Abstract: The present invention provides an improved transformer (20), which broadly includes: a substrate (21) having first and second surfaces (22, 23); a first board (24) mounted on the substrate first surface; a second board (25) mounted on the substrate second surface; the boards being identical to one another and being mounted on the respective proximate substrate surfaces as mirror images of one another; each of the boards having a plurality of dielectric layers with electrically-conductive sheet windings (35, 36, 37, 38) embedded therein; and an assembled core (26, 28) operatively arranged to provide a path for magnetic flux attributable to a current in the some of the windings. Third and fourth boards (71, 72) may be piggy-backed onto the first and second boards, respectively, to selectively vary the properties of the transformer.

Abstract: A drive signal generation circuit generates drive signals that control ON and OFF states of transistors of a H-bridge circuit, in accordance with a target value of torque. A driver circuit alternatively turns ON and OFF high side transistors, and low side transistors of the H-bridge circuit, based on the drive signals outputted from the drive signal generation circuit. The driver circuit immediately turns OFF the high side transistors, when an instruction is issued to stop a motor, and after a predetermined delay time ?d has elapsed, turns OFF the low side transistors.

Abstract: At the time of an occurrence of failures of an inverter, both of two switching elements of the buck-boost converter are switched on so that electric charge is discharged from the smoothing capacitor that smoothes voltage between terminals of the inverter regardless of whether a collision of a vehicle occurs or not (S110, S120). Thus, the electric charge can be securely discharged from the smoothing capacitor at the time of an occurrence of the collision of the vehicle even when at least one of a motor and the inverter is damaged. Also, the electric charge can be securely discharged from the smoothing capacitor at the time of the occurrence of the failures of the inverter.

Abstract: A vehicle (100) includes a motor generator (MG) and an inverter (14) driving the motor generator (MG). A power source apparatus for the vehicle includes a battery (B) as an electric storage device, a step-up converter (12) stepping up a voltage of the electric storage device and supplying it to the inverter, and a controller (30) indicating a target step-up voltage in accordance with a target state of operation of the motor generator (MG) to the step-up converter (12). If it is determined that a current operation state signal of the motor generator (MG) is abnormal, the controller (30) increases the target step-up voltage to a maximum value. Preferably, the vehicle (100) further includes a resolver (20) detecting rotation speed of a rotor of motor generator (MG). The controller (30) determines that the operation state signal is abnormal if an output of the resolver (20) does not satisfy a prescribed condition.

Abstract: An AC/DC converting circuit, has a full-bridge rectifier having two input terminals and two output terminals, a first capacitor, a second capacitor, an electronic switch having a control terminal, a trigger circuit having an input terminal and an output terminal, and a detecting circuit having an input terminal and an output terminal.

Abstract: A variable magnetic flux motor drive system includes: a variable magnetic flux motor having a variable magnet which is a low-coercive permanent magnet; an inverter that drives the variable magnetic flux motor 1; an inverter as a magnetization unit which supplies a magnetization current for controlling a magnetic flux of the variable magnet; and a boosting unit boosting an input DC voltage to a predetermined target value to output it to the inverter. The variable magnetic flux motor drive system makes it possible to achieve size reduction and high efficiency, while securing a voltage required for supplying a magnetization current when controlling the magnetic flux of the variable magnet.

Abstract: A motor drive control device including a power supply converter that is connected to an alternating-current power supply, a voltage detector that detects a direct-current voltage of the power supply converter, an inverter that is connected to a motor, and an energy storage device that is connected to a direct-current bus that connects the power supply converter and the inverter.

Abstract: A power supply system is provided with a plurality of driving motors, a power converter, and a plurality of power supplies which supply the driving motors with power and have different output voltages. Each power supply is connected with at least one driving motor through the power converter and with at least one driving motor through a path which does not include the power converter.

Abstract: In an AC-input type brushless DC motor, a current control circuit controls an average current of an inverter circuit, a current indication circuit makes addition or subtraction, with respect to a reference current value, to the average current to be supplied to the inverter circuit such that the average current falls into a correlation indicated by a correlation indication circuit. The foregoing structure allows setting speed-torque characteristics of the brushless DC motor such that the torque increases at a higher rpm of the motor. The characteristics are good for driving a fan.

