Abstract: Disclosed are an apparatus for diagnosing a relay contact of an electric vehicle and a method thereof. The method includes measuring a first voltage input from a high-voltage battery to an inverter; comparing the first voltage with a second voltage output through the high-voltage battery; identifying a detection time point of the first voltage when the first voltage is greater than the second voltage; and determining whether a high-voltage relay, which intermits an output voltage of the high-voltage battery, is malfunctioned based on the identified detection time point.

Abstract: An electric motor control apparatus capable of controlling a motor normally regardless of failures is obtained without increased cost. The apparatus includes a position sensor failure determination unit which outputs a failure determination signal, and generates a first phase; a motor rotation speed calculator which operates based on the failure determination signal and position sensor signals; a phase command generator producing a phase command based on the first phase, the failure determination signal and rotation speed; an amplitude command generator that generates an amplitude command indicating magnitude of a driving signal for the motor, and an electrical energization unit that applies the driving signal to the motor based on the phase command and the amplitude command. Upon failure of a position sensor, the phase command generator generates the phase command using the first phase, and a second phase obtained based on the first phase and the rotation speed.

Abstract: An electronically commutated motor (ECM) often employs a Hall sensor for reliable operation. Even when a Hall sensor is omitted from a motor having a plurality of stator winding phases (24, 26) and a permanent-magnet rotor (22), one can reliably detect direction of rotation of the rotor by the steps of: (a) differentiating a voltage profile obtained by sampling either (1) induced voltage in a presently currentless phase winding or (2) voltage drop at a transistor, through which current is flowing to a presently energized phase winding, and (b) using such a differentiated signal (du—24?/dt, du—26?/dt) to control current flow in an associated phase winding. In this manner, one obtains reliable commutation, even if the motor is spatially separated from its commutation electronics.

Abstract: Embodiments of the present invention relate to methods, systems, a machine-readable medium operable in a controller, and apparatus for controlling a multi-phase inverter that drives a multi-phase electric machine. When a sensor fault is detected, a phase current angle is computed based on the feedback stator currents, and used to estimate an angular velocity and an angular position of a rotor of the multi-phase electric machine. When the estimated angular velocity of the multi-phase electric machine is less than a transition angular velocity threshold, an open-circuit response can be applied at the multi-phase inverter by controlling all switches in the multi-phase inverter drive to be open. By contrast, when the estimated angular velocity is greater than the transition angular velocity threshold, a short-circuit response can be applied at the multi-phase inverter by controlling selected switches in the multi-phase inverter drive to connect all phases of the multi-phase inverter to a single bus (e.g.

Abstract: Disclosed herein are a motor driving apparatus and method. The motor driving apparatus includes: an inverter including a main driver sequentially activating N phases and a spare driver activating a spare phase substituting for a faulted phase among the activated N phases; a detecting unit detecting the respective output signals of the N phases; a switching unit performing switching so that the spare phase is connected to the faulted phase of the exited N phases; and a controlling unit driving the inverter to determine whether or not a fault is generated and control the switching unit so that the faulted phase is connected to the spare phase. Therefore, since the motor may be driven without replacing the inverter, a cost may be reduced, and since the motor may be driven without a change in the number of phases, the motor may be efficiently and stably driven.

Abstract: An electronically commutated motor (ECM) often employs a Hall sensor for reliable operation. Even when a Hall sensor is omitted from a motor having a plurality of stator winding phases (24, 26) and a permanent-magnet rotor (22), one can reliably detect direction of rotation of the rotor by the steps of: (a) differentiating a voltage profile obtained by sampling either (1) induced voltage in a presently currentless phase winding or (2) voltage drop at a transistor, through which current is flowing to a presently energized phase winding, and (b) using such a differentiated signal (du—24?/dt, du—26?/dt) to control current flow in an associated phase winding. In this manner, one obtains reliable commutation, even if the motor is spatially separated from its commutation electronics.

Abstract: A motor drive control device is configured to control driving of a brushless DC motor including a stator having drive coils, a rotor having plural magnetic poles, and plural position detecting units that output position detection signals representing position of the rotor with respect to the stator. The motor drive control device includes a drive voltage generating unit configured to generate and output drive voltages to the motor to drive the motor. An abnormality detecting unit can be used to detect abnormality of the position detection signals. When abnormality of at least one of the position detection signals has been detected by the abnormality detecting unit, the motor drive control device can drive the motor based on at least one of the remaining position detection signals excluding the position detection signal that has been detected as abnormal.

