Abstract: A patient transport apparatus for transporting a patient over a floor surface is described herein. The patient transport apparatus includes an auxiliary wheel assembly including an auxiliary wheel, an auxiliary wheel drive system, and a control system for operating the auxiliary wheel drive system based on user commands. The control system includes a processor that is programmed to receive a user command to operate the auxiliary wheel drive system in a drive mode and responsively operate a motor control circuit to transmit power signals to a motor to rotate the auxiliary wheel. The processor is also programmed to receive a user command to operate the auxiliary wheel drive system in a free wheel mode and responsively operate the motor control circuit to enable the auxiliary wheel to rotate relatively freely with the auxiliary wheel in a deployed position.

Abstract: An inverter for driving a motor that has a switchable connection of windings and drives a load element having a periodically varying load torque is provided. The inverter is controlled so that an output torque of the motor follows the periodic variation of the load torque. The inverter is controlled so that a current flowing through the motor is zero during a period including a minimum torque phase at which the load torque is at or near a minimum value. The connection is switched while the current flowing through the motor is zero. It is possible to switch the connection of the windings while the motor is rotating, and avoid an increase in apparatus size.

Abstract: A method includes determining whether a multiphase electric machine is unstable. The method also includes, in response to a determination that the multiphase electric machine is unstable, setting a gate voltage of a first three terminal semiconductor switch to zero. The method also includes, in response to a determination that the multiphase electric machine is stable, setting the gate voltage of the first three terminal semiconductor switch to nonzero. The method also includes, in response to the first three terminal semiconductor switch being set to zero, increasing electrical conduction from one phase of the multiphase electric machine to another phase of the multiphase electric machine. The method includes, in response to the first three terminal semiconductor switch being set to nonzero, increasing electrical resistance from the one phase of the multiphase electric machine to the another phase of the multiphase electric machine.

Abstract: A hydraulic fracturing system includes a pump, an electrically powered motor for driving the pump, a trailer on which the pump and motor are mounted, and a transformer that steps down electricity for use by the motor. Electrical output from the transformer connects to a series of receptacles mounted onto a housing around the transformer. A similar set of receptacles is provided on the trailer and which are electrically connected to the motor. Power cables equipped with plugs on their opposing ends insert into the receptacles to close an electrical circuit between the transformer and pump.

Abstract: An open roof assembly for use in a vehicle roof of a vehicle comprises a moveably arranged closure member for selectively covering or at least partially exposing an opening in the vehicle roof, an electric motor operatively coupled to the closure member through a mechanical drive assembly for moving the closure member, an electric driving unit for providing a supply signal to the electric motor and a control unit operatively coupled to the electric driving unit for controlling operation of the electric motor. The electric driving unit comprises four switching devices in a bridged configuration and the control unit is configured to control a motion of the closure member by controlling operation of the switching devices, and to incur a safety stop during a motion of the closure member by an immediate reversal of a polarity of the supply signal.

Abstract: A control device for an on-board device including an actuator is configured to: supply power to a first microprocessor and a first driver circuit from a first power source through a first power supply path; supply power to a second microprocessor and a second driver circuit from a second power source through a second power supply path; and use the first and second driver circuits to drive the actuator. In this control device, the negative electrodes of the first and second power sources are electrically connected to a common ground portion. Furthermore, the control device includes a first and second sensor for measuring current or voltage between the vehicle body ground and the negative electrodes of the first and second power source, respectively. When detecting an abnormal current or voltage, the first and second microprocessors control the first and second driver circuits so as to place a limit on power supply to the actuator.

Abstract: A locomotive control system includes a locomotive having a traction motor and sensors. The traction motor provides tractive effort for propelling the locomotive and the sensors measure performance conditions of the locomotive. The system also includes a controller having one or more processors communicatively coupled with the traction motor. The controller selects one or more baseline conditions that designate operational conditions under which the locomotive is to operate, and monitors the performance conditions that are generated by the locomotive during operation of the locomotive according to the operational conditions designated by the one or more baseline conditions. The controller identifies a flashover condition or a plugging condition of the locomotive by comparing the performance conditions that are generated by the locomotive during operation of the locomotive with the one or more baseline conditions.

