Abstract: A particularly high level of performance in a sensorless, electronically commutated multiphase electric motor can be achieved, wherein for one full cycle at least, one motor phase is controlled in an asymmetrical manner relative to a further motor phase by controlling a commutation angle of one motor phase by reduction relative to a corresponding commutation angle of the other motor phase. Alternatively or in addition, according to the aforementioned method, at least one motor phase is asymmetrically controlled by reduction by self-reference for a full cycle, a commutation angle being controlled by reduction relative to a preceding or subsequent commutation angle or the size of the intermediate angles between two commutation angles being varied, the reduced commutation angle always being preceded or followed by a measurement angle within which the relevant motor phase is switched at zero current for detecting the rotor position by measuring the counter-electromotive force.

Abstract: An apparatus for controlling a rotational speed of a motor, coupled to a sensing unit capable of outputting a sensing signal. The apparatus includes a controlling unit, coupled to the sensing unit, for outputting a controlling signal according to the sensing signal and independently of the rotational speed of the motor. The controlling signal is a square wave and has a duty ratio that is determined by the sensing signal. The apparatus also includes a driving unit, coupled to the controlling unit, for outputting a driving signal to a motor rotor according to the duty ratio of the controlling signal. The driving signal also is a square wave. The rotational speed of the motor rotor is determined by the duty ratio of the driving signal.

Abstract: A fan motor driving circuit of the present invention comprises a device for detecting a power source voltage and outputting a voltage in proportion to a difference between the power source voltage and a predetermined rated voltage when the power source voltage is greater than the rated voltage. The driving circuit also includes a device for controlling a rotary speed of a fan motor to a predetermined value by automatically varying a first signal input to a conducting current generating circuit for determining the rotary speed of the fan motor according to an output voltage of the power source voltage detecting means when the power source voltage is greater than a predetermined value.

Abstract: A speed control circuit of a direct current motor comprises a switching regulator IC 10. The switching regulator IC 10 is composed of a reference voltage generator 12 which generates a reference voltage of 5V, a first operational amplifier OP1, a second operational amplifier OP2, a third operational amplifier OP3, a triangular wave generator 14 which generates a triangular wave, and a transistor TR1. The speed control circuit is constructed using a general switching regulator IC; therefore, it is possible to cheaply and readily manufacture the speed control circuit of the direct current motor.

Abstract: It is an object of the present invention to provide a steering control system which can be used with a plurality of control modes, thereby reducing the cost. A first control unit of an electric power-steering system detects a reference current i.sub.REF on the basis of a steering torque T detected by a steering torque detecting device S.sub.2 ; searches a gain K.sub.1 on the basis of a vehicle speed v detected by a vehicle speed detecting device, and carries out a feedback control, so that an actual current i of an electric motor detected by a current detecting device is equal to K.sub.1 .times.i.sub.REF. A second control unit added to the first control unit changes the characteristic of the electric power-steering system by changing the steering torque T and the vehicle speed v, to output the changed steering torque T and vehicle speed v to the first control unit.

Abstract: Switching and propagation delays in generating a PWM control signal by a circuit that generally includes an error amplifier, a sawtooth oscillator and a comparator for comparing the error signal with the sawtooth signal, is compensated by generating a second sawtooth signal synchronous with the master sawtooth signal but having a reduced discharge time and by applying the second synchronous sawtooth signal to the respective input of the PWM comparator.

Abstract: A brushless dc motor unit has 3-phase armature windings, a permanent-magnet rotor, a dc power supply having a motor drive voltage and a midpoint voltage that is one half of the motor drive voltage, and an electronic commutation circuit. Back emf voltages at armature winding terminals are individually delayed by less than 90.degree. and the delayed voltages are individually provided to the positive input terminals of voltage comparators. To the negative input terminals of the comparators is commonly provided a sawtooth-wave comparator reference voltage having a frequency proportional to a current rotor speed and an amplitude whose center voltage is the midpoint voltage. Outputs of the comparators cause a control circuit to transmit signals to control the electronic commutation circuit so as to provide 3-phase dc power to the armature windings.

