Abstract: A circuit for controlling rotation speed of a computer fan includes a fan connector providing for controlling the rotation speed of the computer fan, a rotation speed detector providing for detecting the rotation speed of the computer fan, a BIOS chip connected to the fan connector via the rotation speed detector and provided for receiving, and comparing rotation speed signals from the rotation speed detector, a super I/O chip connected to the BIOS chip and provided for outputting either a PWM signal or another PWM signal to be converted to a voltage signal to control rotation speed of the computer fan according to the result of the comparison, a integrated circuit connected to the super I/O chip and the fan connector and configured for converting the another PWM signal to an analog voltage signal.

Abstract: A device and a method are provided for determining the after-run voltage of a direct current motor which is operated via cycled control. In normal operation the direct current motor is controlled via PWM control and a first specifiable pulse/no-pulse ratio. An evaluation unit is provided for determining an after-run voltage variable which is representative of the after-run voltage of the motor. Furthermore, for determining the after-run voltage variable the direct current motor is controlled via a specifiable, variable second pulse/no-pulse ratio.

Abstract: A motor controller for a direct current motor includes a first node receiving first PWM signals having a duty cycle indicative of a desired rotational speed of said motor and an input node receiving second digital signals, the frequency of said second signals indicative of the rotational speed of said motor. A frequency-to-PWM circuit is coupled to the input node to provide second PWM signals having a duty cycle corresponding to the rotational speed of the motor. A duty cycle comparator has a first input coupled to the first node and a second input coupled to the second node to generate a control signal for controlling the rotational speed of the motor.

Abstract: A circuit for controlling rotation speed of a computer fan includes a fan header for connecting to a 4-pin fan or a 3-pin fan, a jumper device, an amplifier, and a controller. The jumper device has a first pin for receiving a controlling signal, and connected to a first power source, a second pin connected to the fan header, and a third pin connected to the first power source. The amplifier has an input terminal connected to the third pin of the jumper device via an integrator. The controller has a first terminal connected to an output terminal of the amplifier, a second terminal connected to a second power source, and a third terminal connected to the fan header and connected to a positive input terminal of the amplifier via a resistor. The first pin of the jumper device is selectively connected to the second or third pin.

Abstract: A fan speed control circuit is used for controlling rotation speed of a fan. The fan speed control circuit receives a pulse width modulation (PWM) signal from a system and comprises a programmable control unit and a current control unit. The programmable control unit receives the PWM signal, is connected to a Hall element for receiving a voltage signal therefrom, and provides a control signal. The current control unit takes the control signal to control current flowing through a stator coil unit of the fan so as to control the speed of the fan. The programmable control unit has a program written for the PWM signal, and when the fan speed control circuit is used in another system with a different PWM signal, the programmable control unit can be given a new program for the different PWM signal for controlling the speed of the fan.

Abstract: A torque compensation method and system for a DC brushless motor. When the DC brushless motor coupled with an asymmetric load is rotating, the difference between an instant current and an average current of a shunt resister is an index of adjusting control signals within an absolute rotor position for the purpose of approaching the corresponding instant current to the average current.

Abstract: A motor controller is provided with a velocity processing unit that determines a corrected target rotation velocity by correcting the inputted target rotation velocity of the motor in accordance with a velocity deviation between the inputted target rotation velocity and an actual rotation velocity detected from the motor, a first PWM circuit that repeatedly outputs an on-signal having a first pulse width at a first carrier frequency, wherein the first pulse width of the on-signal is modulated by the first PWM circuit in accordance with the corrected target rotation velocity, a second PWM circuit that repeatedly outputs an on-signal having a second pulse width at a second carrier frequency, wherein the second pulse width is different from the first pulse width, the second carrier frequency is lower than the first carrier frequency, and the second pulse width of the on-signal is modulated by the second PWM circuit in accordance with the corrected target rotation velocity, an AND circuit that receives the on-sig

Abstract: Systems and methods for determining the occurrences of pulses for implementing a pulse count monitoring method for driving a brushed DC motor driven by a pulse width modulated (PWM) driving current. The method comprises acquiring the driving current signal; performing peak detection on the acquired signal; identifying the largest peaks and thus determining the occurrence of pulses. The peak detect is implemented by fast peak detection or diode peak detection operable to detect appropriate peak widths as determined by the chosen PWM frequency, duty cycle and PWM pulse height.

