Abstract: A fan motor includes a motor having a shaft, a fan, and a fan fixing section for rigidly connecting the fan to the shaft. The fan has a first mounting face for the fan to be integrated with the motor. The fan fixing section has a fan mounting plate mounted to an end of the shaft and including a second mounting face in a radial direction, and an elastic plate having elastic force. The first mounting face is connected to the second mounting face via the elastic plate.

Abstract: An aircraft power generating assembly having a mechanical gear transmission, and an electric machine integrated in the mechanical transmission; the electric machine having a stator connected directly to a fixed frame of the mechanical transmission, and a rotor surrounding and rotated by a rotary shaft of the mechanical transmission; and the opposite ends of the rotary shaft being connected to respective further rotary input/output shafts.

Abstract: A motor that is operable in response to an external power supply includes a stator core that is electrically connected to the external power supply and a rotor core positioned adjacent the stator core and rotatable about an axis in response to power being delivered to the stator core by the external power supply. A first encasement member is formed around the stator core to define a cavity and a second encasement member is formed around the rotor core and is sized such that at least a portion of the second encasement member and rotor core is disposed within the cavity. A quantity of coolant is disposed within the cavity.

Abstract: A method of making an electric motor includes installing a plurality of hairpin coils in a plurality of slots, wherein the plurality of hairpin coils comprise a first hairpin coil and a second hairpin coil, the first hairpin coil comprising a first end and the second hairpin coil comprising a second end. The method further includes inserting the first and second ends into a void of an electrically conductive coupler to electrically connect the first and second ends; and placing the insulation cap over the coupler so as to protect the coupler from contacting other electric conductive materials.

Abstract: A method for securing a motor housing to a motor assembly is provided. One application of the method creates a motor housing to secure and protect a motor assembly. A flat metal sheet is shaped, so that deformable ends of the sheet are incrementally rolled to form a split annulus approximating the outer circumference of a motor assembly. Once the split annulus is formed, the ends are elastically deformed to facilitate inserting the motor into a hollow portion of the split annulus. After the motor is inserted, the ends may be joined by welding one to the other. This type of housing secures the motor assembly through a crimping force applied by the housing. Alternately, the ends may be welded together and to the motor assembly itself, thereby forming a strong support structure between the housing and the motor assembly.

Abstract: In a method for manufacturing a helically wound alternator core, stamping an electrical steel strip to create a lamination strip having a back-iron and projecting teeth. The lamination strip is helically wound by bending to form the helically wound alternator core. The core is then welded. Thereafter the helically wound welded alternator core is annealed.

Abstract: A permanent magnet includes two or more separate permanent magnet pieces each having a rectangular parallelepiped shape with a fractured surface formed when a permanent magnet block is fractured. The separate permanent magnet pieces include a first separate permanent magnet piece and a second separate permanent magnet piece. At the time when the permanent magnet block is fractured, the first and second separate permanent magnet pieces are adjacently located and a first fractured surface of the first separate permanent magnet piece and a second fractured surface of the second separate permanent magnet piece are adjacent to each other. The permanent magnet is configured such that the first fractured surface of the first separate permanent magnet piece and the second fractured surface of the second separate permanent magnet piece are located in positions out of contact with each other.

Abstract: Provided is a motor comprising: a stator equipped with a coil basket, which is a distributed winding coil that uses flat wire, and a stator core; and a rotor with a central shaft. The motor is characterized in that: the coil end at one end of the coil basket has bent sections that are bent on the rotor side in relation to wire sections inside slots of the stator core; and a lower-side concentric section and horizontal sections, which comprise the coil end at the other end, are positioned further toward the shaft center side of the rotor than the inner peripheral surface of the teeth; and the coil end at one end and the coil end at the other end comprise five flat wires that are lap wound in a flatwise direction.

Abstract: A driving apparatus includes a first electrical rotating machine, a second electrical rotating machine, a first resolver, and a second resolver. The first resolver is configured to detect a rotation angle of the first electrical rotating machine. The second resolver is configured to detect a rotation angle of the second electrical rotating machine. The first and second electrical rotating machines and the first and second resolvers are coaxially disposed inside a casing. The first resolver and the second resolver are provided between the first electrical rotating machine and the second electrical rotating machine.

