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4280085 Apparatus and method for providing a signal proportional to flux in an AC motor for control of motor drive current  
An apparatus and method for providing signals indicative of the magnitude and angular position of the DC motor flux of an AC induction motor is disclosed. The AC induction motor provides...
4272715 System for controlling torque of induction motors  
For the purpose of controlling the torque of a three phase induction motor a control system suitable to be operated by a computer is provided. A torque instruction, an angle of rotation, a flux...
4267499 Method and system for controlling induction motors  
The speed of an induction motor fed from a frequency converter is controlled by controlling the primary current by a primary current vector. To this end, a digital quantity corresponding to the...
4266432 Gyro motor control  
In order to eliminate the day-to-day gyro drift phenomena which result from interaction of the magnetic pole position of the synchronous motor typically used to drive the gyro and the gyro wheel,...
4263542 Method and circuit arrangement for controlling an asynchronous motor supplied from a static frequency changer  
Method for controlling the speed and torque of an asynchronous machine fed through a static frequency changer with impressed intermediate current link, a control variable for the frequency of the...
4259629 Control devices of induction motors  
The control device is provided with a frequency converter for feeding electric power to an induction motor and a compensating circuit for compensating for the delay of the response of the field...
4259630 AC Motor controller  
A controller for achieving quiet operation of an AC motor utilizes an arrement of force-commutated, controlled rectifiers that are gated in a manner that results in the motor windings being...
4255695 Method and apparatus for control of inverter synchronous machine drive system  
In an inverter-synchronous machine drive system subject to operator control, feedback control is employed to synchronize machine-inverter operation. A phase angle command signal, responsive to a...
4227138 Reversible variable frequency oscillator for smooth reversing of AC motor drives  
A variable speed ac motor drive such as a controlled current inverter drive with load angle control generates an inverter frequency command signal which at low speed has a large ripple component...
4143309 Turbomolecular pump drive method and apparatus  
A high vacuum turbomolecular pump is described incorporating a drive system which significantly reduces the amount of heat build-up therein. The pump includes an outer casing having an upper open...
4100466 Cold start system for motors  
Motors, particularly gyro motors, are started by initially operating the motors at a frequency lower than their normal operating frequency so as to draw a larger current and develop greater...
4060754 Electronic motor that includes an electronic waveform synthesizer and the synthesizer per se  
An electronic motor that accepts single-phase power and converts the same to polyphase power which is delivered to a polyphase winding of the machine. The electronic motor includes an electronic...
4054818 Solid state current source polyphase inverter induction motor drive  
A solid state, current source, polyphase inverter induction motor drive is disclosed wherein the current source is derived from a constant potential buss. Each side of the buss is connected to the...
4047083 Adjustable speed A-C motor drive with smooth transition between operational modes and with reduced harmonic distortion  
Alternating voltage for energizing an adjustable speed a-c motor is derived from unipolarity input voltage by means of electric power inverting apparatus comprising at least one pair of alternately...
4039910 Dynamoelectric machine  
A dynamolectric machine stator has a primary winding for single phase alternating current input and a secondary winding for polyphase alternating current to be supplied from output terminals. The...
4019116 Commutation circuit for a converter  
A commutation circuit for a converter is disclosed. The circuit comprises an intermediate DC link which is coupled at one end to the converter and which includes a smoothing choke. A DC controller...
4008428 Circuit arrangement with a number of frequency converters, particularly Y-connected direct frequency converters  
A circuit arrangement is disclosed having an odd number of Y-connected frequency converters. The control units of the frequency converters are associated with current regulators, all of which are...
4002958 AC output power control system  
An AC output power control system comprising turn-on means controlling at least three or three groups of switches operationally connected between a power source and a load in predetermined order,...
3886431 Synchronizing circuit having an infinite number of ratios  
An inverter apparatus for controlling thyristor means with a reference and a carrier wave form is disclosed including a variable frequency reference generator for the reference wave form and a...
3886430 Phase and frequency synchronizing circuit  
An inverter apparatus is disclosed for synchronizing a carrier wave form to a reference wave form to have a given frequency relation for controlling thyristor means. The carrier and reference...
3875483 POWER SUPPLY FOR REFRIGERATION UNITS  
An electronic power supply which derives power from a DC battery to operate the AC induction motor of a refrigeration compressor unit. The amplitude and frequency of the AC voltage developed by the...
3870945 INVERTER SYSTEM HAVING SMOOTH SWITCHING BETWEEN OPERATIONAL MODES  
In an inverter system for the conversion of direct current power to alternating current power of the type including an inverter circuit selectively operable in either a time ratio controlled (pulse...
3866702 Accelerator for car transmission system  
A battery driven car provided with an inverter supplying an induction motor which drives the wheels, has the speed of the motor and its torque controlled by the frequency and power output of the...
3864618 ELECTRO-MECHANICAL VIBRATORY DRIVE CONTROL  
A variable frequency electrical power supply circuit includes a power circuit that provides a drive signal to energize a load and a control circuit that controls application of the drive signal to...
3816808 CHANGING THE FREQUENCY OF A POLYPHASE ALTERNATING CURRENT SUPPLY AND APPARATUS THEREFOR  
A method of and an apparatus for controlling the frequency of a polyphase alternating current supply applied to a polyphase load. SCR's or triacs are connected in matrices between each supply phase...
3789290 VARIABLE SPEED MOTOR AND DRIVE CIRCUIT  
A firing circuit for use with a diode isolated, capacitor commutated inverter utilizes the operative state of the inverter for directing the firing or gating pulses to sequentially firable...