Abstract: An integrated circuit for implementing brushless DC motor control includes a substrate, a band gap temperature sensor, and a magnetic sensor. The substrate has a temperature output pin for connection to an external device and a magnetic sensor output pin for connection to the external device. The band gap temperature sensor is formed on the substrate and is configured to sense temperature and supply a temperature signal representative of the sensed temperature to the temperature output pin. The magnetic sensor is formed on the substrate and is configured to sense magnetic field variations and supply a sensor output signal representative thereof to the magnetic sensor output pin.

Abstract: An apparatus for driving a motor of an electric vehicle is provided. The apparatus includes a capacitor supplied with power by a battery; an inverter configured to include a plurality of switching elements, convert direct current (DC) power stored in the capacitor into alternating current (AC) power in accordance with the switching of the switching elements and drive a motor with the AC power; and a capacitor protector provided between the battery and the capacitor and configured to consume initial power supplied by the battery at an early stage of the supply of power by the battery, the capacitor protector including a common resistor that consumes the DC power stored in the capacitor when the capacitor is discharged. Therefore, it is possible to guarantee the reliability of the apparatus.

Abstract: A method for measuring at least one operating variable at multiple electric motors of an automatic parking brake with the aid of a sensor system, the signals generated by the sensor system being processed by a processing device. To minimize the influence of signal interferences, the at least one operating variable is not measured or is not further processed as long as none of the electric motors is activated.

Abstract: A motor control device detecting short-circuit and disconnection faults of a power relay includes: a drive circuit of a motor; the power relay having first and second switching elements; a capacitor; a voltage detector detecting a voltage of the first switching element; a charger charging the capacitor; and a controller detects a short-circuit fault of the first and second switching elements according to the detection voltage when the first and second switching elements turn off after the charger charges the capacitor, detects a disconnection fault of the second switching element according to the detection voltage when the first switching element turns off, and the second switching element turns on and detects a disconnection fault of the first switching element according to the detected voltage when the first switching element turns on, and the second switching element turns off.

Abstract: A sensorless control apparatus may include: a speed command unit configured to output a speed command to an electric motor; a current detector unit configured to detect electric current flowing through the electric motor if a voltage being output according to the speed command is supplied to the electric motor; a rotor angle calculation unit configured to calculate a magnetic flux of a rotor of the electric motor based on the detected electric current and the voltage being output according to the speed command, and to calculate an angle of the rotor from the calculated magnetic flux; and/or an out-of-step sensing unit configured to sense an out-of-step of the rotor according to a comparison of the calculated angle of the rotor with an angle of the rotor estimated based on a sensorless control algorithm.

Abstract: A steering control apparatus includes a direct current power source, a three-phase alternating current motor, and a motor driving circuit. An emergency switching element is provided on at least two phases of a three-phase power supply line connected to the three-phase alternating current motor within the motor driving circuit, and the emergency switching element is turned off when an abnormality occurs such that the motor driving circuit is disconnected from the three-phase alternating current motor. The emergency switching element is a MOSFET, and the MOSFETs are provided in pairs in each of the two phases of the three-phase power supply line. Further, parasitic diodes of the pairs of MOSFETs are disposed in opposite orientations to each other.

Abstract: Provided are a current detection apparatus having sensor sections detecting motor currents flowing in the windings for the phases of the winding groups, a control apparatus calculating voltage instructions with respect to each winding group, based on the motor current detected by each sensor section, a voltage application apparatus applying voltage to each winding group, based on the voltage instructions, and a failure detection apparatus detecting whether or not each sensor section has failed. The control apparatus, when the failure detection apparatus has detected failure of some of the sensor sections, in accordance with the detection, calculates a voltage instruction with respect to the winding group corresponding to the failure of the sensor section, based on motor current with respect to another winding group detected by the sensor section that can normally detect current.

