Abstract: The present invention relates to a circuit for detecting a functional status of an electro-motor. Typical electro-motors need additional components to identify the functional status of the motor. This means additional weight for such motors determining the functional status. According to the present invention, a circuit is provided using a part of a motor as a sensor for detecting the functional status of the electro-motor.

Abstract: A cooling system constructed to cool down an accumulator mounted on a motor vehicle is herein presented. The cooling system sequentially controls an air blower to restrict the air blow to the accumulator, controls the air blow mode switchover module to switch over the active air blow mode after restriction of the air blow to the accumulator, and controls the air blower to release the restriction of the air blow to the accumulator after the switchover of the active air blow mode by the air blow mode switchover module.

Abstract: Systems and methods of controlling a fan in an electronic system are disclosed. One example method includes obtaining a control setting of the fan and current speed of the fan. The example method further includes determining a fan speed threshold associated with the obtained control setting. The example method further includes comparing the fan speed threshold to the current speed. The example method further includes generating an alert based on the comparison.

Abstract: A fan speed control circuit includes a first fan, a second fan, a first temperature sensor, a second temperature sensor, a PWM regulator, and a driving module. The first temperature sensor senses a temperature of the first component to generate a first temperature signal. The second temperature sensor senses a temperature of a second component to generate a second temperature signal. The PWM regulator is connected to the first temperature sensor and the second temperature sensor. The PWM regulator generates a first PWM signal according to the first temperature signal and generates a second PWM signal according to the second temperature signal. The driving module is connected to the PWM regulator. The driving module generates a first driving voltage provided to the first fan according to the first PWM signal. The driving module also generates a second driving voltage provided to the second fan according to the second PWM signal.

Abstract: An alternating current-to-direct current (AC-to-DC) power supply has a first stage providing a first DC voltage and a second stage providing a second DC voltage. The AC-to-DC power supply has a first efficiency at the first stage and a second efficiency at the second stage that is less than the first efficiency. The second DC voltage is also less than the first DC voltage. A blower is electrically connected to the first stage of the AC-to-DC power supply to receive the first DC voltage from the AC-to-DC power supply to power the blower. Electrical connection of the blower to the first stage of the AC-to-DC power supply instead of to the second stage of the AC-to-DC power supply wastes less power and is more efficient.

Abstract: The model train control system includes a remote control device that receives user input with respect to various train functions such as desired speed and effects, and that generates commands based on that input in order to cause the model train to perform in a desired manner. In an embodiment of the invention, the model train controller comprises control input devices that permit user control over corresponding control features of the model train. A touch screen display may be coupled to the housing and adapted to receive user selections regarding the control feature. A processor is operatively coupled to the control input devices and the touch screen display. The processor is adapted to generate at least one model train command to be transmitted to the model train based at least in part on a user input received from either one of the control input devices or the touch screen display.

Abstract: An automated movable barrier control system component (11) as comprises a part of a movable barrier control system (10) has an audible speech output device (21) operably coupled thereto. These elements can share a common housing (22). The audible speech output device (21) can audiblize one or more items of stored speech content relating to one or more aspects of the component itself, other components within the system, and/or the system itself.

Abstract: A method for ascertaining measured values in a cyclically controlled system, the cyclic control having control time periods in which the system is controlled, and no-control time periods in which the system is not controlled, having the following operations of determining first integration time periods as a function of the cyclic control, the first integration time periods being situated within at least one of the control time periods, and/or determining second integration time periods as a function of the cyclic control, the second integration time period being situated within at least one of the no-control time periods; detecting one of the measured variables of the system dependent on the control; ascertaining summation and/or integration values by summation and/or integration of the measured variable during the first and/or second integration time periods; ascertaining the measured value for at least one of the control time periods and/or no-control time periods on the basis of time data of the first and/

Abstract: A fan rotary speed controlling device includes a base voltage generating circuit, a first voltage generating circuit, a second voltage generating circuit and a compensation controlling circuit. The base voltage generating circuit receives a pulse width modulation signal and outputs a base voltage signal. The first voltage generating circuit receives the pulse width modulation signal and generates a first voltage signal according to the pulse width modulation signal. The second voltage generating circuit receives a fan rotary speed signal and generates a second voltage signal according to the fan rotary speed signal. The compensation controlling circuit outputs a voltage deviation compensation signal according to the first voltage signal and the second voltage signal. Hence, the fan rotary speed controlling device provides a stable rotary speed.

