Matches 251 - 300 out of 385 < 1 2 3 4 5 6 7 8 >
Match Document Document Title
4734628 Electrically commutated, variable speed compressor control system  
A compressor speed control arrangement with provision for selecting compressor speed in view of changes in room ambient temperature, detecting a feedback signal indicative of compressor speed,...
4734630 Method and apparatus for phase comparison adapted to produce an error signal against an input signal having a relatively wide range of phase and frequency variation  
Method and system for phase comparison which uses a ramp-form signal generated from a reference frequency signal and a sampling pulse train signal synchronized with an input signal whose phase...
4733146 Energy recovery system for cyclic drives  
A system is disclosed for recovering and storing the energy generated by an electrical motor during deceleration so as to be available for use when the motor is subsequently accelerated. The system...
4728869 Pulsewidth modulated pressure control system for chemical vapor deposition apparatus  
A low pressure control system for chemical vapor deposition (CVD) apparatus, including a vacuum pressure chamber and an exhaust pump, is provided by a vacuum pump DC motor which is supplied power...
4705997 Bidirectional motor drive circuit  
A drive circuit is provided for a bidirectional DC inductive motor, as may be used for automotive window wipers and the like. Four power MOSFETS are connected in an H-bridge configuration with the...
4700117 Centrifuge overspeed protection and imbalance detection system  
A centrifuge overspeed protection and imbalance detection system is structured to provide a method for detecting rotor imbalance and rotor overspeed. The system has a single transducer to provide...
4698565 Hoist with overload safety protection  
The hoist, lifting apparatus or the like of our invention comprises at least one hoist motor, a protective controller for the hoist motor, and an overload safety device operating on the protective...
4684863 Semiconductor wafer boat loader control system  
A soft landing cantilever boat loader for loading semiconductor wafer carrying boats into a furnace process tube includes a loading station having one or more loading assemblies, an automatically...
4675588 Electrical power control apparatus  
An electrical power control apparatus in which power to a load is shared between a plurality of power semiconductors, only one of which is shown. Each power semiconductor forms part of a separate...
4667480 Method and apparatus for controlling an electrically driven automotive air conditioner  
A control system for an electrically driven variable capacity automotive air conditioning system affords the passenger maximum comfort control without overloading an electrically commutated motor...
4661750 Device for controlling DC motor  
A device for controlling a DC motor to establish a target speed, comprising: a speed setter for providing plural command values of speed of the DC motor; a speed selector for selecting one of the...
4656402 Electric motor control apparatus  
In the present invention, in an electric motor control apparatus wherein a load current modulated in a pulse form and flowing in an electric motor is detected, and the load current is controlled by...
4651070 Transit vehicle start-up propulsion motor control apparatus and method  
Current regulation is provided for the propulsion motor of a vehicle operative with a track signal block control signal having a known frequency characteristic, by modulation of a selected group of...
4638225 Method and apparatus therefor in motor speed control  
A pulse width control apparatus and method for controlling motor speed wherein the number of pulses relating to more speed feedback data is counted so as to control the speed of the motor in...
4635927 Low power treadmill  
The specification discloses an exercise treadmill for diagnostic and therapeutic purposes incorporating an improved drive and control system. High efficiency at low rpm is effectuated through the...
4628314 Method and apparatus for detecting position and velocity of moving body  
A method for detecting the position and the velocity by using an encoder mounted directly on a moving body wherein original signals of the encoder are pulse-width modulated by using a sampling...
4628460 Microprocessor controlled phase shifter  
A new method and apparatus for controlling the conversion of AC electrical energy into DC electrical energy. A microprocessor control system is operatively connected to an AC source and to a...
4625156 Control device  
A device for controlling plural loads with phase locked loop control method by means of reference signals of different phases in order to avoid peak in electric power consumption.
4623827 Device for controlling motor rotation speed  
A motor speed control device for variably controlling the rotation speed of a motor over a wide range. The control device performs proportional integration (PI) using an actual motor speed and a...
4622500 Electric motor controller  
Apparatus is provided comprising a motor having a current applied therethrough. The speed of the motor is a function of the current passing through the motor. An error signal is produced...
4617675 Digital PWMed pulse generator  
Plural series of digital pattern data are determined by PWMing a sine wave by a triangular wave and further classified into each series by the number of triangles included within a half cycle of...
4611682 Motor-driven power steering system  
An improved electric power steering system is disclosed. The system includes an electric motor as a driving device. Input system torque, motor current flow and motor temperature are detected and...
4599548 PWM controller for an electrical load  
A PWM controller for an electrical utilizes a dual differential input topology comprising two input comparators deriving a proportional reference from two potentiometers for providing a variable...
4581565 H-bridge power amplifier and method for controlling the same  
An improved H-bridge power amplifier for controllably driving a dc motor is presented. The motor is connected in the center of the H-bridge in conventional manner. The H-bridge includes a current...
4580083 Chopper controller for a D.C. motor  
A chopper controller for a D.C. motor controls currents flowing in an armature winding and a field winding of the D.C. motor by controlling an armature chopper and a field chopper in accordance...
