject matter which includes a permanent magnet as part of or in addition to the saturable core.

331	... With core having a gap, aperture, or slot:

	This subclass is indented under subclass 329. Subject matter wherein the core includes a gap, aperture, or slot therein.

332	... With plural power windings:

This subclass is indented under subclass 329. Subject matter wherein the saturable transformer includes a plurality of windings through which the voltage or current which is to be controlled is conducted.

SEE OR SEARCH THIS CLASS, SUBCLASS:

251,	for output level responsive devices of this type.

333	.... In bridge configuration or in bridge arm:

This subclass is indented under subclass 332. Subject matter wherein the plural power windings are parts of a bridge circuit.

SEE OR SEARCH THIS CLASS, SUBCLASS:

252,	for output level responsive devices of this type.

334	.... On different legs of single core:

	This subclass is indented under subclass 332. Subject matter wherein each of the power windings is on a different leg of a multilegged core.

335	.... On different cores:

This subclass is indented under subclass 332. Subject matter wherein each of the power windings is on a different core of a multicore transformer arrangement.

SEE OR SEARCH THIS CLASS, SUBCLASS:

253,	for output level responsive devices of this type.

336	..... Multistage:

	This subclass is indented under subclass 335. Subject matter wherein the output of all but the last transformer is connected as the input of the succeeding transformer.

337	..... Push-pull:

	This subclass is indented under subclass 335. Subject matter wherein the different cores of the transformer arrangement operate on different polarities of the voltage or current to be treated.

338	... With plural cores:

	This subclass is indented under subclass 329. Subject matter wherein a single power winding is wound about plural adjacent cores.

339	... Including an electronic tube or a three or more terminal semiconductive device in control circuit:

This subclass is indented under subclass 329. Subject matter wherein the control circuit includes at least one electronic tube or three or more terminal semiconductive device connected to the control winding of the transformer.

SEE OR SEARCH THIS CLASS, SUBCLASS:

254,	for output level responsive devices of this type.

340	.. Having a variable length winding (e.g., tapped) as the final control device:

This subclass is indented under subclass 328. Subject matter wherein at least one of the windings of the transformer includes at least one contact intermediate the end contacts of the winding and means is provided to select between the several contacts.

SEE OR SEARCH THIS CLASS, SUBCLASS:

255,	for output level responsive devices of this type.

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200,	Electricity: Circuit Makers and Breakers, subclass 11 for tap changing switches, per se.
336,	Inductor Devices, subclass 137 for transformers with tap changing switches.

341	... With motor driven tap switch:

This subclass is indented under subclass 340. Subject matter wherein the means to select between the several contacts is operated by a motor.

SEE OR SEARCH THIS CLASS, SUBCLASS:

256,	for output level responsive devices of this type.

342	... With other transformer:

	This subclass is indented under subclass 340. Subject matter wherein the system includes a transformer in addition to the tapped transformer.

343	... With a three or more terminal semiconductive device:

This subclass is indented under subclass 340. Subject matter including a transistor or SCR as part of a control circuit within the device or having a switching means connected to each tap, the switching means being a transistor or SCR.

SEE OR SEARCH THIS CLASS, SUBCLASS:

258,	for transistors or SCRs used as tap switches in output level responsive devices.

344	.. Having a winding in series with the source and load (e.g., buck-boost):

This subclass is indented under subclass 328. Subject matter wherein the load current is conducted from the source to the load through a winding of the transformer.

SEE OR SEARCH THIS CLASS, SUBCLASS:

259,	for output level responsive devices of this type.

345	.. Having a switch in series with winding:

This subclass is indented under subclass 328. Subject matter wherein at least one of the windings of the transformer has a switch in series therewith and it is the relative lengths of the on and off times of the switch that determines the ultimate output.

SEE OR SEARCH THIS CLASS, SUBCLASS:

222,	for shunt regulators having a choke and switch connected across the source circuit.

346	.. Having series-parallel connectable windings:

	This subclass is indented under subclass 328. Subject matter wherein the transformer includes a plurality of windings which are arranged in such fashion that they may be selectably connected in series or parallel or a combination series-parallel circuit.

347	.. Having movable structure or winding:

This subclass is indented under subclass 328. Subject matter wherein the transformer includes movable magnetic shunts, shields, windings, or other such structure and it is the positioning of such structure that determines the ultimate output.

SEE OR SEARCH THIS CLASS, SUBCLASS:

264,	for output level responsive devices of this type.

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340,	Communications: Electrical, subclass 195 for inductive telemetering transmitters having movable structure or windings.

348	... Including rotary motion:

	This subclass is indented under subclass 347. Subject matter wherein the structure or winding is movable about an axis.

349	. Using a three or more terminal semiconductive device as the final control device:

This subclass is indented under subclass 318. Subject matter wherein the device which ultimately controls the level of the output is a transistor or SCR.

SEE OR SEARCH THIS CLASS, SUBCLASS:

223,	for shunt regulators.
265,	for output level responsive devices.
311,	for self-regulating devices, all using three or more terminal semiconductive devices as final control devices.