Abstract: For enabling discrimination of whether or not a blower motor is in a locked state to be conducted promptly and reliably irrespective of the motor speed, a blower system comprises a discrimination circuit for discriminating whether or not the blower motor is in a locked state based on change in the position of the rotor of the motor, and the discriminating time period between motor locking and output of a discrimination signal is determined to be shorter for a higher set rotational speed of the motor in response to the speed setting operation of a motor speed setting device.

Abstract: 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 identified phase difference. A controller receives the output signal. A control circuit for the motor is connected to the controller. The phase comparator comprises a sample-and-hold element, a sampling pulse shaper that is connected thereto and is input with the speed signal, a pulse shaper input with the reference signal, and a signal generator connected to the output of the pulse shaper and to the input of the sample-and-hold element.

Abstract: A solid state DC power control circuit to efficiently use DC battery power without the normally associated energy waste which includes an input control signal, amplifying and conditioning circuit (133), a triangular waveform generator circuit (131), a comparator circuit (135), an inverting MOSFET (metal oxide semiconductor field effect transistor) circuit (137), and a plurality of power MOSFET devices (42), which together combine to translate a typical variable resistance control input into a voltage level and condition it suitably to be compared with a known triangular waveform thereby creating a pulse width modulated signal whose pulse widths correspond in duration to the relative percent "on" or "off" of the control input signal and which regulates a plurality of parallel MOSFET devices (42) which together share the load of an external DC power drain circuit (143).

Abstract: In order to drive the stepper motor of a floppy disk drive with practically constant current in the face of fluctuations in supply voltage fed from a host system, a power control pulse generator circuit is provided which produces a series of power control pulses having a duty ratio dependent upon fluctuating supply voltage. The power control pulses are used for interrupting the excitation of the stepper motor windings during track seek operation. The power control pulses are generated by first repeatedly counting clock pulses from the host system to a predetermined number to provide periodically varying digital data, then translating the digital data into a triangular wave having an amplitude dependent upon the supply voltage, and then comparing the triangular wave with a reference voltage.

Abstract: In a preferred embodiment, a high-frequency, pulse-width-modulated, power-transistor, DC motor speed controller having current limiting in both drive and regenerative modes, essentially constant ramping rates regardless of whether or not the operator switches to neutral before changing direction, a simple sequencer which controls the timing of four functions--both drive and regenerative current measuring circuits and both drive and regenerative transistors, a highly effective transistor filter capacitor arrangement, and circuitry in which the level of regenerative current is used as an input to control the current under which the direction relays switch.

Abstract: A solid state DC power control circuit to efficiently use DC battery power without the normally associated energy waste which includes an input control signal filtering, amplifying, and conditioning circuit (133), a triangular waveform generator circuit (131), a comparator circuit (135), an inverting MOSFET (metal oxide semiconductor field effect transistor) circuit (137), and a plurality of power MOSFET devices (42), which together combine to translate a typical variable resistance control input into a voltage level and condition it suitably to be compared with a known triangular waveform thereby creating a pulse width modulated signal whose pulse widths correspond in duration to the relative percent "on" or "off" of the control input signal and which regulates a plurality of parallel MOSFET devices (42) which together share the load of an external DC power drain circuit (143).

Abstract: A method is disclosed for the low-loss regulation of a d.c. motor without commutator and of a semiconductor circuit in which, during a commutation phase at reduced motor power or rpm as given by a position indicator, the end transistors or one end transistor initially operates temporarily as a switch and thereafter temporarily as an analog amplifier element. During the analog period, a current is available which changes slowly according to a ramp function.

Abstract: 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 constant gradient, an error detection timing generation circuit for generating timing of detection of an error signal of an object of control, an error signal detection circuit for generating an error signal by detecting the value of a reference signal generated by the reference signal generation circuit at a timing provided by the error detection timing generation circuit, and a slope varying circuit for varying the slope of the reference signal in accordance with the period of the reference signal.

