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| Number | Title | Issue Date |
| 7348757 | Circuit to improve motor phase current reconstruction via DC link Apparatus for reconstructing the phase currents of a multiphase load driven by a multiphase inverter fed by a DC link and controlled by a PWM controller, the apparatus including a sensor in the DC link, first and second sampling arrangements for sampling the current... | 03/25/2008 |
| 6762575 | Electronic rotor pointing with high angular resolution A laser level with a sensorless DC motor controller having a feedback sampling circuit connected in parallel with the coil to sense back EMF. An integrator provides a feedback signal from the sensed back EMF, which the amplified difference from a reference level is ... | 07/13/2004 |
| 6548977 | Motor tracking control system An electronic circuit and software control methodology tracks motor position in a motor drive system. High power consumption position transducers, such as inductive sensors or optical encoders, can be controlled in a variable active duty cycle mode to red... | 04/15/2003 |
| 5811946 | System and method for velocity control of a D.C. Motor A system and method is disclosed for feedback velocity control of a D.C. motor. The system includes a motor (30) which is represented by its circuit equivalent--a series combination of an inductance (32), a resistor (34) and a back EMF source (36). The dr... | 09/22/1998 |
| 5777449 | Torque ripple reduction using back-emf feedback Methods and apparatuses are provided to identify and extract a torque ripple signal found in the back-emf signal from an electric motor. The torque ripple signal is used in a feedback control loop to reduce the amount and effects of torque ripple in the m... | 07/07/1998 |
| 5632000 | Device for optimizing the speed control behavior of a subfractional horsepower motor A device for the optimizing of the speed control of an electric subfractional horsepower motor for dental instruments is provided wherein it is possible to operate the motor in any desired speed range. The device contains a first module for regulating the... | 05/20/1997 |
| 5497062 | Digital pulse-width modulated system for providing current to a load A digital process generates a pulse-width modulated (PWM) signal for providing current to a load. In one embodiment, an input signal is repeatedly sampled at times corresponding to edges of a reference square wave. The sampled values are used to produce a... | 03/05/1996 |
| 5375186 | Device for speed stabilization of a motor employing phase comparison An apparatus for stabilizing the speed of a motor has a phase comparator that identifies a phase difference between a reference signal and a speed signal. The apparatus acquires the speed of the motor and generates an output signal proportional to the ide... | 12/20/1994 |
| 5313549 | Procedure for filtering the speed feedback signal A procedure is disclosed for filtering the speed feedback signal in an elevator motor drive which is provided with a speed controller and in which the speed of rotation of the motor is measured. The procedure of the invention involves sampling the speed f... | 05/17/1994 |
| 5274735 | Electric shaver An electric shaver comprises: a current detecting circuit which detects load current of a motor; a microcomputer which samples the values detected by the current detecting circuit periodically to judge the size thereof, and the positive or negative result... | 12/28/1993 |
| 5046123 | Error signal detection circuit in a servo control device An error signal detection circuit in a servo control device comprises a reference signal generation circuit for selectively generating reference signals of different periods, each having a slope which changes from a reference value at a substantially cons... | 09/03/1991 |
| 4893067 | Direct current motor speed control The motor speed control circuit senses average back EMF as a measure of motor speed. The back EMF charges a capacitor circuit which accumulates charge and develops a voltage indicative of the motor speed. A sample and hold circuit may be used to sample th... | 01/09/1990 |
| 4866356 | Circuit for controlling the speed of a subfractional horsepower DC motor A circuit for controlling the speed of a subfractional horsepower DC motor has a driver stage with a switch that interrupts the motor current in repeated succession so that a pulse-like current is provided, and the motor EMF is sampled synchronously with ... | 09/12/1989 |
| 4851744 | Feedback circuitry for D.C. motor speed control A circuit for controlling the speed of a DC motor provides delay and sampling means in the feedback loop to delay the triggering of the SCRs driving the DC motor and measured the motor armature voltage during the period of the delay, thereby eliminating e... | 07/25/1989 |
| 4843288 | Phase locked motor control system for multiple disk drive units A motor control system and related method are provided for phase and frequency locked operation of multiple spindle motors in a computer disk drive environment or the like, for coupling two or more disk drive units together to provide expanded data storag... | 06/27/1989 |
| 4816723 | Variable speed motor control method and apparatus A motor control method and apparatus employing a speed control loop and a phase control loop, each of which receives a clock signal (F-- TACH) indicative of the motor's measured phase and rotational frequency, and a synchronizing clock signal (... | 03/28/1989 |
| 4804894 | Motor rotation servo control apparatus A motor rotation control apparatus employs a comb filter circuit operable to filter out a signal component and its higher harmonics. An error signal indicative of an error between actual and target conditions of rotation of the motor is applied to the com... | 02/14/1989 |
| 4804895 | Charge balancing current sampler for a digital motor control An analog current sensing circuit is controlled by a current loop microprocessor. An integrator circuit stores charge which is the integral of armature current in a motor. The output is read by the microprocessor and divided by a time value to determine a... | 02/14/1989 |