Abstract: A stepper motor is provided in which a permanent ring magnet is sandwiched in an outer part of the stator winding assembly located far from the gap between rotor and stator teeth, so that magnetic flux in the gap is dominated by the Ampere-turns of energized stator coils and therefore more easily controlled for reduced vibration at low stepping speeds. The rotor need not contain any permanent disk magnet. If one is provided, it can be completely embedded within the rotor and merely supplement the primary flux from the stator to enhance torque. In most cases, where the rotor lacks any permanent magnet, the motor's axial shaft can have a larger diameter and may, together with the rotor, form a linear actuator.

Abstract: Disclosed are driving control methods and circuits for quasi-resonant control of a main power switch of a switching power supply. In one embodiment, a driving control circuit can include: (i) a clamp circuit coupled to a gate of the main power switch, where the clamp circuit is configured to clamp a voltage of the gate to a clamping voltage that is greater than a threshold voltage of the main power switch; (ii) a valley voltage detection circuit configured to activate a valley control signal when a drain-source voltage of the main power switch is at a resonance valley level; and (iii) a source voltage control circuit configured to reduce a voltage of a source of the main power switch to turn on the main power switch in response to the valley control signal being activated.

Abstract: A controller for a power converter compares a voltage sense signal to a first reference and compares a current sense signal to a current sense signal. The voltage sense signal is representative of an input voltage of the power converter. The current sense signal is representative of a current through the power converter. A slope of the voltage sense signal is measured over time. An edge detection is asserted by the controller when (1) the voltage sense signal is larger than the first reference, (2) the current sense signal is lower than the second reference, and (3) the slope is a negative slope.

Abstract: The present invention discloses precharge circuits and methods for DC-DC boost converters. In one embodiment, a precharge method for a DC-DC boost converter having a current mirror circuit that includes a reference transistor and a power transistor, can include: (i) maintaining a reference current flowing through the reference transistor as substantially constant; (ii) maintaining a drain-source voltage of the reference transistor and a drain-source voltage of the power transistor as substantially equal; and (iii) obtaining a substantially constant mirror current by reflecting the reference current through the power transistor to operate as a precharging current of a precharge circuit.

Abstract: A two-wire transmitter starter circuit is configured to stably supply power at the time of start-up. The two-wire transmitter starter circuit includes a starter current generation circuit. The starter current generation circuit is connected in parallel with a current conversion unit configured to convert a detection signal of a sensor to a predetermined DC current. The starter current generation circuit includes a first series circuit where a first resistor and a shunt regulator are connected in series, and a second series circuit where a switching element and a second resistor are connected in series. The shunt regulator includes a first control terminal connected to a connection point of the switching element and the second resistor. The switching element includes a second control terminal connected to a connection point of the first resistor and the shunt regulator.

Abstract: A total harmonic current distortion (THDi) control circuit includes a power factor correction circuit and a control circuit. The power factor correction circuit includes a boost unit, an inverter unit, and a feedback unit. The boost unit includes a switch element and a current detection element series-coupled to the switch element. The feedback unit operatively detects an output voltage and an output current of the power factor correction circuit. The control circuit calculates an output power according to the output voltage and the output current, and calculates an input voltage and an input current according to the output power. The control circuit outputs a pulse width modulation signal and controls a conduction current generated by the switch element according to the input current. The control circuit adjusts the duty cycle of the pulse width modulation signal according to the conduction current detected by the current detection element.

Abstract: The present disclosure provides techniques for power factor correction on a constant current system. In an example embodiment, the present disclosure provides a power factor correction circuit which receives a constant current power input. The power factor correction circuit provides an input voltage tuned to match the phase of the input current. The input voltage is tuned via charging and draining an input capacitor by a switching device. The switching device is driven on a duty cycle synchronously associated with the input current waveform.

Abstract: There is provided a power factor correction device including: a main switching unit including a first main switch and a second main switch performing a switching operation with predetermined phase differences; an auxiliary switching unit including a first auxiliary switch and a second auxiliary switch forming a transmission path for surplus power existing before the first main switch and the second main switch are turned on, respectively; an inductor unit positioned between a power input unit to which AC power is applied and the main switching unit and accumulating or discharging energy according to a switching operation of the main switching unit; and an auxiliary inductor unit regulating an amount of current flowing in the auxiliary switching unit in the event of a switching operation of the auxiliary switching unit.

Abstract: An apparatus and system comprise a noise cancelation power converter being configured for phase inverted synchronous operation with respect to a primary power converter. The primary power converter is operable to supply power to at least one device. The primary power converter produces a first electromagnetic interference during operation to supply the power. The first electromagnetic interference is coupleable to the device. The noise cancelation power converter further is configured with parasitic components substantially matching parasitic components of the primary power converter. The noise cancelation power converter further produces a second electromagnetic interference that is coupleable to the device.

