Abstract: A bi-power motor controlling apparatus, which is electrically connected with a motor, includes a driver IC having a first pin and a second pin. The first and second pins are used to receive a first power and a second power, respectively, from outside. The second power is supplied to the driver IC, and the first power is supplied to the motor for controlling the rotational speed of the motor.

Abstract: A control device for performing PWM control of an inverter includes a synchronous PWM control circuit for generating a control command for the inverter by performing PWM control based on a comparison between a sinusoidal voltage command signal for operating the AC motor according to, an operation command and a carrier signal, and a carrier generating unit for keeping an integer as a synchronization number being a frequency ratio between the voltage command signal and the carrier signal, and producing the carrier signal by switching the synchronization number according to an operation state of the AC motor. The carrier generating unit adjusts a phase relationship between the voltage command signal and the carrier signal according to the synchronization number such that an AC current transmitted between the inverter and the AC motor according to the control command provided from the synchronous PWM control circuit is symmetrical with respect to a boundary between positive and negative portions.

Abstract: A circuit for filtering narrow pulse and compensating wide pulse, including a signal shaping circuit, a filter circuit, and a pulse width compensating circuit. The signal shaping circuit processes an input signal and transmits the input signal to the filter circuit. The filter circuit filters off narrow pulses of the input signal. The pulse width compensating circuit compensates the wide pulses of the input signal and outputs an output signal.

Abstract: A power supply apparatus of a home appliance which meets standby power regulation of 0.5 watts using one SMPS. As compared with a general circuit which meets the standby power regulation using two or more SMPSs, it may be possible to curtail expenses required for addition of a separate standby only SMPS and miniaturize a PCB, resulting in a reduction in cost. Further, in a washing machine employing a motor, a circuit is provided to bypass a back EMF generated in the motor even if AC power is not supplied to the washing machine due to occurrence of a power failure or unplugging of the washing machine. Therefore, it may be possible to prevent a PCBA from being damaged due to the back EMF.

Abstract: A control system is provided for an AC electric motor which comprises a rotor and a stator and a plurality of phase windings connected in a star formation, each winding having one end connected to a common neutral point and another end arranged to have a terminal voltage applied to it. The control system comprises switching means arranged to control the terminal voltages applied to the windings and control means arranged to control the switching means so as to switch it between a plurality of states in each of a sequence of PWM periods. The control means is further arranged to measure the voltage at the neutral point at sample times within the PWM periods and to generate from the measured voltages an estimation of the rotational position of the rotor.

Abstract: The present invention provides a synchronous motor drive system designed to realize reduced vibration and noise along with high output. The system includes: inverters 101, 102, and 103 for converting a direct current to a three-phase alternating current; a current application control unit 52 that controls operations of the three-phase inverters; and a synchronous motor 41 driven by three-phase alternating currents supplied from the three-phase inverters. The current application control unit 52 determines, for each three-phase inverter, a current phase angle and a current amount of a three-phase alternating current to output, and each inverter supplies a three-phase alternating current having the determined current phase angle and current amount to a different one of three-phase coil groups 200a to 200c.

Abstract: The invention relates to a method for operating an electric motor (2) having a phase angle control with the following steps: Applying an AC voltage to a series connection of the electric motor (2) and a switching element (4), particularly a triac, wherein the switching element (4) connects through by applying an ignition signal and suppresses the flow of a current if the amount of current falls below a holding current; determining the time of a zero crossing of a virtual motor current that would flow if the switching element (4) were connected through; and turning on the switching element (4) at an activation time that is dependant on the time of the zero crossing of the virtual motor current.

Abstract: A two-phase BLDC motor comprises a stator and a rotor. The stator has a stator core and a two-phase winding wound on the stator core. The stator core comprises a plurality of teeth with slots formed between adjacent teeth. The rotor rotor has a plurality of magnetic poles formed by at least one permanent magnet. The windings are received in corresponding slots in such a way that each winding spans multiple teeth and the direction of current flowing through the windings in any one slot at any one time is the same.

Abstract: The present invention provides an electronic commutator circuit for use with a stator winding of an electrical machine. The stator winding of the electrical machine includes a number of coils linked by the same number of points of common coupling. The electronic commutator circuit comprising the same number of switching stages, each switching stage being connected between a respective one of the points of common coupling and first and second dc terminals. Each switching stage further includes a first reverse blocking semiconductor power device (such as a Reverse Blocking Gate Turn Off Thyristor (RB-GTO 1) capable of being turned on and off by gate control having its anode connected to the first dc terminal, and a second reverse blocking semiconductor power device (RB-GTO 2) capable of being turned on and off by gate control having its cathode connected to the second dc terminal.