Abstract: A method of dynamic motor braking is disclosed herein. The method comprises: dissipating reverse energy in a motor within motor windings during a non-current supplying period of a commutation sequence by intermittently shorting the motor windings. The motor windings are shorted by simultaneously turning on all switches that are connected to a voltage source or to ground in a three-phase bridge motor control.

Abstract: The invention to an electronic control system, controlled by a pulse width-modulated signal (SG) related to earth, for regulating the voltage (Umot) across a high-side load (M), in particular a fan control unit for motor vehicles. The circuit part that converts the pulse width-modulated signal (SG) into the reference input variable (U?) needed for the regulation uses the positive potential of the supply voltage (V2) as reference potential, so that the reference input variable (U?) is likewise related to the positive potential of the supply voltage and the control signal (SG) is converted by means of a Zener diode (D1) and by means of a resistor (R5) connected parallel to the Zener diode (D1) into a control signal related to the positive supply potential and is further converted with a low pass filter (R7, C1) into a linear control signal, which serves as input reference variable (U?).

Abstract: A fan control system includes a power source, a switch control circuit, a switch control signal delivering unit and a fan circuit module. The power source outputs a nominal power, the switch control circuit electrically connects to the power source, the switch control signal delivering unit electrically connects to the switch control circuit and can send a power control signal to the switch control circuit, and the fan circuit module electrically connects to the switch control circuits. In an initial operation state, the nominal power output from the power source can be reduced to a control power sending to the fan circuit module via the switch control circuit to drive at least one fan within the fan circuit module, and then the power control signal controls the control power after the switch control signal delivering unit sends the power control signal to the switch control circuit.

Abstract: Calibration of a motorized roller shade is accomplished by calculating a radius of a roller tube and thickness of a shade fabric rotatably supported by the roller tube. First, a lower edge of the shade fabric is moved to a first position at a first linear distance from a predetermined position. Second, a first number of revolutions of the roller tube between the first position and the predetermined position is determined. Next, the lower edge of the shade fabric is moved to a second position at a second linear distance from the predetermined position and a second number of revolutions between the second position and the predetermined position is determined. Finally, the tube radius and the fabric thickness are calculated from the first and second linear distances and the first and second numbers of revolutions. The tube radius and the fabric thickness are used to control the linear speed of the lower edge of the shade fabric.

Abstract: In one aspect, a control circuit to control a speed of a motor includes a PWM oscillator configured to generate a PWM output signal having a duty cycle. The speed of the motor is controlled by the PWM output signal to be proportional to the duty cycle. The control circuit also includes a duty cycle control circuit responsive to a duty cycle selection signal and coupled to the PWM oscillator. The duty cycle control circuit is configured to compare a voltage reference and a supply voltage. The duty cycle control circuit controls the duty cycle of the PWM output signal to be inversely proportional to the supply voltage.

Abstract: The present invention discloses a control system for controlling a motor for a heating, ventilation and air conditioning (HVAC) or a pump comprising: an opto-isolated speed command signal processing interface into which a signal for controlling a speed of the motor is inputted and which outputs an output signal for controlling the speed of the motor being transformed as having a specific single frequency; a communication device into which a plurality of operation control commands of the motor; an opto-isolated interface for isolating the plurality of operation control commands inputted through the communication device and the transformed output signal for controlling the speed of the motor, respectively; a microprocessor, being connected to the opto-isolated interface, for outputting an output signal for controlling an operation of the motor depending on the plurality of operation control commands and the transformed output signal for controlling the speed of the motor; a sensor, being connected to the motor,

Abstract: An electric fan device includes a motor which drives an electric fan for a vehicle, a control switch which controls a motor current supplied to the motor, and a control unit which controls an on/off operation of the control switch with pulse-width modulation. The control unit outputs a PWM pulse having a main PWM pulse and a vibration reducing pulse within one cycle to the control switch.