Abstract: In an intermediate bus architecture power system, a voltage controller that generates control signals for controlling an intermediate bus voltage (VIB) output from a first stage DC-to-DC power converter to at least one second stage DC-to-DC power converter via the intermediate voltage bus. A receiver receives values of the current input to the first stage converter, or the current and voltage output by the first stage converter. The controller determines a first value of an efficiency measure using the received values corresponding to a first VIB, and determines a second value of the efficiency measure for a second VIB higher than the first VIB.

Abstract: In one aspect, a first charge pump has serially arranged charge pump stages. Inter-stage nodes between adjacent stages are pumped by a second charge pump. In another aspect, timing of the charge pump stages is controlled by at a command clock signal. The command clock signal and command data are communicated between a integrated circuit with the charge pump and an external circuit.

Abstract: A DC-DC converter receives input power from a power source and generates a regulated DC voltage as an output. The DC-DC converter contains multiple blocks, each of which is powered by a power supply received on a supply terminal. The DC-DC converter also contains a voltage regulator to generate a lower voltage from the power source. The lower voltage generated by the regulator is provided as the power supply on the supply terminal when the regulated DC voltage is less than a reference value, and the regulated DC voltage itself is provided as the power supply on the supply terminal otherwise. The regulator is switched off when the blocks are powered by the regulated DC voltage, thereby leading to increased efficiency of the DC-DC converter.

Abstract: A DC-to-DC, converter that can reduce a loss of the converter is provided. The DC-to-DC converter includes an inductor, a switching transistor connected to the inductor, and a controller that drives the transistor. The controller acquires a next step reference value for the DC-to-DC converter in a sampling time Ta. The next step reference value is expressed by an output voltage of the DC-to-DC converter or a flux linkage of the inductor. The controller determines interpolating points between a current state value that corresponds to the current reference value and the next step reference value in a sampling time Ts that is shorter than the sampling time Ta based on a loss of the DC-to-DC converter while changing from the current state value to the next step reference value. The controller supplies to the switching transistor the PWM signals with a duty that corresponds to each of the interpolating points.

Abstract: A controller may be configured to generate a control signal to activate and deactivate a switch of a switching power converter in order to control a switching period and a peak current of the switching power converter to maintain a regulated current of the switching power converter at a desired current level such that: if the switching period decreases below a minimum switching period, the controller increases the switching period by a ringing period of a voltage of the switch and increases the peak current to compensate for the increase of the switching period in order to maintain the regulated current, and if the peak current increases above a maximum peak current, the controller decreases the switching period by a ringing period of the voltage of the switch and decreases the peak current to compensate for the decrease of the switching period in order to maintain the regulated current.

Abstract: A power supply control apparatus includes a first adder configured to generate a difference signal based on a target value and a feedback signal; a compensator having a first transfer function Wc(z) and configured to generate a control signal based on the difference signal; a control target having a second transfer function Wp(z) and configured to output an output signal generated in response to the control signal; a disturbance canceller having a third transfer function {l+Wc(z)·Wp(z)}/{Wc(z)·Wp(z)} and configured to generate a disturbance cancelling signal based on the output signal corresponding to a control amount y; a second adder configured to generate a differential disturbance signal based on an output of the first adder and the disturbance cancelling signal; and a filter circuit which generates the feedback signal based on the differential disturbance signal.

Abstract: A switch mode power supply has a first and second branch of an inductive element; a first switching element and a second switching element connected in series. Both branches are coupled to a power source in parallel. A controller controls said switching elements for operating said switch mode power supply in a plurality of consecutive time periods, wherein more than two of said switching elements are closed, i.e. at least one in each branch. The power supply has a polarity switching element coupled between said branches for receiving a pulsed voltage for providing an output voltage of a switchable polarity. The controller receives a feedback signal corresponding to the output voltage, compares the feedback signal to a reference waveform, and controls said switching elements and the polarity switching element in dependence of said comparing for generating the output voltage according to the reference waveform.

Abstract: The present disclosure relates to a flexible direct current (DC)-DC converter, which includes a charge pump buck power supply and a buck power supply. The charge pump buck power supply and the buck power supply are voltage compatible with one another at respective output inductance nodes to provide flexibility. In one embodiment of the DC-DC converter, capacitances at the output inductance nodes are at least partially isolated from one another by using at least an isolating inductive element between the output inductance nodes to increase efficiency. In an alternate embodiment of the DC-DC converter, the output inductance nodes are coupled to one another, such that the charge pump buck power supply and the buck power supply share a first inductive element, thereby eliminating the isolating inductive element, which reduces size and cost but may also reduce efficiency.