Abstract: The motor of the motor apparatus includes a rotor including a plurality of magnetic poles and a stator formed with tooth portions radially extending with a pitch equal to 5/6 times or 7/6 times a pole pitch of the rotor. Each tooth portion is formed with a brim portion circumferentially extending from both circumferential sides of the tooth portion. The phase ends of the stator winding are connected respectively to the AC ends. The DC power supply is connected between one of the DC ends and the neutral point of the stator winding. The control section controls the multi-phase inverter such that a multi-phase AC current containing a DC component flows through the stator winding. The circumferential width of the brim portion is smaller than or equal to 0.75 times a cross-sectional size of the electric wires constituting the stator winding.

Abstract: An electric energy exchange system between at least one motor-generator system and at least one storage member determining a continuous storage voltage between two branches of a bus circuit on which are connected in parallel a DC/DC converter, a filtering capacity, and a DC/AC converter connected on at least one motor-generator system. The system includes at least one thyristor connected as a bypass on the positive bus between the storage member and the output of the converter-voltage raiser to short-cut the converter, and a thyristor priming device to, based on the required voltage at the filtering capacity, determine at least in discharge the shorting of the converter-voltage raiser with direct passage of the current through the thyristor as long as the voltage of the filtering capacity, which is substantially equal to the storage member voltage, is sufficient for the electric machines to provide requested torque.

Abstract: An electric drive unit for a water-bearing domestic appliance having a converter to provide a supply voltage from a multiphase voltage system; a control device to control the converter in order to operate a first electric motor connected to the multiphase voltage system; a load-current-carrying DC link arranged upstream of the converter; and an electrical device connected to at least part of the multiphase voltage system or the load-current-carrying DC link via a connection device, wherein the electrical device has a second electric to operate a hydraulic pump and/or a blower and/or a valve.

Abstract: Embodiments of an apparatus to increase the power efficiency of an electric motor load have been presented. In one embodiment, the apparatus includes a parameter detection circuit coupled to the electric motor load to detect one or more parameters of the electric motor load. Furthermore, the apparatus may include a power management controller coupled to the parameter detection circuit to receive the one or more parameters and to scale a voltage supply to the electric motor load in response to the parameters.

Abstract: [Task] A high-speed driving is possible, a utilization of a power supply having a low voltage is possible, and a regeneration is easy to be carried out. [Means to Solve the Task] A first buck-boost chopper portion is provided on an output side of a battery 10 to boost a voltage across battery 10 during a drive of a motor, a second buck-boost chopper portion is provided on an output side of the first buck-boost chopper portion to boost the voltage from an inverter portion 20 during a regeneration, inverter portion 20 of a 120-degree conduction current source inverter is provided on the output side of the second buck-boost chopper portion, and a motor 38 is provided on an output side of inverter portion 20.

Abstract: An electric motor control device includes an inverter that supplies an output of a primary-side DC power supply to an electric motor to control driving of the electric motor; a converter that includes a voltage increasing power supply device that increases a voltage of the primary-side DC power supply to supply the inverter with the increased voltage as a secondary voltage, and a regenerative power supply device that reversely supplies regenerative power from the inverter to the primary-side DC power supply; a secondary-side target voltage determination unit; a converter control unit; and an electric motor control unit.

Abstract: According to some preferred embodiments of the present invention, a motor driving circuit includes a phase detection circuit configured to detect a rotation phase of a motor and output a phase detection signal, a first amplifier configured to amplify the phase detection signal and output an amplified detection signal, and a second amplifier configured to amplify the amplified detection signal in accordance with a power supply voltage and output a driving signal to the motor. The motor driving circuit is further provided with a controlling circuit configured to detect the power supply voltage and increase/decrease amplitude of the amplified detection signal outputted from the first amplifier in response to an increase/decrease of the detected power supply voltage, whereby heat generation and noise generation can be restrained, irrespective of the increase/decrease of the power supply voltage.

Abstract: A vehicle includes: an engine driven with gasoline; a lid member opening/closing an opening of an accommodation room that accommodates a nozzle receiving unit when gasoline is supplied; a rotating electric machine driven on electric power; a charging/power feeding unit receiving electric power; a lid member opening/closing an opening of an accommodation room accommodating a charging/power feeding unit; and an open/close control mechanism setting the other of the lid member and the lid member in the closed position when one of the lid member and the lid member is set in the open position.