Abstract: A device and a method are provided for determining the after-run voltage of a direct current motor which is operated via cycled control. In normal operation the direct current motor is controlled via PWM control and a first specifiable pulse/no-pulse ratio. An evaluation unit is provided for determining an after-run voltage variable which is representative of the after-run voltage of the motor. Furthermore, for determining the after-run voltage variable the direct current motor is controlled via a specifiable, variable second pulse/no-pulse ratio.

Abstract: An apparatus for detecting a type of fan and controlling the fan, the fan providing during operation a tachometer signal indicating a speed of the fan, the apparatus includes: a direct current (DC) generator for coupling to the fan and configured to provide a first voltage to the fan; a resistor for providing, while the DC generator provides the first voltage, a sensed voltage relating to the type of the fan, wherein the resistor is connected to a reference voltage and for coupling to a pulse-width modulation (PWM) control terminal of the fan; an input judgment component coupled to the resistor to receive the sensed voltage, the input judgment component being configured to determine whether the fan is a 4-wire PWM fan with an internal pull-up resistor based on the sensed voltage and to provide a judgment signal indicating the determination; a PWM generator coupled to the input judgment component to receive the judgment signal, the PWM generator being configured to provide to the fan a PWM control signal to co

Abstract: A circuit for controlling rotation speed of a computer fan includes a fan connector providing for controlling the rotation speed of the computer fan, a rotation speed detector providing for detecting the rotation speed of the computer fan, a BIOS chip connected to the fan connector via the rotation speed detector and provided for receiving, and comparing rotation speed signals from the rotation speed detector, a super I/O chip connected to the BIOS chip and provided for outputting either a PWM signal or another PWM signal to be converted to a voltage signal to control rotation speed of the computer fan according to the result of the comparison, a integrated circuit connected to the super I/O chip and the fan connector and configured for converting the another PWM signal to an analog voltage signal.

Abstract: Disclosed is a drive circuit for generating the drive current used to energize the windings of a motor. The drive circuit includes a data processing unit that produces two outputs used to control an H-bridge and generation of the drive current. One output, a commutation signal, controls the timing of generation of drive current. The drive current in turn is determined based on the other output, a speed signal. The speed signal waveform includes blanking portions to avoid occurrences of shoot through in the H-bridge.

Abstract: A fan motor control device comprises a clock signal generator and a drive unit. The clock signal generator generates a low-frequency clock signal. A frequency of low-frequency clock signal is less than 23 KHz. The drive unit converts the low-frequency clock signal to a high-frequency drive signal and outputs the high-frequency drive signal to drive the fan motor. A frequency of the high-frequency drive signal is higher than 23 KHz.

Abstract: A method for controlling a heat-dissipating fan for an electronic component includes the steps of: detecting a temperature of the electronic component, and outputting a first control signal corresponding to the temperature thus detected; receiving a load current of the electronic component, and converting the load current into a second control signal; and controlling a rotating speed of the heat-dissipating fan with reference to the first control signal and the second control signal. A device employing the method includes a current detecting module adapted for detecting a load current, a temperature control circuit adapted for detecting a temperature, and a logic circuit unit coupled to the current detecting module and the temperature control circuit and controlling a rotating speed of a heat-dissipating fan.

Abstract: A fan speed control device includes a management selection module, a first and a second buffers, a resistor, a transistor, and a switch. Depending upon whether a motherboard supports a system of a baseboard management control or not, the fan speed control device selectively uses an indicative signal of a serial input and output interface or an indicative signal of the baseboard management control to indicate a power-on status. At the power-on moment, the fan speed control device controls the fan to operate at its minimum speed, so that a system crash due to a power output shortage of a power supply can be avoided. As the system enters stable operation, the fan speed is controlled by a pulse width modulation signal.

Abstract: A protect-control device capable of limiting current for reducing noise resulting from switchover of a motor includes a motor coil set, a driving unit, a sensing unit and a control unit. The motor coil set constitutes a motor. The driving unit is electrically connected to the motor coil and provides a driving level to pass through the motor coil for driving the motor. The sensing unit is electrically connected to the motor coil set, provides a preset reference level, detects the driving level, compares the driving level to the preset reference level and outputs identifying signal. The control signal is electrically connected to the driving unit, the sensing unit and a Hall component, adjusts the driving level based on the identifying signal for driving unit output maintaining a basic duty cycle.

