Abstract: An actual detected current value and a target voltage value of an electric motor are subjected to a low-pass filter process, and amounts of change per time in the filtered actual current value and the filtered target voltage value are calculated. If the amount of change in the actual current value on the increase side is greater than a criterion value and the amount of change in the target voltage value on the decrease side is greater than a criterion value, it is judged that the stroke end has been reached. Then, the upper limit value of the target current value is set at the actual current value obtained in the immediately previous cycle of the feedback control, so as to prevent generation of unnecessary torque.

Abstract: A fan motor controller comprised of a power supply unit, three driving circuits., three power output circuits, a microprocessor, a voltage raising and compensation circuit, a Back-EMF sensing circuit, a current-limit protection circuit, and a speed control circuit. The fan motor controller eliminates the use of a Hall sensor, enables the field effect power transistor of the works in full conduction of each power output circuit to work in full conduction so as to lower the temperature.

Abstract: An apparatus and method for controlling a motor, which are capable of accurately controlling a speed of the motor regardless of whether an error occurs in a clock circuit of the apparatus. It is possible to accurately control a speed of the motor regardless of a time error of the clock circuit, which occurs due to a use condition or long-term use, by driving the motor according to an input speed signal, detecting a driving waveform of the driven motor, synchronizing the detected driving waveform with the speed signal, and controlling the speed of the motor.

Abstract: The present invention provides a control device capable of improving hysteresis characteristics of a voice coil motor (31) and attaining a suitable lens position without complicating the structure of the control device. As solving means of the invention, a voice coil motor control device (30) includes a driving current control part (34) that controls a driving current supplied to the voice coil motor (31) in accordance with a driving pulse subjected to pulse width modulation, and a driving pulse control part (32) that divides a drive period of the voice coil motor (31) into a movement period and a holding period, and controls the driving pulse by changing the duty ratio of the driving pulse during the movement period in accordance with a duty setting value and fixing the duty ratio of the driving pulse during the holding period to the duty setting value.

Abstract: An electrically driven fan arrangement, suitable for energy-conserving installations, includes a fan, an electric motor (110) serving to drive the fan, and associated control apparatus, namely: a sensing apparatus (140) for sensing a volumetric air flow rate (125) generated by the fan (120) and for generating a measured volumetric air flow value (Vmess), and a volumetric flow rate control arrangement (160) for automatically controlling the volumetric air flow rate (125) generated by the fan (120) to a predetermined target volumetric air flow value (V_s). The volumetric flow rate control arrangement (160) is configured to generate a target rotation speed value (N_s) for the electric motor (110). A rotation speed controller (170), which automatically controls the rotation speed of the electric motor (110) to the target rotation speed rate (N_s) generated by the volumetric flow rate control arrangement (160), is also provided.

Abstract: The invention relates to an electric power tool having a control and/or regulating device for an electric motor. It is provided that the control and/or regulating device (4) is assigned an electronic memory element (5) for at least one operating state of the electric motor (1).

Abstract: In a motor driving apparatus, a control unit detects a rotation frequency of a motor to be driven and generates a control voltage Vcnt in a manner such that the rotation frequency thereof is brought close to a desired rotation frequency. A clamping circuit sets an upper limit Vcu and a lower limit Vcl of the control voltage Vcnt. A drive unit drives the motor based on the control voltage Vcnt generated by the control unit. A start circuit fixes the control voltage Vcnt to a predetermined initial voltage Vinit at the start of driving the motor.

Abstract: One embodiment of the invention relates to a control system. A control system includes a controller configured to generate a drive signal as a function of a comparison between a first control signal and a second control signal, wherein the first control signal differs from the second control signal. A switching device is configured to generate an output control signal having a duty cycle that is a function of the drive signal. Other systems and methods are also disclosed.

Abstract: A drive circuit drives a motor in a mode selected from first and second modes. A drive unit operates in response to a control signal received from a signal generation unit to control how the motor should rotate. The control signal is applied to drive the motor in the first mode. The signal generation unit receives a select signal indicating one of the first and second modes. When the select signal indicates the first mode, the signal generation unit outputs an input signal as the control signal. When the select signal indicates the second mode, the signal generation unit generates the control signal in accordance with the input signal. A motor drive circuit capable of driving a motor regardless of a difference between input modes in type, and electronics equipped with, can thus be obtained.

