Matches 51 - 100 out of 176 < 1 2 3 4 >
Match Document Document Title
4905300 Motor control and power systems and methods of operation thereof  
A pulsating D.C. voltage is developed by a rectifier 86 and is filtered by a capacitor 100 to facilitate application of a relatively smooth, enhanced D.C. voltage to a motor 106. The charged...
4885511 Drive control with overload protection for a drill device  
Drive control for a drilling device including a universal motor is arranged so that the total available mains voltage is applied when a fraction of the motor torque, available for the full work...
4803409 Acceleration signal corrected motor speed control system  
The speed of a motor supported on a supporting base the position of which is changed during operation of the motor is controlled by use of a detector for detecting the degree of angular...
4801855 Method and system for controlling chopper  
The magnitude of current change for the change of input voltage or for the change of speed of rotation of the shunt motor is utilized, i.e., the shunt characteristics are utilized, and the voltage...
4695778 Rotation phase control device  
A rotation phase control device which synchronizes the rotation phase of the rotor of a motor with a reference signal and which has a steady-state characteristic compensating circuit improves the...
4694228 Compensation circuit for control system providing pulse width modulated drive signal  
A closed-loop, temperature-controlled cooling system includes a Stirling cycle refrigerator driven by a dc motor, wherein the motor excitation derives from pulse width modulation. Temperature...
4567410 Capacitive article density monitor  
A capacitance article density monitor which is adjusted to have a zero voltage output when no articles are positioned adjacent a sensor and wherein the output of the circuit may be utilized...
4527104 Speed control apparatus for d.c. motor  
A speed control apparatus for a d.c. motor includes a bridge circuit which operates to detect a speed error signal. The speed error signal is applied to a Schmidt trigger circuit, an output of...
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...
4504769 Electrically-powered tool  
In an electrically-powered tool, the driving motor of the tool and a switching element for a phase control circuit for controlling the number of revolutions of the motor are connected in series....
4503370 Electronic clutch for electric tools of selectable speed  
An electronic clutch for a multispeed electric tool includes a voltage sensor having a D.C. voltage output proportional to the current absorbed by the tool's motor and dependent on the motor...
4500822 Digital capstan servo circuit  
A digital capstan servo circuit controls the rotation of a capstan motor used for sending a recording medium of a recording apparatus having a recording circuit for recording a plurality of pilot...
4495557 Switching controller directly operable from AC  
A high response motor controller is disclosed which operates directly from a multi-phase AC power line without a DC link. The controller directly converts power from a fixed frequency multi-phase...
4458186 Transistor control device for power transistor chopper  
A transistor control device in a power transistor chopper is arranged to charge a capacitor for feeding a base current to the chopper transistor with electrical energy stored in an impedance of a...
4456859 Sewing machine drive motor control system  
A speed-control circuit for a motor of the sewing machine is disclosed. The circuit includes a controller, thyristors for controlling the rotation of the motor in dependence upon the operation of...
4433370 Multiple phase chopper current limiting  
The current in each phase of a multiple phase chopper is sensed and compared to a reference overcurrent value. Any chopper phase reaching overcurrent and any chopper phase on for a longer period of...
4420713 Turn-off control means for an ac-to-dc electric power converter  
In the propulsion system of an electric locomotive, a-c wayside power is converted to direct current for the traction motors by a plurality of phase-controlled rectifying circuits having serially...
4412158 Speed control circuit for an electric power tool  
A method and apparatus for controlling the rotational speed of an electronically controlled power tool in both the forward and reverse direction. When the reversing switch is placed in the reverse...
4394724 Propulsion motor control apparatus and method  
A vehicle propulsion motor control apparatus includes a motor current regulating chopper apparatus and a free wheeling diode in the motor circuit. It is desired that the chopper apparatus not be...
4380724 Shunt field control apparatus and method  
A motor control is provided for a DC series motor operative with a chopper apparatus and including a thyristor switch to determine the field shunt operation of the motor. A voltage reversal that...
4371814 Infrared transmitter and control circuit  
An infrared transmitter and control circuit for a load such as a ceiling fan which is capable of starting and regulating the speed of the ceiling fan as well as reversing the direction of the...
4366531 Phase control for a multiple phase SCR chopper  
A multiple phase SCR chopper controller for establishing a normal phase relationship among the various SCR phases and for modifying the normal phase relationship for input signals for which the SCR...
4362976 Driving circuit for DC motor  
Disclosed is a DC motor drive circuit adapted to prevent thyristor commutation failure when a thyristor-controlled three-phase full-wave reversible bridge undergoes a transition in operating mode...
4358819 Electrical converter equipment having reduced harmonic circuits  
A static electrical converter equipment has a plurality of controllable converter bridges connected to a common a.c. supply source. Control pulse devices supply control pulses to the controllable...
4337509 Method and apparatus for controlling firing phases of thyristors  
A digital control system for controlling firing pulses supplied to thyristors for power conversion to desired phases, wherein data necessary for obtaining desired phase control signals is set in a...
RE30761 Three-phase DC motor having non-superimposed armature coils  
A coreless three-phase DC motor comprising a coil type armature formed with insulated windings. The armature is of a disc- or cylindrical-shape and is set rotatably against a field magnet provided...