Abstract: A motor drive control circuit includes a rotation control amplifier that compares the lower of a voltage limiting reference voltage of a reference voltage source and a rotation speed control voltage, which controls the rotation speed of the motor, on a terminal with a peak voltage from an impedance element that detects a drive current of a motor. The motor drive control circuit further includes a rotation limiting comparator that compares a voltage that is substantially equal to the voltage limiting reference voltage with the peak voltage, a synthesis circuit that amplifies rotation position detection signals from the motor according to the output voltage of the rotation control amplifier, a PWM output comparator that compares the outputs of the synthesis circuit with a triangular wave voltage and outputs PWM signals, and a motor-driver control circuit that removes an output period of the rotation limiting comparator from the ON period of each PWM signal and controls a motor driver that drives the motor.

Abstract: A food waste disposer has a motor driven with pulse width modulation (“PWM”). A grinding profile is controlled based on PWM values of the PWM controller driving the motor. In an aspect, controlling the grinding profile includes varying the speed of the motor based on the PWM values. In an aspect, the grinding profile is initiated after the food waste disposer is started and a PWM value exceeds a set value indicating the presence of a grinding load in a grinding section of the food waste disposer. In an aspect, it is determined that the grinding load has been sufficiently ground once the PWM value does not exceed a first set value after the grinding profile has been initiated. In an aspect, corrective action is initiated when the PWM value exceeds the set value after a predetermined period of time.

Abstract: A driving apparatus for a DC brushless motor of a ceiling fan is provided. By setting at least one coder and one sensor outside the DC brushless motor, the driving apparatus can sense the position of magnetic poles of the motor for driving the motor. Meanwhile, a controller set with the motor stores the rotation speed of the motor before being turned off by detecting the turn-off time of a turn-on/off signal.

Abstract: An apparatus is used for controlling a rotating direction of a fan. The apparatus comprises a power source, a signaling unit, a switching unit, and an activating module. The power source is used for supplying power for the apparatus. The signaling unit is used for generating direction-control signals. The switching unit is connected to the power source and the signaling unit, and used for controlling the switching unit to work. The activating module is connected to the switching unit and the fan, and used for driving the fan to selectively rotate in one of two opposite directions based on the direction-control signals. A method for driving the fan in the two directions is also disclosed.

Abstract: The invention provides, as an aspect thereof, an document reading apparatus that includes: a speed calculating unit that calculates a speed related to the rotation of a motor on the basis of a signal that is outputted from an encoder; and a controlling unit that calculates control amount on the basis of the speed calculated by the speed calculating unit so as to control the rotation of the motor in accordance with the calculated control amount. In the configuration of an document reading apparatus according to this aspect of the invention, the above-mentioned controlling unit controls the motor with an increase in the control amount in a case where there occurs no change in the signal that is outputted from the encoder for a certain period of time. The increase in the control amount is based on the length of time that has elapsed since the last change in the signal.

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 control circuit for fan operating comprises a drive operating circuit, a potential modulating circuit, a comparator and a switch circuit. The drive operating circuit at least has a voltage source, a drive IC, a Hall IC and a motor coil winding, the drive IC is connected with the voltage source, and the Hall IC and the motor coil winding are connected with the drive IC. The potential modulating circuit is connected with the drive IC of the drive operating circuit and has a modulating signal source to provide a PWM signal with a duty cycle. The comparator has an input end and an output end, the input end is connected with the potential modulating circuit, and potential state of the output end is determined in accordance with the duty cycle of the PWM signal. The switch circuit is connected with the drive IC of the drive operating circuit and the output end of the comparator, and operating state of the drive IC of the drive operating circuit is determined in accordance with potential state of the output end.