Abstract: A method for cadence detection in a sequence of video fields is based on at least a search for cadence patterns in a sequence of bits representative of the motion in at least a part of the field from one field to another in the field sequence. The signaling of field skip and/or field repeat commands as applied to the fields in the field sequence is considered during the cadence detection operation so as to field skips and repeats.

Abstract: A driving circuit of an AC fan motor has an AC to DC converter, a current detecting unit, a step-down divider, a motor driving unit, two windings each having many coils and a harmonic wave elimination unit. The AC to DC converter converts AC power to high voltage DC power. The motor driving unit is connected to the step-down divider to obtain low voltage DC power to operate. The two windings are directly connected to the AC to DC converter through the current wave detect unit to obtain the high voltage DC power. Therefore, the current wave detecting unit can response current changes of windings and then an operator can simulate present current wave of the windings to determine the present operating status of the AC fan motor.

Abstract: A circuit for indirectly measuring a sign of a current flowing in an inverter stage coupled to a phase of a motor or indirectly measuring the sign of the voltage induced by a counter Electromotive Force (EMF) in a coil of the phase of the motor, the inverter stage being connected between a power supply and the ground. The circuit includes a gate driver circuit coupled to the inverter stage for alternatively connecting the phase of the motor to the power supply and to ground, the gate driver circuit having a current sign detection circuit, wherein the current sign detection circuit senses the sign of the current flowing in the inverter stage, or the sign of the counter EMF for controlling the commutation of switches in the inverter stage.

Abstract: An adjustment system is disclosed for adjusting a proportional, integral, derivative controller in a limited rotation motor system. The adjustment system includes a first transform unit, a second transform unit, a model identification unit, and a PID adjustment unit. The first transform unit is for receiving a first digital signal that is representative of a motor control signal, and is for providing a first frequency domain sequence that is representative of a frequency domain representation of the motor control signal. The second transform unit is for receiving a second digital signal that is representative of a position detection signal, and is for providing a second frequency domain sequence that is representative of a frequency domain representation of the position detection signal. The model identification unit is for identifying a representation of a ratio of the first and second frequency domain sequences.

Abstract: Disclosed are systems and methods for receiving and manipulating the travel of a sheet material, such as paper, from a device such as an imaging device. One embodiment of a system can be implemented as a system for handling a sheet material including a flipper device that has a shaft for accelerating a sheet material, such as paper. The flipper device also has a drive system for causing the shaft to rotate. A drive system is also provided that has a direct current motor configured to drive the shaft.

Abstract: Amperage control of a power tool motor is provided by pulse width modulation of current from a power supply. The pulse width modulation may be varied according to the determined motor current and measured power supply voltage. The power supply preferably includes a battery, such a lithium ion or nickel cadmium.

Abstract: An eletrical device derives power from an incoming power source to produce output plower to drive the device. The device includes circuitry that determines at lehst one characteristic of the incoming power source, and adjusts the output power used to drive the device based on the characteristic or characteristics of the incoming power source.

Abstract: A speed control apparatus includes a speed control part 12 for generating a source current command based on a difference between a speed command of a motor 4 and speed detection in which a speed of the motor 4 for driving a load 2 is detected, a notch filter 14 which can break a notch frequency resulting in a predetermined frequency selected among continuous frequency band widths and also generates a compensating current command in which the notch frequency is eliminated from the source current command signal, a notch filter adaptive part 16 for selecting the notch frequency so that the compensating current command in which a sustained vibration frequency component of the source current command is eliminated is generated from the notch filter 14, a subtracter 103 for generating an elimination portion current command resulting in a difference between the source current command and the compensating current command, and an adder 109 for adding the compensating current command and the elimination portion current

Abstract: A system and method for measuring fluid flow rate in a system where fluid is pumped, such as a gas monitoring instrument where gas is pumped from a space such as a room or enclosure through a conduit to a sensor. The flow of gas through a pump is determined by measuring motor back-e.m.f. which is proportional to motor speed. In a system where motor speed is regulated by pulse width modulation of the motor drive voltage, the back-e.m.f. is sampled during intervals between the drive pulses applied to the motor, and in a further aspect the sampling is done at selected, spaced-apart or infrequent intervals such as once for every ten or once for every hundred motor drive pulses. Advantageously, in an instrument that uses a microprocessor and analog-to-digital converter to measure gas-concentration, the same microprocessor and converter can provide the PWM control of the pump, in response to the back-e.m.f. generated by the pump motor between the drive pulses.