SEE OR SEARCH CLASS:

219,	Electric Heating, subclass 501 for devices of this type having electric heating devices as a load.
327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 438+ and 530+ for subcombinations of systems using semiconductive devices as final control devices.

350	.. Including plural final control devices:

This subclass is indented under subclass 349. Subject matter wherein the system includes a plurality of transistors or semiconductor controlled rectifiers, each contributing to the final control of the output.

SEE OR SEARCH THIS CLASS, SUBCLASS:

225,	for shunt regulators with plural final control devices.
268,	for output level responsive devices of this type.

351	.. Switched (e.g., switching regulators):

This subclass is indented under subclass 349. Subject matter wherein the system includes a single final control device which is operated in such a manner that it is either conductive or nonconductive.

SEE OR SEARCH THIS CLASS, SUBCLASS:

222,	for shunt type switching regulators.
282,	for output level responsive switching regulators.

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363,	Electric Power Conversion Systems, subclass 15 and 124 for D.C. to A.C. to D.C. converters.

352	. Using an impedance as the final control device:

This subclass is indented under subclass 318. Subject matter wherein the final control device within the system is an impedance such as a resistor, capacitor, or diode.

(1) Note. Inductors are not included herein. See subclass 328 above.

SEE OR SEARCH THIS CLASS, SUBCLASS:

208,	and the subclasses noted in the definition thereof, for impedances used as final control devices in other systems.

353	.. Resistor:

	This subclass is indented under subclass 352. Subject matter wherein the impedance is a resistor.

354	... Selective:

This subclass is indented under subclass 353. Subject matter wherein a plurality of individual resistors are connected in a circuit which allows each resistor or a combination of resistors to be used as the final control device.

SEE OR SEARCH THIS CLASS, SUBCLASS:

297,	for output level responsive devices of this type.

355	INCLUDING A TRANSFORMER OR AN INDUCTOR:

This subclass is indented under the class definition. Subject matter in which a load device not elsewhere classified is supplied with electricity by a transformer, or the combination of a transformer or inductor with circuitry not elsewhere classifiable.

SEE OR SEARCH THIS CLASS, SUBCLASS:

206,	214, 215, 232, 247, 301, 305, and 328, for transformers or inductors used in various control systems within this class.

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336,	Inductor Devices, for transformers or inductors, per se.

356	. With compensation:

	This subclass is indented under subclass 355. Subject matter wherein the transformer has associated therewith circuitry which corrects for undesired phase shift or other discrepancy between the expected and actual outputs of the transformer.

357	.. For current transformer:

This subclass is indented under subclass 356. Subject matter wherein the transformer is a current transformer.

(1) Note. See the definition of current transformer in subclass 358 below.

358	. Current transformer:

This subclass is indented under subclass 355. Subject matter wherein the transformer is an instrument transformer having its primary winding (which may be a single conductor) connected in series with a circuit carrying the current to be measured.

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324,	Electricity: Measuring and Testing, subclass 127 for measuring devices including transformers.

359	. Potential transformer:

This subclass is indented under subclass 355. Subject matter wherein the transformer is an instrument transformer having its primary winding connected in parallel with a circuit, the voltage of which is to be measured.

SEE OR SEARCH CLASS:

324,	Electricity: Measuring and Testing, subclass 127 for measuring devices including transformers.

360	. Superconductive:

This subclass is indented under subclass 355. Subject matter wherein the transformer includes a winding whose resistance is essentially zero.

SEE OR SEARCH CLASS:

327,	Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, subclasses 527+ for miscellaneous superconductive circuits.

361	. Polyphase or plural transformers:

This subclass is indented under subclass 355. Subject matter wherein the transformer arrangement is adapted to handle more than one phase of electric energy or is made up of more than one transformer.

SEE OR SEARCH CLASS:

336,	Inductor Devices, subclass 5 for polyphase transformers, per se.

362	. With core having permanent magnet or air gap:

This subclass is indented under subclass 355. Subject matter including a permanent magnet associated with the core of the transformer or having a gap in one of the legs thereof.

SEE OR SEARCH THIS CLASS, SUBCLASS:

250,	308, 330, and 331, for various devices including transformers with cores of this type.

363	. Inductor with or in a bridge:

This subclass is indented under subclass 355. Subject matter including at least one inductor in combination with a bridge circuit.

SEE OR SEARCH THIS CLASS, SUBCLASS:

365,	for other impedances in bridge circuits.

364	INCLUDING AN IMPEDANCE:

This subclass is indented under the class definition. Subject matter in which a load device not elsewhere classified is supplied with electricity through an impedance arrangement or a combination of impedances not elsewhere classifiable.

(1) Note. Inductors are not included herein. See subclass 355 above.

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208,	and the subclasses noted in the definition thereof, for impedances used as final control devices in other systems.

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338,	Electrical Resistors, for resistors, per se.
361,	Electricity: Electrical Systems and Devices, subclass 271 and 500+ for capacitors, per se.