| 4749927 | Adaptive digitally controlled motor drive system and method A digitally controlled motor drive system using a pulse width modulated motor drive receives a desired motor velocity signal and an actual motor velocity signal and it provides a corresponding velocity error signal. The velocity error signal is adjusted i... | 06/07/1988 |
| 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 change is to be detected. The reference frequency signal, thro... | 03/29/1988 |
| 4727300 | Motor control method A signal representing the period between adjacent positive-going edges and the period between adjacent negative-going edges of a pulse train generated by a rotary encoder coupled coaxially to a motor is compared with a reference period signal for the moto... | 02/23/1988 |
| 4716535 | Speed detection apparatus A speed detection apparatus for detecting speed of electric equipment on the basis of a sampling interval so as to stably operate a variable speed control system connected thereto. The sampling interval is varied in accordance with an input current to be ... | 12/29/1987 |
| 4710825 | Disc recording system with speed control A system for recording information on an information recording disc such as a magnetic or optical disc. The recording system includes velocity control means for controlling the disc at a predetermined rotation velocity and synchronizing signal phase shift... | 12/01/1987 |
| 4694234 | Apparatus for compensating a quantization error An apparatus for compensating for a quantization error has a time detector circuit for detecting a time signal on the basis of the number of clock signals occurring within the period of such time signal, a quantization error detector circuit for generatin... | 09/15/1987 |
| 4668900 | Digital servo apparatus A digital servo apparatus according to the present invention latches a count output of a counter (11) for counting reference clock signals in response to output of a speed detecting pulse from a speed detecting pulse generator (10a) in a latch circuit (14... | 05/26/1987 |
| 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 plural command values; a current regulator for controlling ... | 04/28/1987 |
| 4636959 | Microprocessor controlled d.c. motor for controlling a postage meter In combination with a postage meter which includes a plurality of loads, a source of supply of motive power for driving the respective loads and instrumentalities for selectively coupling the source of motive power to the respective loads, there is provid... | 01/13/1987 |
| 4631681 | Microprocessor controlled d.c. motor and application therefor An improvement in combination with a postage meter including a rotary drum having a periphery adapted for feeding a sheet in a path of travel. The improvement comprises: a first device for sensing a time interval during which a sheet is linearly displaced... | 12/23/1986 |
| 4630210 | Microprocessor controlled d.c. motor for controlling a load Apparatus is provided for controlling the velocity of a portion of a load in accordance with a trapazoidal-shaped velocity versus time profile. The apparatus includes a d.c. motor having an output shaft for driving the load; instrumentalities for sensing ... | 12/16/1986 |
| 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 carrier wave and the position is detected by measuring the wid... | 12/09/1986 |
| 4598239 | Circuit for regulating the rpm and phase of a motor A timing signal has a value changing during its period and a frequency dependent on actual motor rpm. A reference signal has an average value indicating desired rpm and a superimposed sawtooth component used, after desired rpm is reached, to generate phas... | 07/01/1986 |
| 4595868 | Phase detector control for a servo system A phase detection control apparatus is disclosed for detecting any variable where the phase is discretely measured, as for example, in a motor having a tachometer of an optical type. The phase detection apparatus eliminates direction sensitivity and does ... | 06/17/1986 |
| 4563623 | Motor speed control apparatus A motor is controlled by pulse signals applied to the gates of thyristors in a thyristor switching circuit. The speed of the motor is detected by a speed detector, and the instantaneous speed of the motor is calculated on the basis of the current detectio... | 01/07/1986 |
| 4551661 | Driving apparatus for a recording medium A driving apparatus for a recording medium which includes a motor for driving a recording medium, a preset counter for counting either of a reference clock signal and a signal provided by multiplying a reproduced synchronizing signal, the preset counter b... | 11/05/1985 |
| 4541023 | Resolver with sequential frequency and phase correction Apparatus for adjusting the speed of an audio tape capstan to a speed such that an audio tone prerecorded on the tape corresponds to a reference frequency, the apparatus thereafter phase locking the frequency of the audio tone to the reference frequency. ... | 09/10/1985 |
| 4517501 | Rotation control system A rotation control system including speed control feedback automatic speed control apparatus for controlling the rotation speed of a rotator to a predetermined speed, feedback automatic phase control apparatus for controlling the rotation phase of the rot... | 05/14/1985 |
| 4511830 | Servo control apparatus A frequency-voltage converting system has a first sampler for sampling the input signal at a predetermined time interval, a second sampler for sampling the input signal after elapse of a predetermined time period from said predetermined sampling time, and... | 04/16/1985 |
| 4493015 | Circuit arrangement for determining the load current in a reversible d-c controller or chopper In a reversible d-c controller, a current transformer having two primary windings as current measuring sensors is provided for determining the load current. The primary windings are connected with opposite winding sense into two diagonally disposed bridge... | 01/08/1985 |
| 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 are controlled by pulse modulation and which can work in fou... | 06/12/1984 |
| 4431950 | Capstan drive system for high speed tape duplicator Apparatus and method for controlling the speed of a tape drive having an ingoing capstan and an outgoing capstan with a magnetic head therebetween. First and second phase lock loop servo-circuits for driving first and second dc motors which drive the ingo... | 02/14/1984 |