Abstract: Systems and methods are provided through which the current to a spindle motor of the recording medium of a mass storage device is modulated to avoid anomalies in the operation of mass storage device and reduce power consumption. In the example of a disc drive, the current is modulated to prevent expected or predicted disturbances in the air bearing between a read/write head and the recording medium, and to reduce the power consumption when no disturbances are predicted or expected.

Abstract: A control system for an electric machine having a rotor position sensor that generates a rotor position signal, a velocity module that generates an electric angular velocity value based on the rotor position signal, a random pulse width modulation module that generates a switching period and a delay for a current cycle, and a phase angle compensation module that sums a sample rate, one half of the switching period, and the delay of a previous cycle and that outputs a delay time. The phase angle compensation module further multiplies the delay time and the electric angular velocity value and generates a compensating angle.

Abstract: A radiator includes a voltage regulator for providing a reference voltage, a fan including a power end connected to the reference voltage via a first resistor and a feedback end for outputting a pulse signal indicating the rotation speed of the fan, an integration circuit including an output end, and an input end connected to the feedback end of the fan for converting the pulse signal from the feedback end into a voltage signal, and a thermistor connected between the output end of the integration circuit and the reference voltage, for detecting temperature changes in order to adjust the rotation speed of the fan.

Abstract: A system of controlling an electric motor, a digital method of controlling an electric motor and an electric motor are described. The system of controlling an electric motor of N phases comprises a microcontroller (10), an A/C converter (30) associated to the microcontroller (30), a set of voltage meters (DN) associated to the A/D converter (30), a set of switches (SW2N) connected to an electric voltage (VBUS) and associated to the microcontroller (30), the microcontroller (30) selectively feeding, by means of at least two switches (SW2N) two phases (FN) of the motor (20) with the voltage (VBUS) during a period of time (TPOS), the movement of the motor inducing the electric voltages (EN), the set of meters (DN) measuring the signals of electric voltages (fN) and comparing these voltages with each other to determine the period of time (TPOS). One describes also the calculation of a parameter, called H(r), used to adjust the instants of commutation according to the constructive type of the motor.

Abstract: A brushless, synchronous direct current motor is operated by supplying a direct current voltage as an input voltage for commutating the motor phase windings. The speed of the synchronous motor is modified or varied in two speed ranges. In the first speed range, a linear change of the input voltage is carried out up to a speed threshold value. In the second speed range with higher speeds than in the first speed range, a vector modification of the input voltage is carried out, for example for controlling the speed of a fan motor.

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 powered panel control apparatus and method using an electric motor with a rotatable armature. The control generates time periods for a predetermined amount of angular rotation of the motor armature during one complete rotation. An average time period is computed over a predetermined number of time periods and compared with a threshold time period to determine if an obstacle is present in the path of movement of the panel. Transient counts are accumulated for increasing average time periods over a number of time period samples to detect an obstacle. A threshold for normal noise variations is adjusted upon detection of a rough road condition to compensate for the effect of rough road conditions on the powered panel control apparatus.

Abstract: A method and an apparatus for controlling release of a hoisting motor brake in a hoisting apparatus, where electricity is used as the driving force and a squirrel cage motor as the hoisting motor for hoisting or lowering a load attached to a hoisting member of the hoisting apparatus. Controlling of brake release comprises measuring the current and supply voltage of the hoisting motor after the start-up period of the hoisting motor and determining a variable which describes the load of the hoisting apparatus from the current and supply voltage. The variable describing the load is compared with a pre-determined limit value and hoisting or lowering of the load is interrupted if the variable describing the hoisting apparatus load exceeds the limit value set for the hoisting movement when the load is hoisted or if it exceeds the limit value set for the lowering movement when the load is lowered.