Abstract: A self-adapting soft-starter device includes an electric current limiter limiting electric current supplied to the motor to a preset maximum current limit, a ramp-up time determiner determining the actual ramp-up time of the electric motor, a storing device storing a preset minimum ramp-up time, a comparator comparing the determined actual ramp-up time with the preset reference ramp-up time, a replacing device replacing the preset maximum current limit with an auto-adapted current limit based upon the outcome of the comparison between the determined actual ramp-up time and the preset reference ramp-up time. The soft-starter automatically optimizes the maximum current limit driven by the motor to match its load requirements which is useful to cater for load variations with time during the lifetime of the product in the application by avoiding the need for human intervention to change the soft-starter settings. Wear and tear is also reduced, extending motor lifetime.

Abstract: Disclosed is a multi-speed control apparatus for a fan motor. The apparatus includes a driving member, a motor speed sensing member, a resistor circuit, a voltage-division resistor, and a multi-segment switch. The driving member has a controlled end connected with the multi-segment switch. The driving member has an output end connected with the fan motor. The driving member has a detection end connected with the motor speed sensing member. The resistor circuit includes some resistors with various resistances. The multi-segment switch interconnects the resistor circuit, the voltage-division resistor, the controlled end of the driving member, and a voltage source. This switch is optionally connected to the resistor disposed in the voltage source or voltage-division resistor. An input voltage is created across the resistor by dividing the voltage. The driving member is therefore provided for driving the fan motor to a rotating speed according to the input voltage.

Abstract: The present invention relates to a door drive, in particular a garage door drive, with a door control and with a programming unit for programming the door control during operation and/or maintenance of the door drive. In accordance with the invention, the programming unit is configured as an external device, wherein for operation and/or maintenance of the door drive a data transmission connection can be established between the programming unit and the door control.

Abstract: A speed adjustment circuit for a plurality of fans includes a voltage input terminal, a plurality of speed control modules, and a fan tachometer. Each of the speed control modules includes a fan connector, a speed adjusting unit, and a detector switch unit. The speed adjusting unit includes a switching control unit, a voltage adjusting chip, and a variable resistor. The detector switch unit includes a first switch. The voltage input terminal connects to the input terminal of the voltage adjusting chip through the switching control unit. The output terminal of the voltage adjusting chip connects to the power pin of the fan connector. The adjusting terminal of the voltage adjusting chip connects to ground through the variable resistor, and connects to the output terminal of the voltage adjusting chip through a resistor. The detection pin of the fan connector connects to the fan tachometer through the first switch.

Abstract: A method for controlling a motor can suppress an influence of speed variation due to cogging of the motor. The method includes performing a preliminary drive process to output a first driving signal to the motor to move the mechanism, performing the preliminary drive process to output a second driving signal corresponding to a cogging period of the motor to the motor as well as output the first driving signal, to move the mechanism, determining parameters which include an output waveform and output timing of the second driving signal based on a speed of the mechanism in the preliminary drive process, and outputting the second driving signal according to the determined parameters to the motor as well as outputting the first driving signal to the motor in an actual drive process to perform predetermined processing by moving the mechanism.

Abstract: A rotation control circuit comprises a motor-driving unit and a rotation-switching unit. The motor-driving unit is coupled to a motor of a fan. The rotation-switching unit is coupled to the motor-driving unit and has at least a charging-discharging circuit for generating a rotation control command, the rotation control command controls the motor to rotate in a forward direction for a time period when the motor starts to operate, and controls the motor to rotate in a backward direction opposite to the forward direction.

Abstract: A motor control apparatus and a motor control method determine whether the motor is in a back-pressure area so as to provide different rotation-speed control signals. When the fan is in the low duty cycle, a first circuit loop is switched on, so that the fan has more accurate rotation speed. When the fan is in the high duty cycle, a second circuit loop is switched on, so that the rotation speed of fan does not be limited to a constant rotation-speed as the fan enters the back-pressure area. Thus, the fan has larger airflow quantity and higher airflow pressure.

Abstract: A current detecting device includes a current leveling unit, a first wire and a current detecting unit. The current leveling unit is configured to level a drive current that is passed through a motor drive unit to drive a motor. The first wire is configured and arranged to carry flow of a motor current that has been passed through the motor and the drive current that has been leveled by the current leveling unit. The current detecting unit is configured to detect a sum of the motor current flowing on the first wire and the drive current that has been leveled flowing on the first wire.