Abstract: Systems and methods for transmitting and/or utilizing high voltage DC (HVDC) electric current in a submarine environment. The systems and methods may include the use of a submarine hydrocarbon pipeline to transmit both the HVDC electric current and a fluid stream. The systems and methods also may include the use of the HVDC electric current to do mechanical work within the submarine environment. Additionally or alternatively, the systems and methods may use a pressure-compensated electronics apparatus (PCEA) to receive the HVDC electric current and to produce a conditioned electric current therefrom.

Abstract: A head of a hard disc device is retracted to a predetermined position by operating a VCM (Voice Coil Motor) driver. Trouble in a hard disc is detected and retraction is performed even if a short circuit occurs in either of the output line of a VCM driver in an input end of a high potential side or in an input end of a low potential side. A ground short circuit is detected in each side separately and different retracting methods are executed for each case.

Abstract: A motor drive circuit configured to supply drive currents to drive coils with a plurality of phases of a motor to drive the motor, includes: a trapezoidal wave signal generation circuit configured to output a trapezoidal wave signal whose inclination is changed with a rotation speed of the motor or a target rotation speed of the motor; and a plurality of output transistors configured to output the drive current to the drive coils, respectively, in accordance with the trapezoidal wave signal.

Abstract: A method for adjusting rotational speed of a motor is also disclosed. The method includes determining whether an input voltage of the motor enters into a predetermined voltage range; generating a pulse width modulation signal when the input voltage of the motor enters into the predetermined voltage range; and driving the motor to rotate according to the pulse width modulation signal.

Abstract: A drive system for an electrical load such as an electric motor or generator comprises a PWM converter and a controller therefore. A signal indicative of a condition of the converter outpost is used in a controller to drive an optimal value of PWM switching frequency based on a load characteristic that is used to control the pulse switching frequency. The system takes account of the overall system in deriving an efficient PWM switching frequency.

Abstract: In the case where DC power from a DC power supply is converted to AC power by an inverter and supplied to an AC motor, a power compensator is connected in parallel with a DC power input portion of the inverter, and a control device of the power compensator charges/discharges a power storage device to perform a power compensation process A when power demand for the AC motor exceeds a predetermined value, and takes into account power allowance which can be inputted and outputted from the DC power supply to the power storage device and performs a power storage adjustment process B of performing auxiliary charge of the power storage device within the range of the power allowance when the power compensation process A is unnecessary.

Abstract: An excavator drive system wherein one of a pair of propulsion motors shares one of a pair of inverter power sources with another of a pair of motors dedicated to crowd and hoist motions. A pair of non-volatile bi-state switches, triggered under control of a controller, allow sharing of inverters between hoist and propel 1 motors. Another pair of switches allows inverter sharing between propel 2 and crowd motors. Each pair of switches enables change over and power transfer from one of the paired motors to the other motor. The bi-state switches enable quicker transfer of power between motors than transfer switches employing external motor-powered mechanical transfer linkages. Bi-state transfer switches also maintain transfer coupling status in the event of power failure to the switch actuators, allowing an excavator operator to continue the drive function in operation prior to the switch power failure.

Abstract: Disclosed is an apparatus and method for controlling switching devices for a DC motor, which controls the dead-time in an on-chip manner, even when a microcontroller is not mounted in a vehicle controller, by providing a semiconductor chip for controlling switching devices for a DC motor. More specifically, switching devices are mounted in a semiconductor chip to configure an internal circuit of the chip with a half-bridge and a dead-time controller is provided on the semiconductor chip and is configured to transmit gating signals by controlling dead-time periods during operation of the switching devices and drive the switching devices directly connected to a motor.

Abstract: An electrical full bridge circuit configuration having a bridge circuit, in the bridge branches of which electrical switch elements are situated, and having at least one bridge cross branch for connecting an electric motor that is switchable in its direction of rotation, in particular in an electrical system of a motor vehicle, and having a protective switch element for protecting against inadmissibly high electrical currents, in particular short circuit currents. For this purpose, the switch elements are provided as formed from switch contact elements of at least one relay.