Abstract: An electric motor for operating a device for wiping a window of a motor vehicle has an electric motor part, and a control device for controlling/regulating a power of the electric motor part, the control device being formed so that it is programmable with a parameter a power limiting by limiting a torque to a nominal torque.

Abstract: A switched reluctance drive is supplied from a voltage source which varies from the voltage at which the control laws for the drive were determined. The control system compensates for this by modifying both the speed and torque values used to determine the correct firing angles for the demanded load. The system works over a very wide range of voltage variation and is independent of the shape of the torque/speed curve of the drive.

Abstract: The presence of an object in the path of an automotive vehicle window is detected. This is accomplished by sensing or observing a system variable, such as speed or motor current, and comparing this measured value to a predicted limit value of the system variable which is based upon the behavior of the system variable when there is no object present. The values are compared over predetermined time intervals and if the measured value falls out of the predicted limit value of the system variable in a direction that indicates an obstruction, then a control system detects the presence of an object and reacts accordingly by stopping or reversing the drive motor of the vehicle window.

Abstract: A method for determining the position of a movable element to be driven by a direct current motor between first and second positions includes counting ripples contained in a motor current signal as the motor rotates to drive the element. The position of the element is determined based on the counted ripples. The motor actuates, until the current signal is void of ripples, to move the element into the first position when the element is to be moved out of the first position towards the second position. The counted ripples is reset to a reset value after the motor has been actuated to move the element into the first position such that the reset value corresponds to the position of the element being in the first position. The motor actuates to move the element towards the second position after the counted ripples has been reset.

Abstract: A variable speed power tool may include a speed adjusting device and/or a maximum speed adjusting device for adjusting the operating speed, and a fixed operating speed switch. An operator adjustable speed adjusting device having a position maintaining mechanism also may be utilized. When manipulated by the operator, the fixed operating speed switch gives priority to the adjusted position of the speed adjusting device and adjusts the operating speed to a preset operating speed. In the alternative, a switching device and an internal integrated circuit may be utilized to adjust the operating speed to a target speed using feedback control. The switching device preferably selects a voltage corresponding to the target speed from either a voltage representative of the position of the speed adjusting device or a predetermined voltage representative of the present operating speed.

Abstract: A motor controller for a three-phase spindle motor used in the hard disc drive provides pulse width modulated (PWM) signals used to drive the motor. The PWM signals have duty cycles which are a function of rotational position of the motor, a magnitude control signal, a stored set of main waveform coefficients, a stored set of modifier coefficients, and a modifier signal. By varying the modifier signal, the duty cycle of the PWM signals can be varied to adjust the shape of the motor current waveform to match the torque profile of the motor.

Abstract: An adaptive motion controller for driving a servo motor. The adaptive motion controller has an amplifier including a voltage command which can be set at a voltage at which the amplifier will be operated, a frequency selector which can be set at a frequency at which the amplifier will be operated, a power supply having a current feedback, and a control for driving the servo motor in a test mode wherein the voltage command is set at a selected voltage, and the frequency selector is sequentially set with a series of different frequencies. The servo motor is operated at each frequency, and the frequency of the series of frequencies that has the lowest current feedback is determined and the frequency selector is set at that frequency when the amplifier is operated to drive the servo motor.

Abstract: A tan having a fan wheel and an electric motor driving it, and a control unit for controlling the motor output as a function of fan-specific parameters. An actual-value signal corresponding to an actual rotational speed of the fan is measured and compared with a control signal corresponding to a required speed, and the actual speed is adjusted to the required speed by means of the control unit, wherefore the actual speed and the actual motor current or supply current are measured and conducted to a microcontroller as input signal variables, whereby the fan-specific data such as wheel diameter, density of the conveying medium, fan coefficients, motor coefficients, and a preset artificial characteristic curve ps=ƒ({dot over (V)}s ) are stored in the microcontroller as default values.