Abstract: An exemplary method for controlling rotation speed of a computer fan includes: judging the type of a fan by comparing two rotation speeds detected before and after changing a duty cycle of a PWM signal respectively; controlling the computer fan as a 4-pin fan the PWM signals if the rotation speeds are different; and controlling the computer fan as a 3-pin fan via voltage signals converted from the PWM signals if the rotation speeds are equal. And an exemplary circuit for controlling rotation speed of a computer fan is capable of controlling rotation speed of the 4-pin fan via PWM signals, and controlling rotation peed of the 3-pin fan via voltage signals converted from PWM signals.

Abstract: A motor controlling device and a motor controlling method are provided. The motor controlling device includes a first sensor, a second sensor and a signal switching circuit. The signal switching circuit is electrically connected to the first and second sensors, respectively. The signal switching circuit is switched to the first sensor to output a first switching phase signal to drive a motor when the motor starts to operate. The signal switching circuit is switched to the second sensor to output a second switching phase signal to drive the motor when a predetermined switching condition is satisfied with a predetermined value during the motor operation.

Abstract: A motor speed control circuit includes: a voltage generating circuit configured to output a reference voltage corresponding to a target rotation speed of a motor and a speed voltage corresponding to a rotation speed of the motor, and change either the reference voltage or the speed voltage according to a temperature; a comparison circuit configured to compare the speed voltage with the reference voltage; and a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit.

Abstract: A driving device is provided for controlling rotation of a motor. The driving device comprises an inputting module, a comparing module and a processing module. The inputting module includes a first current source, a first voltage source and a first capacitance. The first capacitance is coupled between the first current source and the first voltage source for charging/discharging and generating a voltage signal. The comparing module is coupled to the inputting module for comparing a selecting signal with the voltage signal and generating a comparing signal. The processing module is coupled to the comparing module and generates a control signal according to a clock signal and the comparing signal, wherein the driving device controls the rotation of the motor by the control signal.

Abstract: A power-saving, high-performance, low-noise brushless motor control circuit assembly is disclosed formed of a power supply circuit, a booster and compensation circuit, a voltage regulator circuit, a microprocessor, a back electromagnetic force sensor, three driver circuits, and three output circuits. By means of detecting back electromagnetic force, the magnetic pole position of the brushless motor is known accurately, ensuring accurate operation control. By means of providing a high voltage to drive the drive circuits, the field effect transistors of the output circuits are operated under full conduction, saving much power consumption and lowering the working temperature of the brushless motor.

Abstract: A method and circuit for determining the speed and/or counting the revolutions of brush and commutator motors is described. The method and circuitry detects signals present on the windings of the motor due to commutation that occurs at the brushes and commutator of the motor. This method can be used to simply monitor & indicate the motor speed and revolutions or to form the basis of a motor control.

Abstract: A high torque AC motor of the repulsion type that includes at least four stator poles and an armature with chordally oriented windings. The armature windings are cyclically shorted and opened in groups at appropriate angular positions of the armature by a non-contact switch circuit carried on the armature.

Abstract: A motor control method and a motor control device are provided. The control method includes the steps of receiving a current feedback signal from a coil switching circuit, while the motor is rotating, for generating a separate signal, and comparing the current feedback signal and the separate signal for generating a motor control signal so as to control the operation of the motor.

Abstract: A motor controlling method and apparatus thereof are provided. The control method includes the steps of receiving a switching phase signal of coil while the motor is rotating, for generating a separate signal, comparing the phase signal and the separate signal to generate a first control signal, generating a current feedback signal equivalent to the first control signal, and comparing the current feedback signal and the separate signal for generating a second control signal so as to control the operation of the motor.

Abstract: A method and apparatus is provided for processing signals from a Hall effect device arrangement coupled to a monolithic brushless DC motor where the motor is driven by a PWM circuit providing PWM drive signals.

Abstract: A method of operating a direct current motor fan assembly is provided in which a motor controller operates to apply full power to kick-start a motor to overcome static forces. As soon as a sensor determines that the motor has begun to rotate, the motor controller changes the motor drive level from full power to a predetermined lower level to maintain a desired rotational speed.