Abstract: In a power supply apparatus for driving a DC motor of a car cassette player, there is provided a switching regulator circuit for regulating a DC (direct current) input voltage to produce a desired DC output voltage; a motor driving circuit for driving a motor by receiving the DC output voltage of the switching regulator circuit; a sensor element for sensing a speed of the motor to output a sensor signal; a motor speed judging circuit for comprising a sensor signal from the sensor element with a reference signal to produce a judgement signal; and, a control voltage generating circuit for producing a control voltage based upon the judgement signal of the motor speed judgement circuit, whereby the DC output voltage of the switching regulator circuit is controlled in response to the control voltage.

Abstract: A solid state DC power control circuit to efficiently use DC battery power without the normally associated energy waste which includes an input control signal filtering, amplifying, and conditioning circuit, a triangular waveform generator circuit, a comparator circuit, an inverting MOSFET (metal oxide semiconductor field effect transistor) circuit, and a plurality of power MOSFET devices, which together combine to translate a typical variable resistance control input into a voltage level and condition it suitably to be compared with a known triangular waveform thereby creating a pulse width modulated signal whose pulse widths correspond in duration to the relative percent "on" or "off" of the control input signal and which regulates a plurality of parallel MdOSFET device which together share the load of an external DC motor circuit.

Abstract: A control circuit for maintaining power output of a motor, irrespective of amplitude changes in line voltage. The output of an amplifier is indicative of the line voltage. A ramp generator generates a ramp voltage which is consistent and repetitive, irrespective of changes in the line voltage. A comparison is made between the ramp voltage and the amplifier output, causing a triac to fire when the two are equal. The equalization point is a point at which sufficient power can be derived from the remainder of the line voltage to assure consistent and repetitive operation.

Abstract: A motor control circuit measures the motor voltage to determine actual motor speed. This speed voltage is the sum of the back emf and armature loses. The control circuit receives a reference voltage proportional to the desired motor speed and a further signal voltage indicative of the motor armature losses. These three voltages are combined to provide a first error signal representing the difference between the reference voltage and the motor back emf. This error signal is substractively combined with a signal representative of the motor power to produce a control signal for a modulator circuit which in turn controls a semiconductor switch in series with the motor.

Abstract: The present invention is directed to a motor rotation speed controlling apparatus including a comparator, a detecting circuit for detecting a feedback signal of a motor, a motor driving transistor, and a circuit for changing the level of a constant voltage fed to the comparator. The comparator compares a saw-tooth voltage with a constant voltage and outputs a signal which has a duty cycle corresponding to the result of the comparison. The motor driving transistor drives the motor in response to the output signal from the comparator. To change the duty cycle of the output signal from the comparator, a circuit is used that changes the level of the constant voltage in response to a feedback signal detected by the detecting circuit.

Abstract: In a circuit arrangement for the timed control of semiconductor switches (1-4) to each of which a freerunning diode (D1-D4) is connected in parallel and which are arranged in branches of a bridge, an ohmic-inductive load (5) of low loss power which lies in the diagonals of the bridge is to be acted on by a controlled average current value. For this purpose two semiconductor switches (for instance 1, 4) lying diagonally opposite each other in the bridge are closed in a current-application phase while in the following freerunning phase a freerunning current flows through the load. For the reduction of the loss power, at the start of the freerunning phase only one (1) of the two diagonally opposite semiconductors (1,4) is opened and a semiconductor switch (3) which lies in the bridge alongside the conductive semiconductor switch (4) is then closed.

Abstract: A motor speed control apparatus includes a ladder resistor circuit, a reference signal generator, and a comparator. The ladder resistor circuit selectively receives a voltage signal having a predetermined amplitude at a plurality of nodes. The ladder resistor circuit arranged to change an output voltage value thereof in accordance with a voltage application position. The level of the reference signal generator is periodically changed. The comparator compares a voltage value of the reference signal with an output voltage value of the ladder resistor circuit and outputs a pulse output having a variable pulse width on the basis of a comparison result. A motor speed is controlled on the basis of the pulse output.