4286315 Converter apparatus  
Converter apparatus including gate drive control of the stored energy type. Control logic arms the next controlled rectifier device to be gated a predetermined period of time following the gating...
4284934 Motor control apparatus with an improved thyristor chopper circuit  
A motor control apparatus to supply current from a D-C source to an electric motor has a thyristor chopper circuit, the duty factor of which is controlled depending on a current instruction signal....
4268781 DC Motor drive system  
An actual speed N of a DC motor and an armature current Ia are detected to detect the motor output N×Ia. The motor speed is changed so that the detected motor output may not exceed a predetermined...
4246522 Power converter with programmable commutation  
A power converter having improved efficiency and useful, for example, in the propulsion system of an electric vehicle. The power converter includes a dual chopper having an output level variable...
4236102 Control system for spool drive of magnetic tape apparatus  
A control system for a magnetic tape apparatus having two spool carriers driven by D.C. drive motors to control the current in one of the motors in order to maintain a uniform tape transport speed...
4233549 Speed and torque control for fractional horsepower motors  
Power control circuitry for supplying pulses of power from a power source to a fractional horsepower motor with a plurality of power pulses applied to the motor during each half cycle of the power...
4180767 Closed-loop regulating and overhauling load energy dissipating chopper type current control system for D.C. Motors  
A "chopper" type armature current control system for a D.C. motor when connected across the output of a rectifier, A.C. to D.C. type supply source that is characterized by having closed-loop...
4177412 Closed loop rotational speed control system having means for generating a PNM signal for an electric motor  
A PNM (pulse number modulation) signal is generated in response to a DC signal the magnitude of which is in proportion to the detected rotational speed of an electric motor to regulate a period of...
4172233 Electric vehicle traction motor control  
An electric vehicle traction motor control circuit includes a main thyristor in series with the motor armature. A second thyristor is connected in series with a commutating capacitor across the...
4168454 Circuit arrangement for controlling the speed of a D.C. motor  
A circuit arrangement for controlling the speed of a D.C. motor, and particularly a motor for operating dental instruments. The circuit arrangement comprises a reference signal generator, a...
4152758 Control logic for a phase controlled rectifier system  
Apparatus for providing firing signals to a phase controlled rectifier circuit at a time at which valves in the rectifier circuit are forward biased without the need for providing continuous firing...
4121141 D.C. motor speed control circuitry  
A closed loop D.C. motor speed control circuit compares tachometer feed-back signals proportional to the D.C. motor speed with a voltage reference representing the desired motor speed and generates...
4096422 Motor control system  
The duty cycle of the alternating current waveform applied to an electric motor is varied by varying the firing point of an SCR circuit. This firing point is varied by logic circuitry which...
4084119 Chopper control system  
A chopper control system for controlling the amount of power supplied from a DC power source to a load having inductance. The chopper control system comprises a chopper circuit for accomplishing...
4039915 D-C commutator-type dynamo electric machine with electronic control  
An electronic controlled switch, for example a bipolar thyristor, is included in the armature circuit between the brushes, conduction of the thyristor being controlled by a pulse source providing...
4011491 Motor speed control circuit  
A speed-controlling circuit for controlling the rotational speed of a D.C. electric motor in which the electric current is supplied to the D.C. motor through a switching circuit which is...
3980936 D.C. control circuits  
A d.c. control circuit includes a slew-rate limiting circuit interposed between a current sensing device which detects current in a load and a control circuit, for switching on and off a thyristor...
3914674 D.C. motor control having gating control of a full-wave reactifier system  
A D.C. motor is selectively connected to receive energizing power from a polyphase power source through a dual bridge rectifying system providing full-wave rectification and selectively operable to...
3903465 Chopper control system  
An improved chopper control system is proposed. In the system, a d.c. current supply to a d.c. motor is controlled through a chopper which is provided with a main thyristor and an auxiliary...
3902105 Thyristor motor control circuit  
In a thyristor speed control system for a battery-powered traction motor, motor operation is prevented if the thyristor is shorted or by-pass contacts in parallel with the thyristor are welded...
3896348 Circuit for supplying a dc load from an ac source through a rectifier  
An improvement A.C. a circuit for supplying a D.C. load from an A.C. source through an uncontrolled rectifier with a control element arranged between the output of the rectifier and D.C. load using...
3876919 Structure for and method of surface condition sensing and indicating and motor speed control  
The condition of a surface is sensed by cyclically moving two members having engaged surfaces relative to each other, driving the surfaces for only a portion of each cycle to set up a threshold...
3855520 CONTROL HAVING CONDUCTION LIMIT MEANS TO VARY DUTY CYCLE OF POWER SWITCH  
A pulse width modulation control for supplying variable width voltage pulses from a battery to a motor includes a power switch, an oscillator for providing a succession of triggering pulses, a...
3838324 SYSTEM FOR CONTROLLING THE ROTATIONAL SPEED OF A MICROMOTOR FOR USE IN MEDICAL INSTRUMENTS  
A system for controlling the rotational speed of a micromotor for use in medical instruments such as a dental handpiece comprises a first transistor connected in series between said motor and a...
Matches 51 - 100 out of 176 < 1 2 3 4 >