Abstract: A fan includes a motor control device which is electrically connected with a motor and an alternating current power source. The motor control device includes a converting circuit, a power factor correction circuit and a motor controlling circuit. The voltage of the alternating current power source is converted to be direct current voltage by the converting circuit and the power factor correction circuit, and then the direct current voltage is outputted to the motor control circuit. The motor controlling circuit generates a driving signal in accordance with the direct current voltage for driving the motor to operate.

Abstract: The present invention relates to a power generating apparatus and method for assisting an engine, capable of supplying auxiliary power to an engine transmission shaft when the engine is transmitting power to the engine transmission shaft via a gearbox. The power generating apparatus comprises: a power supply unit for providing a high voltage power source; a driver for converting the high voltage power source into a driving power source and transmitting same; and a direct-current motor for converting the driving power source transmitted by the driver into the auxiliary power to be transmitted to the engine transmission shaft; wherein the rotational speed of the direct-current motor driving the engine transmission shaft is enabled to be higher than that of the engine driving the engine transmission shaft, so as to supply the auxiliary power to the engine transmission shaft.

Abstract: Devices and methods for performing dynamic sampling of a back electromotive force (BEMF) measurement are provided. A device has hardware, including a voice coil motor (VCM) for receiving a VCM command signal and a correction circuit, for obtaining the VCM command signal and a coil voltage measurement from the hardware, where the correction circuit removes a transient voltage measurement due to a change in the VCM command signal from the coil voltage measurement and outputs an estimated BEMF measurement.

Abstract: A controller calculates a total power fluctuation including a power fluctuation on a first unit and a power fluctuation on a second unit. The controller estimate a voltage fluctuation of the system voltage based on the total power fluctuation. Then, the controller calculates a control amount for a voltage converter by reflecting the estimated voltage fluctuation. The estimated voltage fluctuation can be used to correct a feed-forward control amount. As a result, a voltage stabilizing control is performed based on the estimated voltage fluctuation which could be occurred in response to the total power fluctuation if no stabilizing control is performed. Thereby, the stability of the system voltage can be improved without using a large size smoothing capacitor.

Abstract: An intelligent auxiliary power supply system for supplying power to a load such as a furnace or air handler using a rechargeable power source. An intelligent controller determines appropriate periods for switching to auxiliary power, thus allowing the user to realize increased energy related cost savings. A plurality of sensors including a current transducer, an indoor and outdoor temperature sensor, and a clock transmit information to the intelligent controller. Implementing user configured algorithms, the intelligent controller continuously compares information transmitted from said sensors and said load, to information inputted by the user via an electronic device to determine the appropriate power configuration. A remote electronic device may also be connected to the system, allowing the user to control the system while not in close proximity to said system and also allowing the user's energy provider to send requests to switch to auxiliary power.

Abstract: There is provided an automatic transmission control apparatus that secures the safety of a motor drive, even in the case where an abnormality exists in a unit that detects a voltage supplied to a motor control apparatus, and that neither deteriorates the controllability of the motor drive nor erroneously operates the transmission mechanism of the automatic transmission. An automatic transmission control apparatus according to the present invention is provided with a voltage determination unit that determines which one of a voltage detected by a control apparatus voltage detection unit and a voltage detected by a motor voltage detection unit is utilized as a duty reference voltage; the motor control apparatus controls the motor, based on a motor drive duty that a drive duty calculation unit calculates by use of the voltage determined by the voltage determination unit.

Abstract: A synchronous electrical machine comprising a plurality of phases, detecting means arranged to detect a fault in at least one of the phases of the synchronous electrical machine, isolating means arranged to isolate the at least one phase of the synchronous electrical machine with the fault, phase shift means arranged to produce a controlled phase shift between the voltage and the current within the remaining phases of the synchronous electrical machine to adjust the phase angle and magnitude of the second harmonic powers produced by the remaining phases of the synchronous electrical machine such that the vector sum of the second harmonic power vectors of the remaining phases of the synchronous electrical machine is zero.

Abstract: A boost power module and an inverter form a semiconductor module. A smoothing capacitor is arranged outside the semiconductor module. A bus bar forming a power supply line is divided into bus bars, between which a lead member extending outward from the semiconductor module is coupled. The lead member has an electric contact with one of terminals of the capacitor arranged outside the semiconductor module. A bus bar forming an earth line is divided into bus bars, between which a lead member extending outward from the semiconductor module is coupled. The lead member has an electric contact with the other terminal of capacitor.