Abstract: Provided is an electric pump device that can continue to supply hydraulic pressure to hydraulically actuated equipment and that is also of reduced size. An electric pump device is provided with an oil pump that supplies oil to a stepless transmission device, a brushless motor that drives the oil pump, and a control device that controls the brushless motor. The control device is provided with a power supply part that supplies drive power to the brushless motor, and an out-of-synch determination part that determines whether or not the brushless motor is out of synch. The control device is provided with a drive control part that controls the power supply part so that supply of power to the brushless motor is stopped, and then controls the power supply part so that the brushless motor is started, when the out-of-synch determination part determines that the brushless motor is out of synch.

Abstract: In a motor control device that is used for, for example, an electric power steering system or another vehicle steering system equipped with a motor, a relay circuit (40) that serves as a power supply breaker is provided in a power feed line (Lp2) of a pre-driver (22) of a circuit that is a component of the motor control device. The operation of the relay circuit (40) is controlled by a relay signal (S_rly) output from a microcomputer (21).

Abstract: A power transducer failure detection device detects a failure on a power transducer, making a power transducer control device stop driving the power transducer. A first switching control device turns off a first power supply relay of a power supply source switching device and turns on a second power supply relay of the power supply source switching device. While the power transducer stops driving, a motor may rotate due to an external force to generate a regenerative voltage. The regenerative voltage is then regenerated in a battery through a route from the power transducer via the second power supply relay being turned on and a parasitic diode of the first power supply relay. This can protect elements such as switching elements and a smoothing capacitor of the power transducer against a regenerative voltage and prevent the elements from being destroyed or reducing the useful life due to overvoltage.

Abstract: A power supply system is provided. The power supply system includes a converter converting a direct input current into a polyphase alternating output current including a plurality M of phases. The converter includes two input terminals, is arranged at the input of the element and delivers the polyphase alternating current to element. The power supply system also includes a controller controlling the converter, a storage bank including at least one storage capacitor between the input terminals, a device protecting the element from over-voltages or over-currents of the polyphase alternating current, between the converter and element, including a plurality of switching arms between the respective phases of the polyphase alternating current. Each switching arm includes two thyristors connected head-to-tail and in parallel. The controller applies a negative voltage to the terminals of at least one thyristor during a period greater than a predetermined turn-off time of the thyristor.

Abstract: In a method for controlling a synchronous machine having a stator, a rotor, and magnets situated on the rotor, first a nominal value is set for the magnetic flux prevailing in the synchronous machine, and a marker is set in a control unit that indicates that no calibration has yet been carried out. It is then checked repeatedly whether the synchronous machine has been out of operation for at least a specified time duration. If this is the case, a temperature balance between the stator and the rotor is assumed, so that the temperature to be measured at the stator is equal to the rotor temperature, and thus can be used as a basis for a calibration of the magnetic flux. A marker that indicates the carrying out of a flux calibration is set in the control unit. Subsequently, normal operation can be continued.

Abstract: A driving control device of a brushless motor includes an inverter circuit having: first arm-side switching elements that are connected between respective phases of respective armature coils of the brushless motor and one terminal of a power supply; and second arm-side switching elements that are connected between respective phases of the respective armature coils and the other terminal of the power supply, and a control unit, wherein, in a short-circuit braking according to a short-circuit braking signal, the control unit outputs a signal of turning off all the first arm-side switching element and outputs a signal of controlling the at least one of the second arm-side switching elements to perform a switching operation and turning on the other second arm-side switching elements.

Abstract: Provided is a method for controlling an inverter, the method comprising calculating an optimal speed, determining a final speed as the optimal speed when a command speed is higher than a rated speed level of a motor, and determining the final speed as the command speed when the command speed is lower than or equal to the rated speed level, or higher than a predetermined optimal speed level.

Abstract: Provided is a motor control device (10) for controlling a motor (5) provided with a plurality of sets of windings, in which, when a current control unit (23) detects a short-circuit failure as a primary failure, the current control unit (23) continues the control, and, further, when the current control unit (23) detects a secondary failure, the current control unit (23) provides control of opening a power supply relay (3). Accordingly, in a case where a failure of a winding of a motor or an inverter occurs, a torque pulsation is restrained and a sufficient output torque is provided, and further, in a case where a secondary failure occurs, excessive heat generation and current consumption are prevented and the cost of the device is reduced.