Abstract: A controller apparatus for an electric power tool is provided where the electric power tool includes a battery and a DC brushless motor. The controller apparatus includes a current detector that detects an instantaneous current flowing in the DC brushless motor; a current calculator that calculates one of an average value and an effective value of the instantaneous current detected by the current detector; a current controller configured to utilize a result from the current calculator as a detected value; and a speed controller configured to generate a target value of the current controller. The controller apparatus further includes a limiter that limits the target value of the current controller, where the limiter is provided at an output stage of the speed controller.

Abstract: To provide a motor driver and a motor driving system which allow a reduction in power consumption of a heat exchanger provided in a power magnetics cabinet while keeping down manufacturing cost. A motor driver is accommodated in a power magnetics cabinet and drives a motor. The motor driver comprises: a storage unit that stores the quantity of heat generated independently of the value of a current I[Arms] caused to flow in the motor as a generated heat quantity a[W]; a current detection unit that detects the value of the current I[Arms] caused to flow in the motor; and a heat quantity calculation unit that calculates the quantity of heat P[W] released to the interior of the power magnetics cabinet by adding the heat quantity a[W] stored in the storage unit and a heat quantity q×K[W/Arms]×I[Arms] responsive to the value I[Arms] detected by the current detection unit.

Abstract: A method for detecting a reverse current in a switching structure supplying power to an inductive load, having at least one switch and linked to an electric power source and to a ground for a control phase in which the current from the source supplies power to the load in accordance with a given duty cycle and a freewheeling phase in which the induced current from the load is decreasing, the reverse current being liable to be created during a freewheeling phase following a high duty cycle in a previous control phase creating a counter-electromotive force (cemf). The cemf is approximated proportionally to the integration of the duty cycle (integ[Dut cycl]) as a function of time (t), the reverse current either being calculated as a function of the estimated cemf or a reversal of the current criterion being established.

Abstract: A power conversion apparatus includes a power conversion circuit and a control unit. The power conversion circuit converts electric power supplied from a power supply and outputs the converted electric power. The control unit controls the power conversion circuit. The power conversion circuit has at least one phase that is configured as a parallel-connection phase in which two semiconductor elements are connected in parallel to each other in each of an upper arm connected to a high potential-side wiring of the power supply and a lower arm connected to a low potential-side wiring of the power supply. The control unit detects temperature information related to element temperatures of all of the plurality of semiconductor elements of a target arm that is either of the upper arm and the lower arm of the parallel-connection phase, and performs overheating protection control of the power conversion circuit based on the detected temperature information.

Abstract: System and method for regulating a power conversion system. An example system controller for regulating a power conversion system includes a signal generator and a driving component. The signal generator is configured to receive a feedback signal associated with an output signal of a power conversion system and a current sensing signal associated with a primary current flowing through a primary winding of the power conversion system and generate a modulation signal based on at least information associated with the feedback signal and the current sensing signal. The driving component is configured to receive the modulation signal and output a drive signal to a switch based on at least information associated with the modulation signal.

Abstract: A hydraulic fracturing system includes a pump, an electrically powered motor for driving the pump, a trailer on which the pump and motor are mounted, and a transformer that steps down electricity for use by the motor. Electrical output from the transformer connects to a series of receptacles mounted onto a housing around the transformer. A similar set of receptacles is provided on the trailer and which are electrically connected to the motor. Power cables equipped with plugs on their opposing ends insert into the receptacles to close an electrical circuit between the transformer and pump.

Abstract: An electrical appliance with a resonant motor for driving a vibratory component is provided that has a control unit for driving the resonant motor with a predetermined driving frequency and for measuring the motion-induced voltage of the resonant motor and for determining whether the measured voltage value coincides with a predetermined target voltage value or whether the measured voltage value has crossed over the predetermined target value. The control unit measures the motion-induced voltage at a predetermined time of measurement (tm) within a driving cycle.