Abstract: An electric power tool is provided that includes a motor as a driving source, a first operation switch, a first semiconductor switch, and a second semiconductor switch. The first operation switch is operated by a user to be turned ON/OFF. The first semiconductor switch, provided on a current path from the power source to the motor, includes at least one semiconductor switching device. When the first operation switch is OFF, the first semiconductor switch is turned OFF to interrupt the current path. When the first operation switch is ON, the first semiconductor switch is turned ON to close the current path. The second semiconductor switch is provided on the current path in series with the first semiconductor switch and includes at least one semiconductor switching device. The second semiconductor switch closes/interrupts the current path by being turned ON/OFF in accordance with an input control signal.

Abstract: A first and a second drive current for an electrical drive are generated as a function of a nominal value for a movement variable, such as drive torque or rotational speed. An alternating magnetic field is generated in the drive by the drive currents. The alternating magnetic field causes movement of the drive. A first measurement signal and a second measurement signal are determined by a measurement device. The two measurement signals represent the first drive current and the second drive current. A field-producing direct-axis current component and a torque-producing quadrature-axis current component are determined as a function of the first and second measurement signals. In addition, an actual value of the movement variable is determined as a function of the measurement signals. At least one of the drive currents is generated with a variable test current component which forms a test pattern for checking the measurement device.

Abstract: A servomotor control system includes: an integrated control unit for integrally controlling servomotors; and servomotor units coupled with the integrated control unit and the servomotors. Each servomotor unit includes: a motor driver; a rotation detector of the servomotor; an original point detector for detecting an original point of the servomotor; a communication element for obtaining control information including rotation position instruction information from the integrated control unit; a rotation position calculator for calculating a current rotation position of the servomotor based on a rotation detection signal; a motor drive instruction element for outputting driving instruction information to the motor driver according to the control information and the current rotation position; and a current rotation position correction element for resetting the current rotation position to a predetermined original point when the original point detector detects the original point.

Abstract: Embodiments of the present disclosure provide a method that comprises, based upon receipt of a mode command, changing an operating mode of a fan motor controller of a fan to a serial port communication protocol, programming a memory of the fan motor controller with an operating parameter of the fan, and based upon receipt of a serial port command, changing the operating mode of the fan motor controller from the serial port communication protocol to another protocol.

Abstract: A variable-frequency drive that includes a DC power supply bus with a positive line and a negative line, and an inverter module powered by the DC bus for supplying a variable voltage to an electric load. The inverter includes a first DC/DC converter including output terminals connected in series on the positive line of the DC bus, a second DC/DC converter including input terminals connected between the positive line and the negative line of the DC bus, a filtering capacitor connected in parallel to the input terminals of the first converter and to the first output terminals of the second converter, and an electric power storage module connected in parallel to the second output terminals of the second converter.

Abstract: Methods and systems for controlling an electric motor are provided. The motor includes a plurality of windings. Each winding is coupled to a respective set of first and second switches. The first switch of each set of switches is simultaneously activated. Current flow through the plurality of windings is measured while the first switch of each set of switches is activated. The electric motor is controlled according to a first motor control method if the measured current is below a predetermined threshold. The electric motor is controlled according to a second motor control method if the measured current is above the predetermined threshold.

Abstract: When controlling an air compressor (13) for a pneumatic braking system on a large hybrid commercial vehicle (e.g., a bus, a package delivery truck, etc.), PID control of an air compressor motor (12) is employed during normal system operation such as when the motor shaft is spinning, and state machine control is employed during startup or upon a system disturbance such as a shaft seizure or stall. In this manner, stalling events that occurs due to PID control inability to correct for unexpected disturbances are mitigated by employing state machine control.

Abstract: A system and method of spread-spectrum fan control for an air-cooled system is provided for reducing the vibrational and acoustical noise associated with the air-cooled system. The method includes generating a first control signal that controls a blade-passing frequency of a first cooling fan and a second control signal that controls a blade-passing frequency of a second cooling fan, wherein the first and second control signals may be pulse width modulated (“PWM”) signals. One or more noise generators independently vary duty cycles for the first and second PWM signals within a range around respective first and second blade-passing frequency set points. As a result, the blade-passing frequencies for the first and second cooling fans are independently and randomly modulated within a range around the respective first and second blade-passing frequency set points.