Abstract: A motor controller utilizes sensors to detect the rotational speed and relative position of the motor rotor and generates a voltage vector to maintain the motor current in phase with the EMF before a voltage limit is reached. The approximate actual speed is calculated and position signals are generated by the calculator. The actual speed is compared with a command speed signal and any difference gives rise to an error signal. A proportional integrator receives the error signal and produces a correction signal for a vector rotator corresponding to the desired vertical voltage component necessary to achieve the command speed. After the voltage limit is reached, any further speed increase desired is achieved by rotation of the voltage vector with it's amplitude unchanged.

Abstract: A method for the electronic monitoring and control of the opening and closing operation of electrically operated aggregates, particularly of window lifters and sunroofs in motor vehicles, is described. A regulating unit of the aggregate is connected to a vehicle electrical system. The regulating unit is directly influenceable via electrical operating control elements, i.e., via a control-electronics interfacing circuitry connected to the aggregate. The control electronics interfacing circuitry is supplied with a signal that is a function of an accelerative force acting on a motor-vehicle body. The signal which is a function of the accelerative force, is determined from a motor speed of the regulating unit.

Abstract: Disclosed is a three phase BLDC motor driving circuit which makes a BEMF voltage generated in a motor lower than a voltage source and makes a difference between the BEMF voltage and the voltage source greater than a saturation voltage of a transistor. An emitter is coupled to the voltage source and a collector is coupled to a three phase coil so that the voltage between the emitter and collector of the transistor supplying a current to the three phase coil attenuates to a first level so as not to saturate the transistor.

Abstract: A fan speed control system for controlling the operation and speed of a fan is described. The fan speed control system includes a power control block for supplying an output voltage to the fan. An integrated circuit fan controller causes a resistor divider circuit to operably divide a selected portion of the output voltage. The integrated circuit fan controller comprises a data register which receives values indicative of control or speed operands from a host. A logic state machine translates these values into appropriate logic signals and provides the signals to the resistor divider circuit. A timing reference or an oscillator controls the proper sequencing and timing relationship of the logic state machine. To turn the fan on, the following sequence of steps occurs. The power control block is turned off causing the output voltage not to be supplied to the fan. The logic state machine controls the resistor divider circuit to divide the output voltage to be supplied to the fan.

Abstract: A method and arrangement for adaptively compensating for load changes, particularly in connection with an electric motor drive which comprises a motor, the shaft of the motor being connected to a load (3) having a known moment of inertia; a device (2), such as an inverter, to control the motor, a torque controller being arranged in connection with the device; and a speed controller (1) arranged to control the speed of the motor. The method comprises steps of determining, during the load change, an estimate (Mh) for an external torque disturbance which causes load changes, and employing the torque disturbance estimate (Mh) determined during the previous load change for compensating for the external torque disturbance in controlling the torque of the motor.

Abstract: A brushless DC motor utilizes alternating current including a plurality of phases of alternating current. Each phase of the plurality of phases is supplied to a respective phase winding group. Each phase winding group is wound on a stator, and each phase of the plurality of phases of alternating current is split into a plurality of subphases of alternating current subsections. Each phase winding group includes a plurality of phase winding subsections and each phase winding subsection of the plurality of phase winding subsections is supplied by a subphase of a plurality of the plurality subphases of alternating current. A means for switching current so as to conduct the alternating current through at least one of the plurality of phase winding subsections is also included.

Abstract: In a closed loop control system that governs the movement of an actuator a filter is provided that attenuates the oscillations generated by the actuator when the actuator is at a resonant frequency. The filter is preferably coded into the control system and includes the following steps. Sensing the position of the actuator with an LVDT and sensing the motor position where motor drives the actuator through a gear train. When the actuator is at a resonant frequency, a lag is applied to the LVDT signal and then combined with the motor position signal to form a combined signal in which the oscillation generated by the actuator are attenuated. The control system then controls ion this combined signal. This arrangement prevents the amplified resonance present on the LVDT signal, from causing control instability, while retaining the steady state accuracy associated with the LVDT signal.

Abstract: A speed control method for an SR motor using a load with a large mechanical inertia that performs a PWM in an acceleration state wherein a speed of the motor radically changes and switches an inverter transistor for a previously determined time in a steady state wherein the speed thereof becomes an uniform level, thereby regularly fixing a time for which a current flows to motor coils connected with the switching transistor.