Abstract: A power supply circuit that includes a voltage conversion circuit (CONV) for outputting an output voltage to an output voltage terminal, the output voltage being stepped up or stepped down from an input voltage (VIN) presented to an input voltage terminal, an output capacitor (COUT) coupled to the output voltage terminal, and a charge extraction circuit for extracting the charge of the output capacitor (COUT). Quick response to overshoot of VOUT generated by a sudden reduction in load current (ILOAD) is afforded, and overshoot is minimized.

Abstract: A protective redundancy circuit is provided for a power tool having an electric motor. The protective redundant subsystem is comprised of: a motor switch coupled in series with the motor; a motor control module that controls the switching operation of the motor switch; and a protective control module that monitors switching operation of the motor switch and disables the power tool when the switching operation of the motor switch fails. In the context of an AC powered tool, the switching operation of the motor switch is correlated to and synchronized to the waveform of the AC input signal. During each cycle or half cycle, the motor control module introduces a delay period before closing the motor switch and the protective control module determines the operational status of the motor switch by measuring the voltage across the motor switch during the delay period.

Abstract: A circuit arrangement for de-exciting an excitation winding of a synchronous machine in the event of a fault, including a control circuit for controlling a current flow through the excitation winding, it being possible to apply a positive control voltage to the excitation winding for excitation and a negative control voltage for rapid de-excitation, and including a protective circuit which is parallel-connected to the excitation winding and which does not permit a current flow over the protective circuit in the event of rapid de-excitation and which forms a current path for limiting the voltage and de-exciting the excitation winding if at least one connecting line between the control circuit and the excitation winding is interrupted.

Abstract: An apparatus for controlling a high-power drive device external to a package of a motor drive circuit includes a motor drive circuit. The motor drive circuit includes a driver to control the high-power drive device based on a first reference voltage, a second reference voltage, and a control signal based on a received control signal. A fault circuit generates a failure indicator based on a voltage across terminals of the high-power drive device. A fault condition is based on the failure indicator. A first terminal coupled to the driver charges a node of the high-power drive device over a first length of time in response to an absence of the fault condition and a first level of the control signal. A second terminal coupled to the driver discharges the node over a second length of time different from the first length of time.

Abstract: Systems and methods for monitoring excitation of a generator based on a faulty status of a generator breaker are provided. According to one embodiment, a system may include a controller and a processor communicatively coupled to the controller. The processor may be configured to receive, from a contact associated with a generator breaker, a reported status of the generator breaker, receive operational data associated with one or more parameters of a generator associated with the generator breaker, and correlate the reported status of the generator breaker and the operational data. Based on the correlation, the processor may establish an actual status of the generator breaker, and, based on the actual status, selectively modify a mode of excitation of the generator.

Abstract: A vibration generating apparatus with high yield, low cost, and can exhibit vibration tactile haptic effects even with variation in the natural frequency of a mechanical vibrator, including a damping system having a damping ratio ?<1 to support a mechanical vibrator to a fastening part, and a magnetizing unit generating a dynamic magnetic field to vibrate the mechanical vibrator by non-contact, the mechanical vibrator generating a beat vibration by making the frequency of a drive voltage applied to the magnetizing unit, from a drive start or middle of drive, to be a non-resonant frequency out of a damped natural frequency of the mechanical vibrator, wherein the apparatus comprises a forced vibration control unit controlling to stop application of the drive voltage, in a beat wave defining an amplitude of the beat vibration, at a second valley part after a first peak part from the side of the drive start.

Abstract: A suppression circuit may be added to a motor driver circuit, which suppresses offset voltage and ringing in the output signal. The suppression circuit may include an RC circuit filter connected to a pin of a microchip providing a gating reference signal and a junction between high and low side MOSFETS connected to the microchip.

Abstract: A compressor is provided and includes a single-phase electric motor and a protector device. The electric motor drives a compression mechanism and has a rotor and a stator. The stator is comprised of aluminum windings. The protector device is attached to the stator and is configured to disconnect the electric motor from a power supply when an input voltage of the power supply to the electric motor is less than a threshold voltage value set at a level between a minimum run voltage and an overheat voltage of the compressor. The overheat voltage corresponds to an overheat temperature of the electric motor. The threshold voltage value is set at a level that is between the minimum run voltage and the overheat voltage. The protector device includes a tolerance level such that the threshold voltage minus the tolerance level is greater than the overheat voltage and the threshold voltage plus the tolerance level is less than the minimum run voltage.