Abstract: An actuator system having an actuator with an auxiliary switch. Make and break connection positions of the auxiliary switch relative to a rotative position of an output shaft coupling may be adjusted electronically according to an adjustment signal. The adjustment signal may be conveyed to the actuator from a computer or controller via a two-wire polarity insensitive bus. The adjustment signal may instead be provided an auxiliary potentiometer.

Abstract: An electric system that includes a single-phase permanent-magnet electric machine and a control system for driving the electric machine under load at speeds in excess of 60 krpm. Additionally, a product that includes the electric system.

Abstract: A drive with heat dissipation and energy-saving function for supplying power to drive a motor. The drive includes a driving circuit having a rectification section. The rectification section serves to receive AC current generated when the motor abruptly accelerates/decelerates and convert the AC current into DC current and output the DC current. The drive further includes a cooling module electrically connected to an output end of the rectification section. The cooling module is drivable by the DC current output from the rectification section to conduct out and dissipate heat.

Abstract: A permanent magnet generator system provides protection from fault conditions. The system includes a permanent magnet generator having a first, second, and third winding wherein each winding has a first end and a second end. During the normal mode of operation, the first ends of the windings are shorted to a first neutral point and alternating current (AC) voltage developed in the first, second and third windings is provided to a primary output associated with the second ends of the windings. In response to a fault condition on the primary output side of the system, the second ends of the windings are shorted together to a second neutral point and the first ends of the windings are disconnected from the first neutral point. During the backup mode, AC voltage developed in the windings is provided to a secondary output associated with the first ends of the windings.

Abstract: The invention relates to converters (inverters, pulse or frequency converters) and to driving “magnetically active” operating means. According to one embodiment, a circuit arrangement for feeding the operating means in at least one first winding phase (S1), comprises a first branch (Z1) of a frequency converter (WR1) adapted for and operable at a switching frequency of not higher than 5 kHz for outputting a main alternating current generated at said switching frequency and having a substantially lower operating frequency (f1) to a winding (L1). A second branch (z1) of another frequency converter (WR2) is adapted for and operable at a second switching frequency of more than 5 kHz for outputting a supplementary alternating current generated at said switching frequency to the same winding (L1). In the at least one winding (L1), the two alternating currents (iA(t); iB(t)) of the two branches (Z1, z1) are superimposed to form a sum current.

Abstract: The present invention discloses a controllable rectification comprising an inverter (10), a control panel (20) and a drive panel (30). The inverter (10) may comprise three switch element groups connected in parallel. Each switch element group may comprise at least two switch elements connected in parallel. Each switch element may comprise an upper bridge-arm switch and a lower bridge-arm. The control panel (20) may generate a PWM waveform. The drive panel (30) may generate a drive voltage according to the PWM waveform to drive the upper bridge-arm switch and the lower bridge-arm switch of each switch element to conduct or break respectively, and to make the upper bridge-arms of the same switch element group to conduct or break simultaneously, and to make the lower bridge-arms of the same switch element group to conduct or break simultaneously. The present invention further discloses an electric motor comprising the same.

Abstract: A motor drive controller includes a position detector that detects and outputs positional signals representing rotational positions of the magnetic rotor at first resolution, a position change detector that detects and outputs position change signals representing rotational positions of the magnetic rotor at second resolution higher than the first resolution, a phase synchronizing circuit that generates and outputs low resolution absolute phase information based on the positional and position change signals. The phase synchronizing circuit generates and outputs high-resolution absolute phase information based on the position change signals. A drive voltage signal outputting device outputs a drive voltage signal causing the current to flow through the coils in accordance with the absolute phase information.

Abstract: An active pull-up system for use with a motor is described. The active pull-up system comprises: a first resistor coupled to an output node; a first switch and a second resistor coupled in parallel with the first resistor, wherein the first switch is in series with the second resistor; a latch coupled to the first switch for either keeping the first switch open or closing the first switch in response to receiving a closing signal; and a threshold comparator coupled between the output node and the latch, wherein the threshold comparator transmits the closing signal when the output node exceeds a threshold value, which actively pulls up the output node.

Abstract: A motor driving circuit is applied to a motor unit, a pushrod unit, and a load unit. The motor unit is driven by the motor driving circuit. The pushrod unit is driven by the motor unit to lengthen or shorten. The load unit is pushed by the pushrod unit. A relay unit of the motor driving circuit is provided to brake the motor unit, thus raising the self-locking force of the motor unit when the pushrod unit lengthens to the maximum length or shortens to the minimum length, or the power supply is cut off.