Abstract: An apparatus for controlling an actuator in response to a target speed voltage signal, the actuator having a moveable member and having a coil that influences movement of the member. A first summing node is provided having a control output voltage, for summing or subtracting voltages applied thereto, as the case may be and receiving the target speed voltage signal at a first, summing input thereto. A proportional compensation unit is provided, receiving the control output voltage and providing as an output a proportionally compensated output signal. An integral compensation unit is provided, receiving the control output voltage and providing as an output an integrally compensated output signal. An inverse compensation unit is provided, receiving the target speed voltage signal as an input and providing an inversely compensated output signal having a voltage corresponding to the voltage of the target speed voltage signal multiplied by the inverse of a predetermined amplification factor.

Abstract: In a motor, drive transistors (7, 9) are turned off by drive signals I, J output from a control circuit (10) at a point adjacent to a phase changeover point of the energizing to drive coils (1, 2), so that no drive current flows through the drive coils (1, 2). Since the counter electromotive forces of the drive coils (1, 2) become small, the drive current can be eliminated before the drive current sharply rises. As a result, sharp dropping of the drive current can be prevented. This allows variation in rotational torque of a motor to be suppressed, and thus reduces vibrational noise in the motor.

Abstract: A digital control device used with a direct-current (DC) motor is disclosed. The digital control device controls the revolving speed of a DC motor by outputting a certain intensity of current according to the digital states of a group of digital signals inputted therein from the external such as a computer system. The digital control device performs a precise control for the revolving speed of the DC motor at low cost, and the speed levels of the DC motor can be varied with the circuitry details of the digital control device.

Abstract: A speed monitoring and control method for a brushless motor controlled by a controller which provides switching control signals to a plurality of switching elements includes comparing one line voltage of the motor with a signal representing a voltage at the neutral node of the motor, to generate a comparison signal. The method also includes ANDing the comparison signal with a switching control signal to generate a composite feedback signal representative of a rotational speed of the motor's rotor relative to a speed of a rotating magnetic field generated by the stator.

Abstract: A method of controlling motor speed. The motor speed control apparatus includes an encoder in mechanical association with the motor. The encoder has one channel providing an encoder signal having a rising and falling state transition for each period of the encoder signal. The periodic frequency of the state transitions are used to precisely measure instantaneous motor speed. A comparitor then compares the periodic frequency with a predetermined motor speed to provide an error signal, representative of the difference. A feedback control system affects the motor speed dependent on the error signals. In a further embodiment, the encoder includes two channels and four state transitions.

Abstract: A control circuit and method for controlling a switched reluctance motor are provided. The control circuit includes a tone wheel and a Hall effect sensor for generating a position feedback signal indicative of the position of the motor. The control circuit also includes a sensing resistor for generating a current feedback signal indicative of a level of current in a phase coil of the motor. Finally, the control circuit includes first and second switches connected to opposite ends of the phase coil for controlling the level of current in the phase coil responsive to the position feedback signal and the current feedback signal.

Abstract: A controller for energizing a power-operable element, such as a sunroof, window, door, vehicle seat, a component of a major appliance or of a machine or of a conveyor system. The disclosed controller senses both hard and soft obstructions and de-activates or otherwise alters operation of a motor that drives the element when an obstruction is detected. The controller can also be used to actuate a brake. The controller senses obstructions during start-up of the motor and regulates the speed of the power-operable element by pulse width modulating motor energization signals.

Abstract: To provide an electric motor control system capable of reducing torque pulsation resulting from an intermittent control and assuring a smooth acceleration/deceleration. In a speed reference signal converter 9, a deviation between a last time value .omega..sub.r-1 and a this time value .omega..sub.r of the speed reference signal .omega..sub.r of a master control system 1 is computed, the speed reference signal .omega..sub.r from the master control system is converted into a speed reference signal .omega..sub.r * conforming to the computing cycle of the motor control system according to a ratio between the updating cycle of the speed reference signal from the master control system and a computing cycle in a motor control system and said deviation, a motor driving signal is produced according to this converted speed reference signal .omega..sub.r * and a motor 6 is driven.