365	. In a bridge:

This subclass is indented under subclass 364. Subject matter wherein the impedance are connected in a bridge configuration.

SEE OR SEARCH CLASS:

236,	Automatic Temperature and Humidity Regulation, subclasses 69 , 74, 78, and 91 for temperature regulating systems which include impedance bridge networks as the control means.
318,	Electricity: Motive Power Systems, subclasses 663 and 674 for electric motor position servomechanisms which may include an impedance bridge network; subclass 294 for motor reversing systems wherein the armature current reversal means includes an impedance bridge network; and subclass 535 for motor field circuit control systems which include an impedance bridge network.
322,	Electricity: Single Generator Systems, subclass 77 for single generator systems where the generator field circuit is controlled by means of an impedance bridge network.
324,	Electricity: Measuring and Testing, appropriate subclasses, especially subclasses 98 , 101, and 600+ for electric testing systems involving impedance bridge arrangements.
330,	Amplifiers, subclasses 72 , 146, and 175 for amplifier systems including, respectively, series arranged tubes with each tube in the arm of a bridge; a bridge with a tube in at least one arm; and a Wheatstone bridge network in a coupling circuit.
331,	Oscillators, subclasses 110 and 138 for bridge type oscillators wherein the frequency determining element of the oscillator comprises a balanced lattice or similar type network having two pairs of conjugately related terminals.
332,	Modulators, subclass 172 for a an amplitude modulator including bridge arrangements.
333,	Wave Transmission Lines and Networks, subclass 1 for hybrid type networks which may include Wheatstone bridge impedance arrangements.
340,	Communications: Electrical, subclasses 510 , 563, and 599 for condition responsive systems using a Wheatstone bridge.
363,	Electric Power Conversion Systems, subclasses 17 , 58, 68, 98, 132, and 136 for converters including bridges.

366	.. Thermistor:

This subclass is indented under subclass 365. Subject matter wherein the bridge includes a thermistor in at least one of its arms.

SEE OR SEARCH THIS CLASS, SUBCLASS:

369,	for nonbridge thermistor arrangements.

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374,	Thermal Measuring and Testing, subclasses 183+ for similar subject matter controlling an indicator.

367	.. Resistor only:

	This subclass is indented under subclass 365. Subject matter wherein the bridge includes resistance elements only.

368	. Hall effect device or magnetoresistor:

This subclass is indented under subclass 364. Subject matter wherein the impedance arrangement includes a device which changes its impedance in accordance with the strength of a magnetic field applied thereto.

SEE OR SEARCH CLASS:

338,	Electrical Resistors, subclass 32 for magnetic field responsive resistors, per se.

369	. Thermistor or resistor:

This subclass is indented under subclass 364. Subject matter wherein the impedance arrangement includes at least one resistor which may be responsive to temperature.

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374,	Thermal Measuring and Testing, subclasses 183+ for similar subject matter controlling an indicator.

370	.. With capacitor:

	This subclass is indented under subclass 369. Subject matter having a capacitor in addition to the resistor.

371	MISCELLANEOUS:

	This subclass is indented under the class definition. Subject matter not classifiable above.

901	STARTING CIRCUITS:

	Art collection of disclosures including means to initiate circuit operation or to overcome an initial inoperative state of an element or circuit.

902	OPTICAL COUPLING TO SEMICONDUCTOR:

Art collection of disclosures including light emitting means coupled to a photoresponsive semiconductor.

SEE OR SEARCH CLASS:

250,	Radiant Energy, subclass 551 for signal isolators, including optically coupled light emitters and semiconductor light receivers.
257,	Active Solid-State Devices (e.g., Transistors, Solid-State Diodes), subclasses 80 through 85for incoherent light emitters coupled to active solid-state device light detector elements, per se.

903	PRECIPITATORS:

	Art collection of disclosures including power systems or regulators where the load is an electrostatic precipitator which removes particulate matter such as dirt from a gas, such as air.

904	TOUCH SYSTEMS:

	Art collection of disclosures including the sensing of a change in capacitance, temperature, or other condition produced by a person touching or being in the immediate proximity of a part of the system.

905	LAMP DIMMER STRUCTURE:

	Art collection of disclosures including an electrical control circuit housed or positioned within structure, such as a wall socket or a lamp socket, related to manually varying or controlling the output of a lamp.

906	SOLAR CELL SYSTEMS:

	Art collection of disclosures including regulators having as a power source an array of solar cells and/or battery systems such as those in spacecraft.

907	TEMPERATURE COMPENSATION OF SEMICONDUCTOR:

Art collection of disclosures including semiconductors exhibiting temperature dependencies and means are provided to compensate for or to offset the temperature dependency.

SEE OR SEARCH CLASS:

250,	Radiant Energy, subclass 238 for temperature compensated photocells.
257,	Active Solid-State Devices (e.g., Transistors, Solid-State Diodes), subclasses 706 , 707, and 712-722 for such devices with cooling means.