Abstract: The present invention discloses a high-current high-resolution driving circuit comprising a controller, a digital-to-analog converter and a voltage-to-current converter. The controller is provided for receiving a control signal for operating a load and outputting a digital signal corresponding to the control signal. The digital-to-analog converter is provided for generating an analog voltage signal corresponding to the digital signal. The voltage-to-current converter is provided for generating a current signal corresponding to the analog voltage signal and transmitting the current signal to the load in order to drive the load.

Abstract: A circuit and a method for controlling the rotating speed of a brushless direct current (BLDC) motor are provided, whose goal is solving the stall problem encountered by conventional BLDC motors driven by pulse width modulation (PWM). The circuit includes a closed-loop control mechanism for adjusting the duty cycle of the motor current of the BLDC motor, thus controlling the rotating speed of the motor. The closed-loop control is based on the comparison of a signal proportional to the actual rotating speed and another signal proportional to the predetermined target rotating speed.

Abstract: An improved fan arrangement features a radial or diagonal fan (370) with which a direct current motor (32) is associated as its drive motor, further comprising a digital control element (23, 24) which executes a program, for controlling the current flowing through the direct current motor (32), which program is so configured that it applies a substantially constant current in the motor (32) in the working rotation speed range of the fan.

Abstract: A method of controlling a motorized window treatment provides for continued operation of the motorized window treatment during an overload or low-line condition. The motorized window treatment is driven by an electronic drive unit having a motor, a motor drive circuit, and a controller. The controller controls the motor drive circuit to drive the motor with a pulse-width modulated signal generated from a bus voltage. The controller is operable to monitor the magnitude of the bus voltage. If the bus voltage drops below a first voltage threshold, the controller stops the motor or reduces the duty cycle of the pulse-width modulated signal to allow the bus voltage to increase to an acceptable magnitude. When the bus voltage rises above a second voltage threshold, the controller begins driving the motor normally once again. During an overload or low-line condition, the controller is prevented from resetting, while driving the motor with minimal interruption to the movement of the motorized window treatment.

Abstract: An apparatus for controlling rotational speed of a fan includes a sensor module, a single chip microcomputer (SCM) module, and a driving module. The sensor module collects rotational speed signals of a fan, and converts the rotational speed signals to voltage signals. The SCM module receives the voltage signals from the sensor module and compares the voltage signals with a predetermined rotational speed value stored in the SCM module, and outputs a control signal according to the comparison. The driving module receives the control signal from the SCM module, and outputs a pulse width modulation (PWM) signal to control the rotational speed of the fan.

Abstract: A protect-control device capable of limiting current for reducing noise resulting from switchover of a motor includes a motor coil set, a driving unit, a sensing unit and a control unit. The motor coil set constituting a motor. The driving unit is electrically connected to the motor coil and provides a driving level to pass through the motor coil for driving the motor. The sensing unit is electrically connected to the motor coil set, provides a preset reference level, detects the driving level, compares the driving level to the preset reference level and outputs identifying signal. The control signal is electrically connected to the driving unit, the sensing unit and a Hall component, adjusts the driving level based on the identifying signal for driving unit output maintaining a basic duty cycle.

Abstract: A motor driving circuit drives a motor on receipt of an error signal having a digital value corresponding to a deviation between a current rotation speed of the motor, which is the subject to be driven, and its target value. A digital filter eliminates a high-frequency component of the error signal. A driving unit controls an electric current flowing through the motor in accordance with the digital value of the error signal from which the high-frequency component is eliminated by the digital filter. An upper-limit value setting unit sets an upper limit value to the digital value of the error signal input to the digital filter. The upper-limit value setting unit is configured to be capable of changing the upper limit value in accordance with a setting signal from the outside.

Abstract: A control circuit for a direct current motor is described. In accordance with the principles of the invention, a duty cycle comparator is provided to control the speed of the motor.

Abstract: A fuel supply system comprises an engine control unit (ECU), a fuel pump with a built-in pump motor which is PWM controlled based on a control signal from the ECU, a pump controller for controlling supply of electric power to the pump motor, and sensors for detecting an operating state of the engine. A control section of the pump controller controls to change a frequency to be lower as a duty ratio of a PWM control signal to operate a power transistor of an output circuit is higher and inversely to change the frequency to be higher as the duty ratio is lower.