Abstract: A power system for providing an output current at a regulated system output voltage includes a first power stage and a second power stage, each being a constant on-time (COT) controlled power converter. The first and second power stages generate respective first and second regulated output voltage having reduced or very small output ripple at a common output voltage node. The first and second power stages each includes a ripple injection circuit to inject a ripple signal to the feedback control circuit in each power stage. The power system further includes a current sharing control circuit configured to measure a first output current of the first power stage and a second output current of the second power stage, and to generate a control signal to modulate the feedback control circuit of the second power stage to force the second output current to equal to the first output current.

Abstract: An AC to DC converter system is disclosed in which a conversion circuit for converting an AC input signal to a DC output signal is operably coupled with an enabling circuit designed for sensing and output parameter indicative of the presence or absence of a load at the DC output. The system is designed so that the conversion circuit operates in an inactive standby state when there is no load, and in an active state for supplying DC power when a load is present. The enabling circuit is configured to operate using low power.

Abstract: A power supply device is provided. The power supply device includes: a transformer configured to include first and second windings; a half bridge circuit configured to be connected to first and second nodes and both ends of the first wiring; and a full bridge circuit configured to be connected to third and fourth nodes and both ends of the second winding. Since the leakage inductance of the transformer and the bridge capacitor of the half bridge circuit form a direct current (DC) resonant tank, switching loss that may occur during the turning on or off of switches can be reduced.

Abstract: A converter transformer (7) with a primary winding and a secondary winding, an integrated current transformer arranged to measure a winding current of the converter transformer, and a synchronous rectifier (11, 12) connected to the secondary winding of the converter transformer are provided. A controller is arranged to close respectively to open the synchronous rectifier depending on the measured winding current. The controller is arranged to close and/or to open the synchronous rectifier as a function of the winding current at a later and/or at an earlier time, whereby the time difference between the later and the earlier time is linearly dependent on the winding current difference, particularly to optimize a discharge process, and/or that an auxiliary supply circuit is arranged to provide auxiliary supply power, wherein the auxiliary supply circuit is arranged to derive auxiliary supply power from the integrated current transformer, in particular in overload situations.

Abstract: Provided is a synchronous rectifier circuit which, even if a synchronous rectification element having a low on-resistance is used, can perform a synchronous rectifying operation without being influenced by the inductance component. It is a synchronous rectifier circuit having a synchronous rectification element QSR1 and a synchronous rectification control circuit IC1 for turning on/off the synchronous rectification element QSR1 in accordance with the current iSR flowing through the synchronous rectification element QSR1, including a current detection circuit for detecting the current iSR flowing through the synchronous rectification element QSR1 during an on-period of the synchronous rectification element QSR1 as a synchronized voltage waveform, the synchronous rectification control circuit IC1 being configured so as to turn off the synchronous rectification element QSR1 on the basis of the voltage waveform detected by the current detection circuit 1a.

Abstract: A power conversion device includes: a plurality of cascade-connection type single-phase power converters; and a central control unit that controls the plurality of the single-phase power converters, wherein each of the plurality of single-phase power converters has a single-phase power converter control unit, and the central control unit and the plurality of the single-phase power converter control units are connected via a communication means having a daisy-chain configuration, wherein the single-phase power converter control unit transmits and receives a control signal via the communication means having the daisy-chain configuration, as well as a specific pattern signal, other than a control signal frame, which can be distinguished from the control signal frame, and determines a communication error due to not receiving the specific pattern signal at the single-phase power converter control unit, or an inconsistency between the received signal and the specific pattern signal.

Abstract: The invention relates to a method for actuating the switching transistors of a rectifier which is provided for converting the phase voltages that are provided by a vehicle generator into a direct current voltage. Each switching transistor comprises a parasitic diode. An activation signal for initiating the conducting phase and a de-activation signal for ending the conducting phase are supplied to each control terminal of the switching transistors. A timer is started simultaneously with the provision of an activation signal and the de-activation signal is provided once a predetermined time period has passed.