Abstract: A method for operating a brushless electric motor, the windings being energized by an inverter with the aid of six switches. A detection unit for detecting defective switches, a unit for measuring voltage at the outputs of the inverter, and a microcontroller for controlling the switch and for generating a pulse width modulated voltage supply for the windings are provided. A short-circuited switch causes a torque in the electric motor opposite the actuating direction of the electric motor. The method proposes that after detecting a short-circuited switch, the windings (U. V. W) are energized to generate a motor torque that is, on the whole, positive. An actuating period of the electric motor is divided into a plurality of sectors, wherein, in accordance with the defective switch, individual sectors are deactivated for the actuation of the windings (U, V, W), while other sectors are used to actuate the windings (V, W).

Abstract: In a method for operating an at least three-phase electric machine used as a drive assembly in a motor vehicle, which is actuated via an inverter, the inverter including switching elements in the form of half bridges which are in each case electrically connected to a respective phase of the electric machine, when a first switching element of a first half bridge connected to a first phase is permanently closed/opened on account of failure, a second switching element of the first half bridge is permanently opened/closed and, in a first angular range of an electrical rotation, which is uninfluenced by the first phase, all switching elements of the additional half bridges are actuated in the usual manner.

Abstract: A system for controlling a brushless motor includes drive circuitry in communication with the brushless motor and a primary control device in communication with the drive circuitry. The system also includes a secondary control device in communication with the drive circuitry and a multiplexer for selectively providing an output of the primary control device or an output of the secondary control device to the drive circuitry, wherein the output of the primary control device is provided to the drive circuitry when the primary control device is operating normally.

Abstract: An overspeed protection subsystem is provided for a power tool having an electric motor. The overspeed protection subsystem is comprised of: a motor switch coupled in series with the motor; a motor control module interfaced with the motor switch to control switching operation of the motor switch; and an overspeed detection module that determines rotational speed of the motor and disables the power tool when the rotational speed of the motor exceeds a threshold.

Abstract: A power supply device for a variable rotation speed drive includes a free-running converter connected to a land-based power grid, and an inverter connected to the variable rotation speed drive. A direct-current cable electrically connects the DC side of the converter with the DC side of the inverter. The inverter includes a plurality of phase modules having an upper and a lower valve branches with least two series-connected, two-pole subsystems with distributed energy storage devices. The inverter is located on the seabed in immediate vicinity of the variable rotation speed drive. Signal electronics of the inverter is located on land. In this way, the distance between the power supply on land and the drive on the ocean floor can reach several hundred kilometers, with ocean depths of several kilometers.

Abstract: A motor control apparatus includes a resolver and a R/D converter in which an electrical angle of 360° is set smaller than a mechanical angle of 360° and that outputs a two-phase encoder signal corresponding to the electrical angle; a two-phase encoder counter that counts the two-phase encoder signal and outputs a digital value corresponding to the electrical angle; a multiplication factor of angle detecting portion that detects a position of the mechanical angle to which an angle indicated by a signal output from the R/D converter corresponds, based on a change in a count value; and a motor controlling portion that corrects a current command value determined based on a torque command value, according to an output of the multiplication factor of angle detecting portion.

Abstract: A technique is provided for verifying the proper selection, installation, communication and operability of components in power electronic systems, such as motor drives. A processing circuit is coupled to multiple components or subsystems that identify themselves to the processing system. An identification code is stored that is compared to a similar code built based upon the information reported by the components at the time of commissioning, operation or servicing. If the comparison indicates that all components are properly installed, and communicating and operative, operation may continue. The technique may be applied in parallel motor drives at a power layer level to allow separate and parallel verification of component and component operation in the parallel drives.

Abstract: A temperature protection device basically includes a temperature detector, a temperature estimator, an overheated determining component and an overheating protection component. The temperature detector detects a temperature of a semiconductor component. The temperature estimator estimates an estimated temperature of the semiconductor component. The overheated determining component determines whether the semiconductor component is in an overheated state based on the detected temperature and the estimated temperature by using a first estimated temperature as the estimated temperature at a time point when the detected temperature has reached a first threshold temperature and a second estimated temperature that is estimated subsequent to the time point as the estimated temperature when the detected temperature has reached the first threshold temperature.

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 automatic power-off and actuation circuit for a fan comprises a drive unit, a detection unit, a voltage-modulating unit, a comparison unit, an auto-restart unit, a regulation unit and a controlled IC, wherein the detection unit is electrically connected to the drive unit, the voltage-modulating unit is electrically connected to the detection unit, the comparison unit is electrically connected to the voltage-modulating unit, the auto-restart unit is electrically connected to the comparison unit, the regulation unit is electrically connected to the auto-restart unit and the drive unit, and the controlled IC is electrically connected to the regulation unit and the drive unit.