Abstract: Proposed is a parallel inverter drive system including includes a plurality of inverter drives connected in parallel with each other, in which each inverter drive includes a switch; a PWM controller connected to the switch for controlling switching operations of the switch device according to a duty cycle signal; and a circulating current suppressor for collecting current information associated with the current of each inverter drive and a summation current, and generating an index according to the collected current information and the desired circulating current quantity. A zero-sequence voltage is generated for each phase of a three-phase voltage command according to the index and the voltage command and the operating mode of the inverter drive, thereby injecting the zero-sequence voltage into the voltage command with a feed-forward configuration so as to fix the voltage command. The PWM controller can generate the duty cycle signal according to the fixed voltage command.

Abstract: A drive device for an adjusting device for adjusting a vehicle component of a vehicle includes an electronically commutated motor and an electronic control device which actuates the electronically commutated motor with an actuating voltage. The electronic control device can adapt the signal form of the actuating voltage on the basis of at least one operating parameter in order to optimize the power output, the acoustics, the electromagnetic irradiation and/or the heating of the drive device.

Abstract: A multiphase motor driving device has an inverter circuit. The inverter circuit includes a pair of upper and lower switching elements, a shunt resistor for phase current detection, and a voltage for driving a multiphase motor. The device includes a determination unit for shifting a detection timing of the current flowing to the shunt resistor from the OFF period to the ON period of the switching element on the upper side in the phase. The determination unit determines whether or not ON failure occurs based on the current flowing to the shunt resistor of the phase in the ON period. The device has a current value estimation unit for estimating a current value of the phase in a case where the detection timing is shifted based on currents flowing to the shunt resistors of other phases.

Abstract: The control apparatus controls a controlled variable of the electric rotating machine by manipulating an output voltage of a power converter circuit including switching elements operated at a set modulation index to connect positive and negative terminals of a DC power source to corresponding terminals of the electric rotating machine. The control apparatus includes a prediction section configured to predict the controlled variable for each of a plurality of cases where the power converter circuit is set in a corresponding one of a plurality of predetermined operating states, a manipulation section configured to determine one of the predetermined operating states depending on a result of evaluation by an evaluation function, and set the converter circuit to the determined operating state, and a feedback control section configured to feedback-control the output voltage of the power converter circuit at a target value by manipulating the input parameters of the evaluation function.

Abstract: For the present invention, under various running speeds statuses, the voltage supplied to the DC brushless motor is relatively increased or decreased on the basis of the internal setting of the motor drive control device with the increased or decreased load current, to prevent the shortcoming of too much change of the input impedance caused by the inductive reactance of the winding accordingly changed when the speed of the DC brushless motor is changed with the change of the load, specifically, to prevent the shortcoming of unable to produce required torque resulting from the increased inductive reactance of the winding caused by increasing the rotational speed which makes the current value become too low when input by the original working voltage.

Abstract: The present disclosure includes electrical motor/generator drive systems and methods that significantly reduce inverter direct-current (DC) bus ripple currents and thus the volume and cost of a capacitor. The drive methodology is based on a segmented drive system that does not add switches or passive components but involves reconfiguring inverter switches and motor stator winding connections in a way that allows the formation of multiple, independent drive units and the use of simple alternated switching and optimized Pulse Width Modulation (PWM) schemes to eliminate or significantly reduce the capacitor ripple current.

Abstract: Disclosed include switching-mode power supplies and control methods thereof. A disclosed switching-mode power supply is coupled to an input power node and a ground node, comprising a controller, a first inductor, and a bootstrap circuit. The controller is for controlling a power switch coupled to the input power node and a connection node. The controller is powered by the connection node and an operation power node. The first inductor is coupled between the connection node and a discharge node. The bootstrap circuit is coupled between the discharge node, the operation power node and the connection node, to make an operation voltage at the operation power node substantially not less than a discharge voltage at the discharge node. The discharge node is coupled to power an output load.

Abstract: A DC motor is provided. The DC motor prevents rush or overload of current in the DC motor during and/or after power input irregularities to the DC motor. A control circuit of the DC motor is configured to control current provided to the DC motor. When power irregularities in the power input to the DC motor are detected by the control circuit, the control circuit stops generating PWM (Pulse Width Modulated) signals and stops the current provided to the DC motor. After the stoppage of PWM signals, the control circuit can perform a soft-start of the PWM signals when the power irregularities are no longer detected. The soft starting of the PWM signals generates gradual increase in current to the DC motor, thus, preventing sudden rush of current that cause malfunction of the DC motor.