Abstract: A method for operating an electrical power rectifier. The power rectifier comprises at least two branches that are connected in parallel to each other, each of the branches comprising at least two power semiconductor elements that are connected in series. The collector-emitter voltage Vce(t) and/or the collector current Ic(t) of one of the power semiconductor elements is detected by means of the method. Furthermore, it is determined whether at least one of the following conditions is met: dVce(t)/dt<(dVce/dt)crit, and/or dIc(t)/dt<(dIc/dt)crit, and or Ic(t_ent)<Iccrit. If at least one of the aforementioned conditions has been met, the gate-emitter voltage of at least one of the power semiconductor elements is increased.

Abstract: Systems and methods are provided for controlling an uninterruptible power supply (UPS) to transition between three- or higher-level operation and two-level operation in a neutral-point-clamped (NPC) inverter. In an example, a UPS system includes an NPC inverter and a controller. The NPC inverter may supply power to a load. The controller may control the inverter to operate in a three-level mode or higher when the load is substantially balanced and to operate in a two-level mode when the load is substantially unbalanced.

Abstract: The present disclosure proposes an input power of each unit power cell of a cascaded H-bridge inverter that is mutually insulated. To this end, the present disclosure includes a phase shift transformer configured to output a voltage of predetermined phase by receiving an AC input power having a fixed frequency, and a plurality of unit power cells serially-connected configured to output a voltage having a predetermined phase by receiving a voltage provided by the phase shift transformer, wherein the phase shift transformer is configured to include the number of phase shifts corresponding to the number of the plurality of unit power cells.

Abstract: This invention belongs into the field of power electronics and semiconductor converter control and pertains to the method of shoot-through generation for modified sine wave Z-source, quasi-Z-source and trans-Z-source inverters. The inverter can be controlled using either the modified sine wave pulse-width modulation or phase-shift modulation method. There are three methods for shoot-through generation in the case of modified sine wave control: by overlapping active states, during the freewheeling state and during the zero state. To equalize switching losses in the case of unsymmetrical switching patterns, control signals of upper and lower switching elements are periodically interchanged.

Abstract: Aspects of the invention are directed to a gate driving circuit for a power conversion circuit having an upper and lower arm circuit composed of series-connected upper arm and a lower arm, each arm including two or more semiconductor switching devices connected in series. In some aspects, a gate driving circuit of the invention includes a circuit of series connection including a diode and a resistor between a positive potential side of a positive side power supply and a positive electrode side. The gate driving circuit can determine a short-circuit fault of the semiconductor switching device that is connected to the gate driving circuit by detecting the current that flows through the circuit of series connection including the diode and the resistor when an OFF command of ON/OFF command signals is given to the semiconductor switching device.

Abstract: A multilevel power converter circuit driven by two direct current power supplies in series includes a first semiconductor switch series circuit that combines a series circuit of 2n IGBTs connected between positive and negative electrodes with a capacitor, a second semiconductor switch series circuit that combines a series circuit of 2n?2 IGBTs connected between the emitter of a first IGBT of the first semiconductor switch series circuit and the collector of a 2nth IGBT with a capacitor, and a bidirectional switch connected between an intermediate point of the second semiconductor switch series circuit and an intermediate point of the direct current power supply, to reduce a voltage change in the alternating current output when semiconductor switches are switching.

Abstract: A soft start device for a power cutting machine tool, a control circuit group includes two end, one of which is connected with an input power source and the other is connected with each of two control switches. When the input power source provides a working voltage for the control circuit group, the control circuit group outputs a low-level signal to the control switches to enable a light emitting circuit group to lighting gradually from dark to light, whereby a resistance of a trigger circuit group decreases gradually to make motor setup the working voltage. Next, the control circuit group outputs a high-level signal after a period of time, to turn on the control switches for inputting voltage to the motor directly. The soft start device can not only decrease the noise during activation of the motor but effectively protect the internal components of an electronic device from damage.

Abstract: The present invention provides an auxiliary excitation winding set to be installed at the rotary part of the electric machine (104) composed of a rotary part of the permanent magnetic electric machine or a rotary part of the reluctance electric machine of the switched DC electric machine with conduction ring and brush (1000), and an electric conductive annular brush device (107) is served as an interface for transmitting the electric power, thereby inputting the excitation electric power to the auxiliary excitation winding set; and through controlling the value and the polarity of excitation voltage and current, the magnetic pole of the rotary part of magnet-motive electric machine (104) of the switched DC electric machine with conduction ring and brush (1000) can be performed with the excitation effect of auxiliary excitation or differential excitation or auxiliary compound excitation or differential compound excitation.