3781641 ADJUSTABLE FREQUENCY POWER SUPPLY OF THE INVERTER TYPE  
A power supply of the inverter type for controlling the operative condition of an alternating current load includes a power source, typically of the rectifier type, providing an output current. An...
3781646 CURRENT SUPPLY COMPRISING AN ASYMMETRIC RECTIFIER ARRANGEMENT  
Full-wave rectified current supply comprising a single thyristor the gate electrode of which is connected to an electronic control circuit, which supply is connected to a direct-current motor....
3767988 MOTOR CONTROL CIRCUIT AND THREE-PHASE GENERATOR WITH STATIONARY COMPONENTS  
An electrical three-phase generator and motor control circuit. The generator is made of three alike wave-generating units in cascade each generating a respective trapezoidal wave corresponding to a...
3757184 ALTERNATING CURRENT MOTOR SPEED CONTROL CIRCUIT  
An induction motor speed control circuit which creates sub-multiples of the power line frequency by selective switching of the line voltage to allow certain cycles representative of a bilateral...
3732473 INVERTER COMMUTING CAPACITOR CHARGE CONTROL CIRCUIT  
An inverter commuting capacitor is connected in shunt with a series combination of an inductor and a controlled rectifier to limit the transient time of the commuting capacitor during commutation....
3718851 MEANS RESPONSIVE TO AN OVERVOLTAGE CONDITION FOR GENERATING A FREQUENCY INCREASING CONTROL SIGNAL  
The d-c voltage of reversible d-c to a-c power conversion apparatus is continuously sensed and utilized to produce an overvoltage signal when and only when the d-c voltage is equal to or greater...
3710218 INDUCTION MOTOR SPEED CONTROL  
The speed of an AC induction motor is controlled by regulating the frequency of the voltage applied to the stator. An improved frequency conversion circuit reduces the power line frequency to a...
3707659 CHOPPER CONTROL APPARATUS HAVING A COMMON CONTROL PATH  
A vehicle includes a plurality of vehicle cars, one vehicle car of which provides a vehicle control signal for use by itself as well as for transmission over a single signal transmission path to...
3701001 THREE-PHASE INVERTER CONTROL CIRCUIT  
A three-stage shift register circuit, responsive to the output signals of a variable frequency oscillator, produces a repeating series of six equally spaced electrical timing signals. A...
3668489 FREQUENCY DOUBLER MOTOR DRIVE AND MOTOR  
A frequency doubler induction motor drive circuit supplied from a line frequency power source for driving a two-pole induction motor at 7,200 rpm. The drive circuit supplies a 120 Hz waveform to...
3667016 REGENERATIVE BRAKING CIRCUIT FOR INDUCTION MOTORS  
An induction motor is normally driven from a clock source acting through a power bridge inverter. Braking is accomplished by substituting a feedback signal for the clock signal. A tachometer in the...
3659169 MOTOR SPEED CONTROL USING A COUNTDOWN COUNTER  
The speed of a hysterisis induction motor is controlled by eliminating selected pulses from the alternating current supply by loading a count-down register at regular intervals with a binary...
3652924 ARRANGEMENT FOR CONTROLLING THE CURRENT OF AN AT LEAST TWO-PHASE LOAD WITH CONSTANT FREQUENCY SUPPLY VOLTAGE  
An arrangement for the operation of a polyphase load from an alternating current source through the control of triacs. One triac is connected in each phase of the source connected to the load. The...
3644721 APPARATUS AND METHOD FOR DIGITAL FREQUENCY ADDITION AND SUBTRACTION  
The digital frequency system of this invention provides an output signal comprised of pulses which have a frequency equal to the sum or difference of the frequencies of two input signals. Each of...
3621352 INVERTER-CONTROL SYSTEM FOR AC MOTOR WITH PULSE-LOCKED CLOSED LOOP FREQUENCY MULTIPLIER  
The invention is a closed loop pulse-locked frequency multiplier. A master pulse train is applied to a digital discriminator, the output of which is in turn applied to a voltage controlled...
3617836 CONTROL CIRCUIT FOR SYNCHRONOUS MOTOR  
A control circuit is disclosed herein for applying signals to an inductive load, such as the winding of a synchronous motor. The circuit includes means for producing essentially a square wave...
3611434 IMPROVED FREQUENCY MULTIPLYING ELECTRICAL CIRCUITS FOR MOTOR SPEED CONTROL  
An electric motor is fed through a rectifying circuit with a bypass circuit connected across the motor for removing the DC component of the rectified current so that the motor is fed with an AC...
3611087 FREQUENCY-CONTROLLED AC DRIVE  
As is well known, a six-phase thyristor circuit of a so-called cycloconverter provided with 36 thyristors allows an output frequency at the order of 15 to 20 c.p.s. to be produced with the network...
3609490 TWO PHASE MOTOR DRIVE CIRCUIT  
A circuit for providing base drive to the output stages of a square wave motor drive circuit. The output stage of a motor drive circuit comprises two output transistors. The collector current of...
3593082 AC MOTOR DRIVING MEANS  
AC motor driving means comprising a DC source, an inverter converting said DC to AC, a semiconductor switch element connected in parallel to the motor connected to the output terminal of the...
3571681 CONTROLLABLE SPEED MULTIPLE PHASE MOTOR  
A variable frequency oscillator drives a two-phase generator to provide quadrature components at a quarter of the oscillator frequency. These signals in phase quadrature are applied to respective...
3543114 DRIVE MEANS FOR 2-PHASE MOTOR  
3538405 PARALLEL ENERGIZATION CHANNELS WITH DC-TO-DC CONVERTER IN EACH CHANNEL  
3534240 APPARATUS FOR SYNCHRONIZING THE TURNING SPEEDS OF ALTERNATING CURRENT MOTORS