Abstract: A compact field programmable gate array (FPGA)-based digital motor controller (102), a method, and a design structure are provided. The compact FPGA-based digital motor controller (102) includes a sensor interface (206) configured to receive sensor data from one or more sensors (104) and generate conditioned sensor data. The one or more sensors (104) provide position information for a DC brushless motor (108). The compact FPGA-based digital motor controller (102) also includes a commutation control (210) configured to create switching commands to control commutation for the DC brushless motor (108). The commutation control (210) generates commutation pulses from the conditioned sensor data of the sensor interface (206). The compact FPGA-based digital motor controller (102) also includes a time inverter (208) configured to receive the commutation pulses.

Abstract: A rotation speed detection circuit includes an internal clock generation portion which receives an input of a period signal whose period varies in accordance with rotation speed of a motor and generates an internal clock signal having a predetermined number of pulses in one period of the period signal, and an internal clock counter portion which counts the number of pulses of the internal clock signal for a predetermined period every one period of the period signal and delivers a count value thereof as a digital data signal.

Abstract: A winding switching apparatus includes a winding switching device and a drive circuit. The winding switching device is configured to switch a plurality of windings of an AC motor. The drive circuit is configured to control the winding switching device. The winding switching device includes a winding switch, a diode bridge, and a capacitor. The diode bridge includes a positive-side DC output terminal, a negative-side DC output terminal, and AC input terminals. The AC input terminals corresponds to respective phases of the AC motor. The positive-side and negative-side DC output terminals are respectively connected to positive-side and negative-side DC buses provided in an inverter. The AC input terminals are respectively connected to winding-switching terminals corresponding to the respective phases of the AC motor. The AC input terminals are respectively connected to phase terminals provided in the winding switch.

Abstract: An apparatus and method for driving a motor of an air conditioner are disclosed. A method for driving a motor of an air conditioner includes driving the motor in response to a predetermined speed command, sequentially detecting first and second mechanical angles in response to the speed command or a reference speed being spaced apart from the speed command by a predetermined range, calculating a maximum speed mechanical angle corresponding to a maximum speed ripple of the motor on the basis of the detected first and second mechanical angles, and compensating for load torque of the motor on the basis of the calculated the maximum speed mechanical angle. As a result, the speed ripple is decreased during the constant speed operation.

Abstract: A fan arrangement (20) has a fan (24) driven by an electric motor (22), also an apparatus for detecting the electrical power (PIST) consumed by the electric motor (22) during operation; an input apparatus (28) for inputting a desired rotation speed (nSOLL) of said electric motor (22); a converter (26) for converting said desired rotation speed (nSOLL) into a desired electrical power (PSOLL); and a controller (44), which regulates the control input controlling the electric motor (22) in such a way that the difference between the electrical power (PIST) consumed in operation and the desired electrical power (PSOLL) is reduced, in order thereby to improve the air output characteristic curve (49, 58) of the fan arrangement (20) at least in a portion of the overall operating range.

Abstract: A system for cooling a battery mounted on a vehicle using air within a vehicle, independently of the travelling state of the vehicle. The air within a vehicle compartment is guided to a battery mounted on a vehicle to cool the battery. A controller determines a basic fan speed v of the cooling fan based on a battery temperature and an ambient temperature. Further, the controller calculates an increment ?v of the fan speed in accordance with the vehicle speed and the degree of window opening and determines a final fan speed V according to V=v+?v, to drive the cooling fan. By controlling the fan speed to increase, it is possible to cool the battery even when the base pressure of the inlet-side static pressure of the cooling fan becomes negative pressure compared to when the windows are closed.

Abstract: A method for controlling a motor can suppress an influence of speed variation due to cogging of the motor. The method includes performing a preliminary drive process to output a first driving signal to the motor to move the mechanism, performing the preliminary drive process to output a second driving signal corresponding to a cogging period of the motor to the motor as well as output the first driving signal, to move the mechanism, determining parameters which include an output waveform and output timing of the second driving signal based on a speed of the mechanism in the preliminary drive process, and outputting the second driving signal according to the determined parameters to the motor as well as outputting the first driving signal to the motor in an actual drive process to perform predetermined processing by moving the mechanism.

Abstract: A system includes a speed control module, a repeatable component measuring module, and a repeatable component correcting module. The speed control module controls a speed of a motor based on an error signal generated based on a desired speed and back electromotive force. The error signal includes a repeatable component of noise. The repeatable component measuring module measures the repeatable component. The repeatable component correcting module corrects the repeatable component based on transfer characteristics of the speed control module and the motor and generates a corrected repeatable component.