Abstract: A DC link is provided, which includes a capacitor connected in parallel to an output of a converter circuit, and outputs a pulsating DC link voltage. An inverter circuit is provided, which converts an output of the DC link to AC by switching, and supplies the AC to a motor connected thereto. A controller is provided, which controls switching of the inverter circuit so that motor currents pulsate in synchronization with pulsation of a power-supply voltage. The controller controls the switching of the inverter circuit in accordance with a load of the motor or an operational state of the motor, and reduces pulsation amplitude of the motor currents.

Abstract: Determining the rotor angle of a synchronous machine. In one aspect, the invention provides a method that includes generating a multiplicity of pulse-width-modulated drive signals for the phases of an inverter feeding the synchronous machine depending on a voltage to be fed into the synchronous machine, and applying a first phase shift to one or more of the multiplicity of pulse-width-modulated drive signals, so that the duration of the switching states of the inverter is extended in order to generate a first switching pattern for the phases of the inverter. The method also includes applying a second phase shift to one or more of the multiplicity of pulse-width-modulated drive signals for generating a second switching pattern, selecting one or more of the first and second switching patterns, determining one or more of neutral point potentials at the neutral point of the synchronous machine, and calculating the rotor angle of the synchronous machine.

Abstract: The subject matter described herein includes an active compensatory augmented diode bridge rectifier system. According to one aspect, the system includes a generator unit configured to generate a current flow made up entirely of active current and a diode rectifier configured to receive the active current from the generator unit, to direct the active current to a connected power grid, and to receive a reactive current. The system further includes an active compensator configured to optimize the generator unit to produce the active current and to generate the reactive power used to facilitate the operation of the diode rectifier.

Abstract: A motor driving device of the present invention is a motor driving device that incorporates so-called vector control of controlling a current applied to a motor winding in accordance with the position of a rotor. The motor driving device receives the input of a duty command value from a host controller via a command input port, for example. The motor driving device obtains a current command or a speed command as a command value such that the input duty command value is equal to the duty of a drive pulse output from an inverter. Then, the motor driving device performs vector control based on the obtained command value.

Abstract: An electric motor system having substantially independent hardware-based and software-based pathways for detecting and initiating responses to fault conditions, such as over-current conditions, in an electric motor which is powered by a power inverter which is controlled by a power module and a microprocessor. Each pathway involves comparing a voltage, which is representative of an electric current flowing to the motor, to a predetermined maximum voltage, and if the former exceeds the latter using hardware or software to initiate shutting off the motor, such as by shutting off the power inverter. When one pathway detects a fault condition it may notify the other pathway, and the notified pathway may also initiate shutting off the motor.

Abstract: An ECU having two inverters outputs AC currents, which have the same amplitude and a phase difference of 30°. When motor magnetic fluxes include distortion component of fifth harmonic, a torque ripple of sixth harmonic is generated in a torque of each drive system. The torque ripples of sixth harmonic are cancelled out in a sum of torques of the two drive systems. A fifth harmonic current having a frequency of fivefold are superimposed on base components of currents so that peak values of the base wave currents are reduced. As a result, heat generation arising from current peak values can be reduced.

Abstract: An apparatus and a method for driving a voice coil motor (VCM) may include an instruction signal generating unit generating an instruction signal according to a digital signal generated from an input signal, and a driving unit driving the VCM by selecting a path for a driving current applied to the VCM according to the digital signal and controlling a duty of the driving current according to the instruction signal.

Abstract: A pre-charging system for a capacitor in a voltage inverter for an electric motor is provided. The system includes a microprocessor that generates a first control signal, and a pre-charging circuit coupled to the microprocessor. The pre-charging circuit has a counter circuit, a voltage pulse generating circuit, and a drive circuit. The counter circuit generates a first plurality of voltage pulses, in response to the first control signal. The voltage pulse generating circuit generates each voltage pulse of a second plurality of voltage pulses at a respective time interval while an instantaneous current flowing through a pre-charging resistor is less than a threshold level. The drive circuit has a transistor that outputs a third plurality of voltage pulses in response to the second plurality of voltage pulses to increase a voltage across the capacitor.

Abstract: There is provided a motor drive control apparatus that includes a resistor, which directly or indirectly detects a driving current supplied to a motor and generates a voltage corresponding to the driving current, converts, with an AD converter, the voltage corresponding to the motor driving current detected by the resistor into a numerical value, and reflects the motor driving current converted into the numerical value on driving control for the motor, wherein a plurality of the resistors is connected in series to form a resistor string, and voltage between arbitrary two points of the resistor string is AD-converted.