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-drive circuit includes a detection circuit to detect a reverse current to flow in a direction from a first sink-side transistor to a second source-side transistor or in a direction from a second sink-side transistor to a first source-side transistor, a disable circuit to disable a detection output of the detection circuit during a predetermined time period from a start of detection of the reverse current performed by the detection circuit, a first inhibit circuit to inhibit synchronous rectification according to a detection output of the detection circuit when the predetermined time period has elapsed from a start of detection of the reverse current performed by the detection circuit, and a second inhibit circuit.

Abstract: A method and a device for monitoring the startup of an electric drive, which has a polyphase machine, a pulse-controlled inverter and a control unit. The control unit is provided to compare rotational speed values that are successive in time to one another during the startup of the drive, and when recognizing a non-increase in the rotational speed of the rotor shaft, to detect a mixup of phase lines or pulse-controlled inverter lines.

Abstract: A power conversion device includes a first inverter circuit and a second inverter circuit, a capacitor, and a microcomputer. The microcomputer switches a control operation, according to the steering state of a steering wheel, between a first state where a first duty center value is shifted to be lower than an output center value and a second duty center value is shifted to be higher than the output center value, and a second state where the first duty center value is shifted to be higher than the output center value and the second duty center value is shifted to be lower than the output center value. This can reduce a difference in heat loss between FETs while reducing the ripple current of the capacitor.

Abstract: Systems and methods of detecting a failure of a permanent magnet synchronous motor system. A current of each phase coil of the motor is monitored. A value indicative of the power of the motor is compared to a threshold value indicative of power during a low power detection period. If the value indicative of the power fails to exceed the threshold value indicative of power for the entire low-power detection period, the system indicates a first error condition. The method also monitors the speed of the motor and indicates a second error condition if the speed of the motor remains below a speed threshold for an entire speed failure detection period. A third error condition is indicated if the current of at least one phase of the motor remains below a phase current threshold for an entire loss of phase detection period.

Abstract: Various methods of detecting a found rotor, a lost rotor, a locked rotor and a caught rotor after a power disruption using flux estimates are disclosed. Also disclosed are permanent magnet motor controllers and assemblies suitable for performing one or more of these methods.

Abstract: The present invention discloses a motor driving circuit for driving a motor, including an electrostatic discharge diode, having an input port and an output port coupled to a first DC power supply, a pulse width modulation source coupled to the input port of the electrostatic discharge diode to generate a pulse width modulation signal, and a driving module including a voltage detecting module comparing the pulse width modulation signal with a voltage of the output port of the electrostatic discharge diode to generate a voltage comparison result, a lock/restart module generating a shut-down signal according to the voltage comparison result, a control module generating a control signal according to the shut-down signal, and a bridge circuit switching the motor on or off by turning on or turning off an up-bridge circuit and a down-bridge circuit according to the control signal.

Abstract: A failure identification part identifies a switching element pair having off-failure, in which a FET of the switching element pair in a first inverter part is disabled to turn on. A failure-time control part controls other switching element pairs and of the first inverter part based on failure-time phase current command values calculated as a function of a rotation position and a q-axis current command value. The failure-time control part controls a second inverter part normally. A motor is persistently driven with the minimum reduction in motor torque, even when the FET fails.

Abstract: A compressor control device includes a driving circuit, for controllably supplying a coil of an electric motor of a compressor. A temperature sensor is thermally coupled to the driving circuit and provides a temperature sensing signal correlated to a temperature in the driving circuit. A control stage, coupled to the driving circuit and to the temperature sensor, selectively prevents the driving circuit from supplying the coil, in response to a minimum temperature increment being detected by the temperature sensor within a pre-determined control time window.

Abstract: An electric power steering system includes short-circuit determination means for determining whether a short-circuit between an energization failure phase and one of the two phases other than the energization failure phase has occurred while assist force is being generated using the two phases other than the energization failure phase as energization phases. When the short-circuit determination means determines that the short-circuit has occurred, generation of the assist force is stopped.