Abstract: A circuit for controlling a rotation speed of a computer fan includes a control chip, a conversion circuit, a fan header, a first switch, and a second switch. When a first terminal of the first switch is connected to a second terminal of the first switch, and a first terminal of the second switch is connected to a second terminal of the second switch, the conversion circuit converts a control signal received from the control chip to a voltage signal, and outputs the voltage signal to a power pin of the fan header. When the first terminal of the first switch is connected to a third terminal of the first switch, and the first terminal of the second switch is connected to a third terminal of the second switch, a control pin of the fan header receives the control signal, the power pin receives power from a first power supply.

Abstract: A method and apparatus comprises a filter receiving an input voltage signal from a drive circuit, and a filter producing an output voltage signal with reduced resonance and transients. The amplitude of the output voltage signal is boosted using the filter.

Abstract: An automotive electric motor speed control system may include at least one electric motor adapted to cause a moveable element to move, a DC/DC power converter configured to output a voltage to the at least one electric motor that increases to a desired value and subsequently decreases to control the movement of the moveable element, and a controller configured to control the rate of voltage increase and voltage decrease output by the converter.

Abstract: A method for controlling the speed of an AC motor by means of an AC motor speed control having a plurality of capacitors operable to be selectively coupled in parallel electrical connection, the parallel coupled capacitors operable to be coupled in series electrical connection with the AC motor, the method comprising charging the capacitors up to substantially the same predetermined voltage prior to combining the capacitors in parallel electrical connection.

Abstract: The present disclosure is an apparatus for controlling movement of a decoy. The apparatus for controlling movement of a decoy may include a motor and a housing. The motor may cause movement of a decoy coupled to the motor to simulate movement of an animal. The apparatus for controlling movement of a decoy may include a shaft which couples to the motor and the decoy whereby the motor may cause axial rotation of the decoy.

Abstract: An integrated fan drive system for air-cooled heat exchangers. The integrated fan drive system has a high-torque, low speed permanent magnet motor having a rotatable shaft, a fan that is directly connected to the rotatable shaft, and a variable frequency drive device in electrical signal communication with the permanent magnet motor to control the rotational speed of the permanent magnet motor. The high-torque, permanent magnet motor comprises no more than two bearings in operative association with the shaft. The variable frequency drive device has a variable frequency controller that has an input for receiving AC power and an output for providing electrical signals that control the operational speed of high-torque, permanent magnet motor. The variable frequency drive device also includes a user interface in electronic data signal communication with the variable frequency controller to allow a user to input motor speed control data. Other embodiments of the invention are described herein.

Abstract: In a motor speed controller, feedback control is implemented at a gain independent of the target rotational speed ?T while the increase in the circuit size or processing load is reduced. The rotational speed ? of the motor is controlled on the basis of a pulse signal in which a pulse period ?P varies in inverse proportion to ?. A count clock generation circuit varies the clock frequency FC in proportion to ?T. The pulse period measurement section counts the count clock CLK during ?P at the present ? and determines a measured count value C. The feedback filter inputs, as an error signal Ve, the difference between C and a target count value CN that corresponds to ?T, and generates an instruction signal to provide compensation for Ve. The feedback filter scales the instruction signal at a scaling factor that is proportional to ?T.

Abstract: A three-phase bridge rectifier circuit (BRC) connectable to an AC voltage source (ACVS) via input lines (151, 153, 155) and a load (109) via output lines (157, 159). ACVS (102, 104, 106) supplies BRC (100) with AC voltage waveforms that differ in phase. The BRC includes a three-phase bridge rectifier circuit comprised of field effect transistors (FET) and gate drive circuits (GDC). Each GDC (101a, 103a, 101b, 103b, 101c, 103c) supplies a voltage to a gate of a respective FET (110, 112, 114, 116, 118, 120) for switching the FET to its “on” state at a certain time. The BRC further includes a diode (190, 128, 198, 148, 113, 168) connected between a drain of each FET and a terminal of each GDC. The BRC can further include voltage divider circuits (192/188, 130/140, 107/196, 150/160, 115/111, 170/180) and/or voltage clamping devices (121, 131, 123, 133, 125, 135).