Abstract: In a motor speed controll apparatus for a DC motor, there are provided a frequency signal generating circuit for outputting a signal at a time period corresponding to a rotation speed of a motor, a sawtooth wave output circuit for outputting a sawtooth wave, the voltage of which increases in a constant time-constant at said time period, a holding circuit for holding a substantially peak voltage of said sawtooth wave as a signal voltage corresponding to the rotation speed of the motor, a differential amplifier circuit for comparing said signal voltage with a speed setting voltage and for outputting a speed control signal in accordance with a difference in this comparison, said speed control signal being supplied to a motor drive apparatus, an amplifier circuit interposed between the output of said holding circuit and input of said differential amplifier circuit, and an operation control circuit for controlling said amplifier circuit to an operative mode and a non-operative mode selectively, the motor being dri

Abstract: 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 storage capability. The control system comprises a hybrid digital and analog network for producing a pulse width modulated control signal to control a disk drive spindle motor in a manner achieving frequency and phase locked relation with a reference signal. Multiple spindle motors are similarly driven in relation with the same reference signal, whereby the spindle motors are frequency and phase locked with respect to each other to permit, for example, parallel data transfer among the multiple disk drive units.

Abstract: A DC power controller for controlling the rate at which direct current is furnished to a load. A signal generator provides a periodic signal having a first value during a first portion of each period and a second value during a second portion of the period. A switch such as a power MOSFET enables direct current from the source to flow through the load during the time the signal has one of said values and prevents the current from flowing during the time the signal has the other value. A control is manually operable to vary the relative durations of the first and second portions of each period and thereby control the rate at which electric power is furnished to the load. A plurality of MOSFETS may be arranged in parallel if the load draws more current than one MOSFET can safely switch. Surge and back EMF protection are provided for inductive or variable resistance loads.

Abstract: A current limiting control circuit for a d.c. motor, wherein compensation is provided for the inherent voltage drop across the armature of the d.c. motor with a first dedicated amplifier, while a second dedicated amplifier provides current limit control. In providing a separate and dedicated amplifier for the current limiting function, the limitations inherent in the current/resistance compensation circuit, such as lag in response time, are avoided.

Abstract: An electronic control for regulating the operation of a two-speed motor in a heat transfer system such as a heat pump or air conditioner. The control receives high and low demand signals from a thermostat and a motor unit operates at high and low speeds in response to, respectively, high and low speed signals. The control includes an initial timer, high and low speed operators, and a speed change delay. The initial timer detects the occurrence of a demand signal from the thermostat, counts a predetermined period of time, and responsively issues an initial timing completion signal. The high and low speed operators detect the timing completion signal as well as either a high or low thermostat demand signal. One of the operators then responsively issues either a high or low speed signal to the motor unit. The motor unit accordingly operates at a high or low speed. The speed change delay detects the change in a thermostat demand signal from a high to a low state or a low to a high state.

Abstract: There is provided a continuous flow type homogenizer. The homogenizer comprises, a tubular container having at upper end thereof an inlet for introducing tissue to be homogenized and at lower end thereof an outlet for discharging the homogenized tissue, a pestle disposed freely rotatable in the tubular container with a clearance defined between the inner surface of the tubular container and the peripheral surface of the pestle, a rotation shaft driving means connected to a rotation shaft of the pestle, a speed setting means for setting the rotation speed of the pestle, and a speed controlling means for controlling the speed of the rotation shaft with a predetermined speed gradient with respect to a speed value set by the speed setting means.

Abstract: A digital servo system comprising source means of a clock signal, counter means, latch means which latches a predetermined lower bits of the output of the counter means, means for obtaining a servo control output in response to the latch means, and sequencer means which is applied with a digital data of which the pulse interval or the phase is processed, and controls passing or nonpassing of the clock signal to the counter means in response to the digital data and obtains a latch pulse for the latch device.