4567411 High frequency pulse width modulation  
A counter (24) increments several times during the duty cycle of a microprocessor (10), and a comparator (30) connected to both outputs a High signal when the microprocessor output exceeds the...
4562549 Digital player using a pulse width detector  
In a pulse width detector circuit, a high-level pulse width and a low-level pulse width of a digital signal derived by slicing an analog signal reproduced from a disc at a predetermined level are...
4562393 Modulation scheme for PWM-type amplifiers or motors  
In a motor control system for a DC motor, a modulation circuit provides a plurality of pulse width modulated signals to control the current applied to the motor. The motor is coupled to a current...
4523134 Control system for DC motors  
In a DC motor control system, switching element driving circuits are connected to respective base circuits of four switching elements arranged to form a bridge circuit which has a DC motor...
4518901 Motor control apparatus  
A motor control apparatus for driving and controlling a motor, in which a signal frequency proportional to a rotation number of the motor is converted into a d.c. voltage by a frequency/voltage...
4516060 Digital motor speed control  
A motor speed control circuit produces indexing pulses during each revolution of the motor. Each indexing pulse triggers the production of a predetermined pattern of timing pulses. The timing...
4508999 Short circuit protection apparatus  
An apparatus (10) for controlling the supply of power from a power source (12) to a motor (14,14'). The apparatus (10) has a controllable switch (20,20') for coupling power to the motor (14,14')...
4500820 Protective control apparatus for electrical vehicle  
A control apparatus for electric vehicles by using a chopper circuit which turns on or off a d-c drive motor responsive to the instruction of a microcomputer. The control apparatus of the present...
4491904 Chopper control apparatus  
A chopper control apparatus comprises a chopper connected between a d.c. power supply source and a load, and a computer for performing an arithmetic operation for controlling the duty factor of the...
4482850 Control circuit for DC capstan motor  
A control circuit is used during slow or stop-motion playback operation of a video tape device to drive video tape intermittently. In order to avoid errors in the stopping position of the tape, a...
4480216 Motor driving circuits  
A motor driving circuit comprising a pulse generating circuit for generating plural types of pulse trains, a modulation pulse generating circuit connected to the pulse generating circuit, a...
4471276 Electric motor speed controller and method  
An electric motor speed controller circuit which comprises at least one power transistor in series between the motor and a power supply to form a power circuit such that current flows between the...
4454573 Current regulator circuit  
A digital current regulator circuit, especially useful for a DC motor, is described which is fed directly, i.e., without power transformers, from the AC mains, via power transistors (T1-T4) that...
4454459 Method of controlling the speed of a drill, hammer-drill, or rotary hammer and apparatus therefor  
The invention is directed to a method and apparatus for controlling the speed of an electronically controlled drill, hammer-drill or rotary hammer driven by an electrical motor wherein the...
4427930 Electric vehicle current regulator  
A current regulator for a dc electric traction motor propelled vehicle, implemented using a microcomputer, incorporates an accelerator response characteristics of an accelerator in an internal...
4423362 Electric vehicle current regulating system  
A control system for a separately excited DC electric traction motor in an electrically powered vehicle incorporates a plurality of current limit functions designed to protect both the motor and...
4423498 Control apparatus for a recording medium drive motor in a digital information reproducing apparatus  
A digital audio disc (DAD) reproducing apparatus comprises pulse width detection and pulse width-to-voltage conversion means for detecting a signal having a predetermined pulse width such as a...
4413212 Motor control apparatus  
There is provided a digitized motor control apparatus which is capable of digitally effecting all the functions of the motor control apparatus except those involved in energy conversion.
4386302 Control device for a multispeed motor  
A control device for multispeed motor having a first circuit for providing a detection signal whose period corresponds to a rotation speed of the motor, a trigger pulse generator connected to the...
4384241 Sewing machine drive  
A sewing machine drive having a mains rectifier (1) which, via a chopper (2) operating at a relatively high frequency, supplies direct current pulses to the driving motor (3). The duty ratio of...
4383245 Digital servomotor drive apparatus  
An apparatus for converting digital signals into analog pulse width modulated signals without a D/A Converter includes an up-down counter, programmed by the digital signal, which provides a signal...
4381479 Electric motor chopper control apparatus and method  
A programmed microprocessor controller chopper apparatus for an electric motor is responsive to an operating condition of the chopper such as at least one of the commutation capacitor charge...
4380723 Digital velocity servo  
A servo circuit for electronically controlling the operation of an electric motor is disclosed. The rotational frequency of the motor is converted into a varying frequency waveform by a tachometer....
4371819 Pulse width modulation speed control  
A pulse width modulation (PWM) speed control for a DC electric motor includes an encoder for providing encoder pulses in reponse to incremental rotation of a shaft driven by the motor. A timer...
4360767 Motor speed control apparatus  
A motor speed control apparatus includes a motor, a frequency generator for generating a detective frequency signal, the frequency of which is proportional to the motor speed, and a control signal...
Matches 251 - 300 out of 385 < 1 2 3 4 5 6 7 8 >