Abstract: In an AC motor driving circuit, a current-type rectifier circuit having a filter circuit and first bidirectional switches bridge-connected to the filter circuit is provided in an output of an AC power supply. An AC motor is connected to an output of the rectifier circuit through a voltage-type inverter. One terminal of each of second bidirectional switches is connected to corresponding one of output terminals of the current-type rectifier circuit. The other terminals of the second bidirectional switches are collectively connected to one terminal of a series circuit having a DC power supply and a reactor. The other terminal of the series circuit is connected to one output terminal of the current-type rectifier circuit. With this configuration, a large capacitor for a DC link can be dispensed with, so that a reduction in circuit size and weight can be attained.

Abstract: A motor control device for controlling rotation of a brushless DC motor of a ceiling fan includes a receiver unit that receives an input signal and outputs a command signal, a magnetic sensor unit for detecting a magnetic pole variation of the brushless DC motor so as to generate a position signal, a processing unit that is electrically connected to the receiver unit and the magnetic sensor unit and that generates a control signal, a motor drive unit that is electrically connected to the processing unit and the brushless DC motor and that generates a drive signal for driving the brushless DC motor, an AC to DC converter unit that rectifies and filters a grid power to generate a first DC power for the motor drive unit, and a DC to DC converter unit that is electrically connected to the aforementioned units and that generates a second DC power.

Abstract: In a vehicle control system that includes an engine, a first rotary electric machine, a second rotary electric machine and a transmission, a control unit includes a shift state acquisition module that acquires a shift state of a vehicle; a stepped-up voltage reduction permission module that determines whether reduction of a system voltage is permitted on the basis of the acquired shift state; a stepped-up voltage reduction execution module that reduces the system voltage to a predetermined upper limit voltage when reduction of the system voltage is permitted; and a drive control module that controls operations of a converter and inverter to thereby control the first rotary electric machine and the second rotary electric machine.

Abstract: The present invention particularly relates to a hand-held sanding machine with an outer housing (1), a tool shaft (2) and a brushless electric drive motor. In the present invention, the rotor of the drive motor is fastened to the tool shaft (2) of the sanding machine, and the stator (6) is positioned in the outer housing (1). The present invention also relates to a control method for an electric sanding machine.

Abstract: The present invention provides a generator motor driving device that can promptly perform discharging of charges from the capacitor during a maintenance operation, and a capacitor discharge method to be implemented in the generator motor driving device. Power is supplied from the capacitor to the generator motor being driven by the engine, and the generator motor is driven, with the engine as a load. Rated constant current control is performed on the generator motor, and rated constant voltage control is performed on the booster, until the capacitor voltage decreases to a first voltage. After the capacitor voltage decreases to the first voltage, the rated constant current control is performed on the generator motor, and voltage control is performed on the booster to maintain a predetermined ratio between the capacitor voltage and the booster output voltage to be output to the driver, until the capacitor voltage decreases to a second voltage that is lower than the first voltage.

Abstract: An object is to obtain an electric vehicle controller capable of reducing a total sum of losses of an AD motor and losses of a main circuit. In a vector-control-command-value calculating unit, according to a torque command T*, a DC-voltage command value EFCR and a magnetic-flux command value F2R for which a total sum of losses of an AD motor and losses of a second main circuit is minimized is calculated and selected. The vector-control-command-value calculating unit outputs the magnetic-flux command value F2R to a vector control unit, and outputs the DC-voltage command value EFCR to a converter control unit.

Abstract: There is provided an inverter device capable of simplifying the circuit structure, lowering the cast, and downsizing of the device. The inverter device detects a switching change of an inverter by a pulse and is equipped with a pulse signal detector capable of detecting a motor residual voltage or a phase and a detector for detecting a residual voltage or a phase. The inverter device includes a voltage detector, a circuit for detecting a pulse signal based on a comparison between a phase voltage detection value per one phase output from the voltage detector and a first reference voltage value, a circuit for detecting a line residual voltage based on phase voltage detection values of two phases output from the voltage detector, and a circuit for detecting a line phase based on a comparison between the line residual voltage and a second reference voltage value.

Abstract: Specific anomalies and details of failures as well as measures thereagainst are described that might possibly occur in electric power converters that drive and control permanent-magnet synchronous motors. An electric power converter capable of stable operation has a protective function of taking proper measures against such failures that might possibly occur.