Abstract: A motor-driving circuit includes: a plurality of output transistors; a first-comparator circuit to compare a voltage of each phase of driving coils of a plurality of phases in a motor, with a neutral-point voltage; a position-detecting circuit to detect a rotor position of the motor based on a comparison result of the first-comparator circuit; a switching-control circuit to supply switching signals to the plurality of output transistors according to the rotor position; and a current-limiting circuit to limit the driving currents to a first-current value so that the motor rotates at a target-rotation speed when the current-limiting circuit determines that the motor is rotating at a speed higher than or equal to a predetermined-reference-rotation speed, and limit the driving currents to a second-current value smaller than the first-current value when the current-limiting circuit determines that the motor is not rotating at the speed higher than or equal to the predetermined-reference-rotation speed.

Abstract: The present invention has an object to provide an on-vehicle air conditioner that can prevent breakage or the like caused by applying a high voltage. In an inverter system 20 that controls an operation of a motor 30 of a compressor for the on-vehicle air conditioner, a motor control microcomputer 24 operates by converting a voltage supplied from an on-vehicle battery power source 50 into a low voltage. Thus, the motor control microcomputer 24 is operated to perform failure diagnosis of a high voltage circuit Cb without a high voltage power source 40 being turned on. The failure diagnosis can be performed without power being supplied from the high voltage power source 40 to the high voltage circuit Cb, thereby preventing the high voltage circuit Cb from being broken by applying the high voltage even when there is some failure in the high voltage circuit Cb.

Abstract: A blower motor assembly having a variable speed motor that is suitable for direct, drop-in replacement in a residential HVAC (heating, ventilation, and air conditioning) system that employs a PSC motor. The blower motor assembly includes at least a neutral input and two hot AC line connections, one for connection to the heating power source and the other to the cooling power source. A sensing circuit senses which of the inputs is energized by sensing either voltage or current on the inputs. The sensing circuit delivers a corresponding signal to a motor controller to control the speed of the variable speed motor. The blower motor assembly may also be equipped with additional hot AC inputs, more than one neutral line, and several sensing circuits for sensing current or voltage in the hot inputs and/or the neutral lines for controlling various aspects of the variable speed motor.

Abstract: A movable partition system includes a movable partition including coupled panels and a lead post engaged with and movable along a track. A motor control system includes a motor coupled to the movable partition and a switching circuit coupled to the motor and for selectively coupling the motor to a positive power source and a negative power source responsive to one or more PWM signals. An encoder is configured for generating one or more rotation signals indicative of operational direction and operational speed of the motor. A motor controller is coupled to the switching circuit and is configured for improving airflow around the panels of the movable partition when the lead post of the movable partition is between a predefined position and a fully retracted position indicative of a billowing effect for the panels by adjusting pulse widths of the PWM signals to control rotational speed of the motor.

Abstract: A polyphase electrical machine controlled by at least two parallel inverters, each including a number of branches equal to a number of phases of the machine and controlled by PWM. When detecting an inverter branch is faulty, the faulty branch is isolated and the phase in question is powered by each corresponding other inverter branch. The PWM is modified to make power switches of each other branch conductive in succession, without switching while absolute value of the current of the phase in question is greater than or equal to a threshold of 80% to 120% of (n?1)Imax/n, n is number of inverters and Imax is maximum magnitude of the phase current. It is thus possible to continue generating substantially sinusoidal voltages on each of the phases, while avoiding overdimensioning the power switches to ensure in event of a fault they can deliver currents of amplitude higher than in normal operation.

Abstract: An electric drive device (1) comprises a motor converter circuit (3) according to the invention, which includes an intermediate circuit capacitor (16). The intermediate circuit capacitor (16) comprises a parallel circuit of several ceramic capacitors (24). The ceramic capacitors (24) have a lower dissipative resistance and enable better heat removal, so that the motor converter circuit (3) has a comparatively longer service life.

Abstract: A switching system includes a plurality of diodes forming a diode bridge, and a micro-mechanical system (MEMS) switch array closely coupled to the plurality of diodes. The MEMS switch array is electrically connected in an (M×N) array. The (M×N) array includes a first MEMS switch leg electrically connected in parallel with a second MEMS switch leg. The first MEMS switch leg includes a first plurality of MEMS dies electrically connected in series, and the second MEMS switch leg includes a second plurality of MEMS dies electrically connected in series.