Abstract: A control system for an electric machine, the control system including a current controller and a drive controller. The current controller includes an input, an output, a comparator and a latch. The comparator sets the latch when a voltage at the input exceeds a threshold, and the latch outputs an overcurrent signal when set. The drive controller then resets the latch after a predetermined period of time.

Abstract: Embodiments of the present invention relate to methods, systems, a machine-readable medium operable in a controller, and apparatus for controlling a multi-phase inverter that drives a multi-phase electric machine. When a sensor fault is detected, a phase current angle is computed based on the feedback stator currents, and used to estimate an angular velocity and an angular position of a rotor of the multi-phase electric machine. When the estimated angular velocity of the multi-phase electric machine is less than a transition angular velocity threshold, an open-circuit response can be applied at the multi-phase inverter by controlling all switches in the multi-phase inverter drive to be open. By contrast, when the estimated angular velocity is greater than the transition angular velocity threshold, a short-circuit response can be applied at the multi-phase inverter by controlling selected switches in the multi-phase inverter drive to connect all phases of the multi-phase inverter to a single bus (e.g.

Abstract: A protection circuit 30 for a D.C. brushless motor pump in the present invention is to be installed on or connected to a driving circuit 40. The driving circuit 40 is installed on a motor 100 of the D.C. brushless motor pump. The motor consists of a rotor set and a stator set, while the protection circuit contains a micro-processing unit, a driving unit, a comparison unit and a signal source. The micro-processing unit is electrically connected with the driving unit, the comparison unit is electrically connected with the micro-processing unit while the signal source is electrically connected with the comparison unit. The signal source is a voltage signal produced by the motor itself when the rotor set is operated. The comparison unit can convert the signal source into a rotating speed value of the rotor set, and the micro-processing unit can function to supervise and control rotating speeds of the motor.

Abstract: Disclosed is a brushless-motor drive apparatus provided with: a current detecting means (6) for detecting currents flowing through armature windings (9) during periods when switching elements (5H, 5L) of a drive circuit are ON; a calculation processing means for comparing a target current value and the detected current value, and calculating voltage command values to be applied to the armature windings (9); and a PWM driving means (4) for controlling the ON/OFF of the switching elements on the basis of the voltage command values.

Abstract: When an output pattern (LLL or HHH) due to a signal with a prescribed logic level corresponding to a ground short or instantaneous interruption of an output signal line of Hall ICs 17 is supplied via the output signal lines, and if output patterns based on detection signals supplied before and after the output pattern are found to be different by comparing them, a decision is made that there is a possibility that a shift of a rotor 11 from a target position and counterrotation of the rotor 11 involved with it can occur.

Abstract: A converter for an electrical machine having a plurality of phase lines for connecting the electrical machine. For each phase line the converter has a half-bridge with a first first semiconductor switch is configured to electrically connect at least one of the phase lines intermittently to a first supply line of the converter, and a second semiconductor switch configured to electrically connect the phase line intermittently to a second supply line of the converter. The converter is configured for operation in a first energy recovery limiting mode in which at least two of the first semiconductor switches are at least intermittently on simultaneously.

Abstract: A semiconductor integrated circuit device for an electronic control unit includes a drive circuit, a prohibition circuit and a pulse monitor circuit. The drive circuit drives an in-vehicle load according to a driving signal outputted from a microcomputer. The pulse monitor circuit monitors a pulse signal outputted from the microcomputer when the microcomputer is in a normal state. The pulse monitor circuit resets the microcomputer and instructs the prohibition circuit to prohibit the drive circuit from driving the in-vehicle load when it is determined that the microcomputer is in an abnormal state. Further, the pulse monitor circuit instructs the prohibition circuit to permit the drive circuit to drive the in-vehicle load when it is determined that the microcomputer is in the normal state after resetting of the microcomputer.

Abstract: A fan system circuit module including a stable voltage input terminal for receiving a stable voltage, an operation unit electrically connected to the stable voltage input terminal and a drive chip. The operation unit includes a first resistor, a second resistor, a first capacitor and a third resistor. After powered on at the stable voltage, the operation unit generates an operation signal for the drive chip to decrease drive current value of the fan. In case that a lock of the fan takes place, the drive chip can effectively decrease the block current. The circuit module has soft-start function and provides block current protection effect so as to avoid malfunctioning of the fan system due to too great start current of the fan and avoid burnout of the fan due to high rise of temperature.