Abstract: A method of controlling a hybrid construction machine capable of preventing a system from being rendered inoperative without increasing a capacitance of a capacitor and of inhibiting delay of a swing operation relative to an operation command at the time of swing operation, and the hybrid construction machine are provided. For this purpose, at the time of discharge of the capacitor, actual torque command values are respectively generated by referring to an assist torque limit value corresponding to capacitor voltage of a generator motor and a swing power running torque limit value corresponding to the capacitor voltage of a swing motor, as well as, at the time of charge of the capacitor, an actual target output value of the generator motor is generated.

Abstract: A ventilator includes a base, a drive device disposed on the base, an impeller coupled to the drive device and driven by the drive device, and a cover assembled with the base to define a closed area between the cover and the base for receiving a first circuit board therein, wherein when an AC power source is input to the first circuit board to be converted, a DC power source is output to drive the drive device.

Abstract: A drive circuit for a motor having a plurality of phases, comprising an input for a DC signal and a plurality of phase outputs, the circuit being arranged to provide at each of the phase outputs, in use, current to one phase of the motor, in which there is provided a converter for each phase output, each converter being arranged to take as an input a DC signal and output an signal having an AC component with a higher voltage magnitude than that of the DC signal input to the converter. Typically, the converters comprise ?uk converters.

Abstract: A target power value determining unit (200) determines target power values Pc1* and Pc2* such that a sum ?Pc* of target load powers as a sum of target load power Pc1* and target load power Pc2* does not exceed a sum ?Win of allowable charging powers and a sum ?Wout of allowable discharging powers. In accordance with the generated target load power values Pc1* and Pc2*, switching commands PWM1 and PWM2 are generated. Consequently, an inverter executes a power conversion operation such that the powers exchanged between a main line ML and motor generators attain to the target load power values Pc1* and Pc2*, respectively.

Abstract: A trigger switch performs speed control of a motor according to a pull-in amount of a trigger. A wiring path for lead wires connects the trigger switch and an auxiliary device. The wiring path is formed in an insulating wall. The insulating wall isolates a pair of power supply terminals, each connected to a power supply, from each other.

Abstract: A control apparatus for an electric railcar includes an inverter that exchanges power with an AC rotating machine, a filter capacitor connected in parallel to a DC side of the inverter, a filter reactor provided between the filter capacitor and an overhead line, an overhead line voltage measuring instrument that measures a voltage value of the overhead line, a voltage increase detection unit that senses an amount of voltage increase occurring when, with an overhead line voltage being supplied, the overhead line voltage goes beyond a reference voltage value and rises at a rate equal to or higher than that by a predetermined time constant.

Abstract: Cathode-anode voltage across free-wheeling diodes in an active rectifier is used in the determination of switching points when the free-wheeling diode is forward biased. Hysteretic switching is accomplished through the selection of conductive and non-conductive switching threshold. The switching thresholds are further selected to prevent voltage oscillations at zero current crossings and reduce delays during deactivation to prevent cross-conduction.

Abstract: Taught herein is a controller for a direct current brushless motor connected to a high voltage control system, comprising a microprocessor and an input/output interface circuit connected between the high voltage control system and the microprocessor; wherein the input/output interface circuit is a step-down circuit for transforming a high voltage control signal into a low-voltage control signal. The controller enables the high voltage control system to cooperate with motor, therefore a user is not necessary to design a new high voltage control system when replacing the conventional AC motor with the DC brushless motor, which saves time, and reduces cost.

Abstract: A system is disclosed for driving a DC motor (15) under conditions of a controlled average current. An inductive element may be arranged for connection in series with the DC motor. A switch (14) is preferably coupled to the inductive element for connecting and disconnecting a terminal of the inductive element from the voltage source. A diode may be arranged for connection in parallel with a combination of the inductive element and the DC motor arranged in series, with the appropriate polarity so that current circulating through the inductive element circulates through the diode when the switch disconnects the terminal from the voltage source. A capacitor is arranged for connection in parallel with the motor, for limiting a resulting voltage over the motor or for storing charge depending on the embodiment of the invention. A device for measuring a current through the motor is provided, and a device (13) for controlling operation of the switch dependent upon the measured current in the motor is also provided.

Abstract: A rotating electrical machine control system includes a frequency converting portion that is interposed between a rotating electrical machine for driving a vehicle and a DC power source for supplying electric power to the rotating electrical machine, and that converts an output of the DC power source to an AC output at least during a powering operation of the rotating electrical machine; a voltage converting portion that is interposed between the DC power source and the frequency converting portion, and that boosts the output of the DC power source based on a boost command value which is set according to a target torque and a rotational speed of the rotating electrical machine; and a control portion for controlling the frequency converting portion and the voltage converting portion.