Abstract: This invention relates to an apparatus and method for deriving speed and position information for an electric motor. Apparatus for and a method of controlling a motor 100 are also disclosed. The apparatus for providing information relating to the operation of an electrical motor 100 comprises a sampler 50, 51 for sampling the instantaneous motor current is and a processor 160 for determining the instantaneous rate of change of the motor current and providing information about the motion or position of said motor based on said instantaneous rate of change of the motor current. In this way speed and position information can be provided, at low speeds, and without using a speed sensor.

Abstract: A motor control apparatus has an inverter circuit, which includes FETs for converting electric power supplied to a motor. A capacitor is provided between a battery and the inverter circuit. A pull-up resistor connects a V-phase of the motor to a high potential side of the battery. A power supply relay permits or interrupts current flow from the battery to the capacitor and the motor. A microcomputer controls the power supply relay and the motor. The microcomputer turns on a low-side FET of a V-phase under a condition that the power supply relay is interrupting the current flow before the motor is started. Electric charge stored in the capacitor is discharged to a low potential side of the battery through the pull-up resistor.

Abstract: Provided is an inverter-integrated motor including a motor and an inverter integrated in an efficient manner. Also provided is a semiconductor chip that can be used in this motor. An IGBT chip is constructed with an emitter terminal being provided at the apex of one face of a die having a regular triangular surface shape, a gate terminal being provided adjacent the opposite side to the apex, and a collector terminal being provided on the other face. A power semiconductor module is constructed with placing apices of the IGBT chips having the emitter terminals in abutment against each other. Six such power semiconductor chips are arranged in a regular hexagonal pattern to together constitute an inverter for converting DC power into three-phase AC power.

Abstract: This invention provides a motor drive circuit, which makes it possible to prevent braking when a power supply voltage is lower than a predetermined voltage while suppressing at a low cost a rise in a voltage on a power supply line when a kickback occurs. The motor drive circuit is formed to include first and second power supply lines connected with and shunted from a power supply, an H-bridge circuit, and a means to control the H-bridge circuit. The means controls the H-bridge circuit so that a regeneration path is not created in the H-bridge circuit when the power supply voltage is lower than a predetermined voltage.

Abstract: The invention relates to a brushless motor drive device that performs switching determination of energization modes of a three-phase brushless motor according to a sensorless method, and a drive method thereof. A pulse induced voltage induced in a non-energized phase of three phases by a pulse voltage is compared with a threshold to determine the switching timing of the energization modes. Here, by limiting a duty ratio of a voltage application to equal to or greater than a lower limit, a situation in which the pulse induced voltage is sampled while the pulse induced voltage is oscillating is avoided, and a situation in which the pulse induced voltage falls below a voltage detection resolution is avoided. As a result, determination of energization mode switching timing based on a pulse induced voltage can be performed more stably.

Abstract: An inverter system for operating an electric motor includes an input port for providing an electrical voltage, a bridge inverter circuit connected downstream from the input port for generating an electrical alternating voltage for the electric motor based on the electrical voltage. The bridge inverter circuit has at least one half-bridge branch including switching elements configured to be open for transferring the electric motor into a freewheeling state, and a decoupling switching element designed for decoupling the at least one half-bridge branch in the freewheeling state of the electric motor from the input port, in order to suppress a reaction of the freewheeling electric motor on the input port.

Abstract: The invention relates to a circuit arrangement for the selective operation of at least two electric machines (1, 2) that are each supplied via a plurality of phase lines, comprising:—one voltage protection module (5) for limiting an intermediate circuit voltage,—one switch arrangement (4) for selecting one of the electric machines by switching the phase lines;—first choke inductivities (8) in each of the plurality of phase lines between the circuit arrangement (4) and the voltage protection module (5), wherein one second choke inductivity (9?) each may be switched parallel to one or more first choke inductivities (8) as a function of the selected electric machine (1, 2), can be switched.

Abstract: A sensorless permanent magnet motor system that prevents negative torque caused by back EMF. The system determines the position of the rotating permanent magnet by monitoring back EMF generated on an inactive coil of the motor system. A snubber circuit is used to prevent the back EMF from causing negative torque on the motor. The voltage of back EMF used to power a logic circuit, such as a microcontroller, that controls the operation of the motor. The microcontroller controls the operation of the motor by detecting back EMF and is also partially powered by the back EMF.