Manual of U.S. Patent Classification
as of June 30, 2000

Class
388
ELECTRICITY: MOTOR CONTROL SYSTEMS

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Subclass		Title
ClassTitle		===> ELECTRICITY: MOTOR CONTROL SYSTEMS
		This Class 388 is considered to be an integral part of Class 318 (see the Class 318 schedule for the two positions of this Class in schedule hierarchy). This Class retains all pertinent definitions and class lines of Class 318.
800		CLOSED LOOP SPEED CONTROL SYSTEM FOR DC MOTOR WITH COMMUTATOR
801		. Field control, or field and armature control, by digital or combined analog and digital circuitry
803		. Field control, or field and armature control, by analog (only) circuitry
804		. . By pulse width or duty cycle modification
805		. . By phase or frequency modification
806		. . By voltage or current modification
807		. . . With variable impedance
808		. . By selection of windings
809		. Armature control by digital or combined analog and digital circuitry
811		. . By pulse width or duty cycle modification
812		. . By phase and frequency modification
813		. . By phase modification
814		. . By frequency modification
815		. . By voltage or current modification
816		. Analog armature control
819		. . By pulse width or duty cycle modification
820		. . By phase or frequency modification
821		. . By voltage and current modification
822		. . By voltage modification
823		. . By current modification
824		. . By variable impedance (e.g., potentiometer)
825		OPEN LOOP SPEED CONTROL SYSTEM FOR DC MOTOR WITH COMMUTATOR
826		. Field control, or field and armature control
827		. . With plural selectable speeds (e.g., manual switch)
828		. Armature control by digital or combined analog and digital circuitry
829		. . By pulse width or duty cycle modification
830		. Analog armature control
831		. . By pulse width or duty cycle modification
832		. . By frequency modification
833		. . By voltage or current modification
834		. . By selection of windings
835		. . By control of motor structure
836		. . . Position or number of brushes
837		. . By periodic mechanical switch
838		. . With plural selectable speeds (e.g., with manual switch, potentiometer
839		. . . By selecting impedance
840		. . . . Resistive
841		. . . . Inductive
842		CLOSED LOOP ACCELERATION CONTROL SYSTEM FOR DC MOTOR WITH COMMUTATOR
843		. Field control, or field and armature control
844		. Armature control
847		. . By voltage or current modification
848		OPEN LOOP ACCELERATION CONTROL SYSTEM FOR DC MOTOR WITH COMMUTATOR
849		. Field control, or field and armature control
850		. . By transformer or inductive device
851		. . By patterned switch
852		. . By insertion of resistance
853		. Armature control
854		. . By voltage or current modification
855		. . By selectable or variable impedance
856		. . . By insertion of resistance or shorting of circuit
857		. . . . With relay
858		. . . . . Time delay relay
859		. . . . With patterned switch
860		. . . Manual
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		CROSS-REFERENCE ART COLLECTIONS
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900		SPECIFIC SYSTEM OPERATIONAL FEATURE
901		. Sample and hold
902		. Compensation
903		. Protective (e.g., voltage or current limit)
904		. Stored velocity profile
905		. Armature and field windings connected in series (i.e., series motor)
906		. Proportional-integral system
907		SPECIFIC CONTROL CIRCUIT ELEMENT OR DEVICE
907.2		. Bridge circuit
907.5		. Computer or microprocessor
908		. Frequency to voltage converter
909		. Monitoring means
910		. Operational/differential amplifier
911		. Phase locked loop
912		. Pulse or frequency counter
913		. Saturable reactor, space discharge device, or magnetic amplifier
914		. . Thyratron or ignitron
915		. Sawtooth or ramp waveform generator
916		. Threshold circuit
917		. Thyristor or SCR
918		. . Trigger by unijunction transistor
919		. . Triggered by resistor or capacitor
920		. . Chopper
921		. Timer or time delay means
922		. Tuned or resonant circuit
923		SPECIFIC FEEDBACK CONDITION OR DEVICE
924		. Centrifugal device (e.g., governor)
925		. . Including contacts which open and close motor circuit
926		. . Which controls a vacuum tube or solid-state device in motor circuit
927		. . Which varies resistance of motor circuit
928		. . Which controls position of commutator brushes
928.1		. Counter or back EMF (CEMF)
929		. Fluid/granular material flow rate, pressure, or level
930		. Load or torque
931		. . Electric generator or magnet as auxiliary load
932		. . With reverse torque (e.g., braking)
933		. Radiant energy responsive device
934		. Thermal condition
935		SPECIFIC APPLICATION:
936		. Food preparation equipment
937		. Hand tool

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Last Modified: 6 October 2000