Abstract: A power supply system is provided for supplying power to a first drive device and a second drive device functioning as a drive source of a moving body. A fuel cell and a storage battery device are connected via a power conversion device. The fuel cell can supply power to the first drive device and the storage battery device can supply power to the second drive device, respectively, without using the power conversion device. When an output request from the moving body is a normal output request, power is supplied to each of the drive devices by the fuel cell and the storage battery device, respectively. Only when power to be supplied to the first drive device as in the output request from the moving body is greater than an amount of power that can be generated by the fuel cell, that power supply from the storage battery device to the first drive device via the power conversion device is permitted.

Abstract: Systems and methods relating to a boosting rectifier and feeder motor drive circuit are provided. The circuit may be used to produce a regulated DC supply voltage from a variable input AC line voltage, chop the DC supply voltage and deliver a pulse width modulated motor voltage to a wire feed motor in the wire drive assembly. One embodiment relates to elimination of undesirable wire feeder inconsistencies due to motor loading conditions, distance between the primary power source and the wire feeder, and so forth. In certain embodiments, the circuit may contain power factor correction circuitry, which may reduce the size of circuit components due to increased efficiency. Current paths through the circuit during the positive and negative half cycles of the AC input voltage are provided. Exemplary controller logic that may be used to control the operation of the boosting rectifier and feeder motor drive circuit is provided.

Abstract: A rotating electrical machine control system includes a frequency converting portion that is interposed between a rotating electrical machine for driving a vehicle and a DC power source for supplying electric power to the rotating electrical machine, and that converts an output of the DC power source to an AC output at least during powering operation of the rotating electrical machine; a voltage converting portion that is interposed between the DC power source and the frequency converting portion, and that boosts the output of the DC power source based on a boost command value which is set according to a target torque and a rotational speed of the rotating electrical machine; and a control portion for controlling the frequency converting portion and the voltage converting portion.

Abstract: An electric power supply system, equipped on a mobile body to supply electric power to a drive apparatus that functions as a drive source of the mobile body, that includes a first power source apparatus that generates and supplies electric power to the drive apparatus, a second power source apparatus provided separately from the first power source apparatus and that supplies electric power to the drive apparatus, an insulation type converter provided between an electric power supply section including at least one of the first power source apparatus and the second power source apparatus, and a mobile body drive section including the drive apparatus, and ensuring insulation between these sections while transmitting electric power from the electric power supply section to the mobile body drive section. An increase in the supply voltage and adequate insulation performance can both be achieved when supplying power to a drive apparatus.

Abstract: An EPC connected between a three phase motor and a battery fixes a voltage of the V phase of the three phase motor to a voltage potential of a positive electrode of the battery. A converter unit is placed for each of the U and W phases of the three phase motor. Each of the converter units has a chopper circuit part and a capacitor Each of the converter units converts the voltage of the battery to a desired voltage. The voltage of each of V and W phases is adjusted until the voltage of being twice of the voltage of the battery based on the voltage potential at the positive electrode of the battery as a reference voltage. This makes it possible to adjust the absolute value of a line voltage between V and W phases until the voltage of the battery as an upper limit voltage.

Abstract: A dual power supply type brushless fan motor speed control device for controlling the speed of the fan motor of a ceiling fan formed of a DC power supply circuit unit, a central processing unit, a medium and high speed power supply control unit, a low-speed power supply control unit, a back electromotive force detection circuit unit and three drive output control circuit units.

Abstract: A motor drive circuit for driving a single-phase brushless DC motor includes a rotatably supported magnet rotor having magnetic poles, a stator core provided with slots and teeth, the teeth being arranged to face the magnet rotor, and a motor coil held in the slots. The single-phase brushless DC motor drive circuit further includes a plurality of magnetic pole position detectors for outputting detection signals indicative of magnetic pole positions of the magnet rotor, a rotation direction instruction circuit for issuing an instruct of a rotation direction of the magnet rotor, a selector circuit for selectively outputting the detection signals of the magnetic pole position detectors, a switching circuit for driving the motor coil and a control circuit for, based on the selectively outputted detection signals from the selector circuit, controlling the switching circuit to thereby control a direction and a magnitude of current flowing through the motor coil.