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: An apparatus, system, and method are disclosed for controlling fan speed in a power supply. The apparatus measures input power to the power supply and measures the output power provided by the power supply over an interval. The apparatus determines values for the input power and output power and, using the two, determines how much power has been dissipated in the power supply. Power dissipation values are associated with particular fan speeds, and the apparatus adjusts the speed of the fan in the power supply based on how much power was dissipated during the interval. Increasing levels of power dissipation increases the fan speed, and decreasing levels of power dissipation decrease the fan speed.

Abstract: A model train control system providing a more realistic modeling of the movement, sound, smoke, and lighting effects of a model train is disclosed. A number of dynamic inputs are used to control such effects. Novel features include providing a dynamic variable speed compensator, a dynamic engine load calculator, automatic dynamic momentum, an adjustable train brake, spectrum control, a velocity controller, pressure sensitive effects, a voice activated dispatcher system, a train location and information reporter network, two digit addressing, a traffic control system, accessory control, a model train Central Control Module, and removable memory modules.

Abstract: An energy conservation system that realizes optimized power demand control for alternating current electrical motors equipped with variable frequency drives is implemented by switching an electrical motor via bypass systems from a variable frequency and speed drive mode of operation to a constant frequency and speed drive mode of operation and from a constant frequency and speed drive mode of operation to a variable frequency and speed drive mode of operation. The switching from one mode of operation to another is automatically executed based on the comparative analysis of historical and current trends of the electrical motor actual power demand at variable and constant speed drive modes of operation at various loads. The system optimizes the electrical motor operation by selecting the mode with the lower magnitude of cumulative power demand for the motor and motor drive at a given motor load.

Abstract: A motor controller capable of effectively utilizing electrical energy accumulated in a capacitor and achieving a reduction in capacitance of the capacitor. The motor controller includes a converter that receives an input AC voltage and performs AC-to-DC power conversion thereon, an inverter that receives DC power and performs DC-to-AC conversion thereon, and a capacitor and a charging/discharging control circuit connected in parallel with a DC link between the converter and the inverter. Electrical energy is supplied from the capacitor to the DC link via the charging/discharging control circuit. The charging/discharging control circuit has a circuit for discharging electrical energy accumulated in the capacitor and for stepping up a voltage of the capacitor when discharging the electrical energy.

Abstract: The present invention relates to a method of controlling the speed of rotation of a piezoelectric motor comprising at least one step of determining the variation of the speed of rotation as a function of the frequency of the excitation voltages of the piezoelectric motor for the actual temperature of the piezoelectric material.

Abstract: An aperture closure member control arrangement includes a disc which rotates as the aperture closure member moves. The disc has a ring of teeth. A sensor, such as a Hall effect sensor and permanent magnet, detect the passage of teeth as a cyclic waveform of amplitude and frequency determined by the spacing of the teeth, and the speed of rotation of the disc. An irregularity in the form of a missing tooth creates an irregularity in the output of the sensor, in the form of a pulse of greater amplitude and lower frequency. Accordingly, pulses from the irregularity can be discriminated and counted to provide a coarse indication of position, or pulses from the teeth can be counted, to provide a fine indication.

Abstract: An integrated fan drive system for a cooling tower comprising a high-torque, low speed permanent magnet motor having a rotatable shaft, a fan comprising a hub that is directly connected to the rotatable shaft and a plurality of fan blades that are attached to the hub, and a variable frequency drive device in electrical signal communication with the permanent magnet motor to control the rotational speed of the permanent magnet motor. The high-torque, permanent magnet motor comprises no more than two bearings in operative association with the shaft. The variable frequency drive device has a variable frequency controller that has an input for receiving AC power and an output for providing electrical signals that control the operational speed of high-torque, permanent magnet motor. The variable frequency drive device also includes a user interface in electronic data signal communication with the variable frequency controller to allow a user to input motor speed control data.

Abstract: A heat dissipation device has a main controller and a fan module having a motor coil, a connection interface, a PWM driving circuit and a fan monitor chip. The connection interface has a control pin, an error report pin, a power supply pin and a ground pin. The control pin receiving a control signal. The PWM driving circuit adjusts current magnitude and current direction of the motor coil to drive the fan module. The fan monitor chip is connected to the connection interface and the PWM driving circuit, receives the control signal, generates and sends PWM signals to the PWM driving circuit according to the control signal and sends an acknowledgement signal via the control pin after receiving the control signal. The main controller can check if the control signal is correctly received based on the acknowledge signal.