Abstract: A method includes receiving N power signals, each having a different one of N phases, over N power supply lines, where N is an integer greater than two. The method further includes selectively activating a first switch to allow a first current to flow from a first one of the N power supply lines to a second one of the N power supply lines. The method includes generating a signal based on the first current, and selectively generating a phase failure signal when the signal is less than a predetermined threshold.

Abstract: A power-protection apparatus is provided.

Abstract: A motor control device for controlling a three-phase brushless motor that has a rotor and field coils includes: a load range determining unit that determines a rotor rotation angle range, in which the three-phase brushless motor becomes a load, as a load range when a short-circuit fault occurs in one of a plurality of switching elements. The load range determining unit determines a rotor rotation angle range, in which load current is presumed to flow through a closed circuit formed of the short-circuit switching element and any one of regenerative diodes connected in parallel with the respective normal switching elements when the rotor is rotated in a state where all the switching elements other than the short-circuit switching element are turned off, as the load range.

Abstract: Protection of a motor controller from a transient voltage and/or an over-voltage condition is described. A drive circuit includes a rectifier portion and at least one inductive device coupled to the rectifier portion. The drive circuit further includes at least one voltage clamping device coupled in parallel with the at least one inductive device, and at least one switching device configured to open as a function of a direct current (DC) link voltage value.

Abstract: A bi-directional electrostatic discharge (ESD) protection device may include a substrate, an N+ doped buried layer, an N-type well region and two P-type well regions. The N+ doped buried layer may be disposed proximate to the substrate. The N-type well region may encompass the two P-type well regions such that a portion of the N-type well region is interposed between the two P-type well regions. The P-type well regions may be disposed proximate to the N+ doped buried layer and comprise one or more N+ doped plates and one or more P+ doped plates.

Abstract: A suppression circuit may be added to a motor driver circuit, which suppresses offset voltage and ringing in the output signal. The suppression circuit may include an RC circuit filter connected to a pin of a microchip providing a gating reference signal and a junction between high and low side MOSFETS connected to the microchip.

Abstract: A motor drive apparatus includes a back EMF detection element and a protection control circuit. When a voltage detected by the back EMF detection element exceeds a threshold voltage of a Zener diode, a voltage signal is applied to a sensing gate through a detection signal line to sequentially turn on switching element of the low-side arm. A current caused by the back EMF applied to a drive circuit flows to the ground through the switching element of the low-side arm in an on-state. Thus a braking torque is applied to a motor, which is driven to rotate by an external force, and hence the back EMF is reduced. Switching elements in the drive circuit are thus protected from the excessive voltage.

Abstract: The invention relates to a protective circuit (10) in a screen wiper drive (1), consisting of a parallel circuit having two circuit elements (16, 17), wherein one circuit element (16) consists of a capacitor (18) and the other circuit element (17) consists of a series-connection of a diode (19) and a Zener diode (20), wherein the forward direction of the diode (19) and the Zener diode (20) is different and the Zener diode (20) inhibits in the direction of a plus pole.

Abstract: A motor drive circuit includes a positive and a negative supply rail for connection to a battery (104), a motor drive circuit including a plurality of motor drive subcircuits which each selectively permit current to flow into or out of a respective phase of a multi-phase motor (101) in response to control signals from a motor control circuit, and a switching means including at least one switch which is in series with a respective phase of the motor which is normally closed to permit the flow of current to and from the subcircuit to the respective motor phase. A fault signal detecting means (160) detects at least one fault condition and, in the event of a fault condition being detected, causes the at least one switch to open. A snubber circuit (150) is associated with the motor and is arranged so that following the opening of the switch, energy stored in the motor windings is diverted away from the switching means through the snubber circuit to the battery.

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 circuit arrangement for de-exciting an excitation winding of a synchronous machine in the event of a fault, including a control circuit for controlling a current flow through the excitation winding, it being possible to apply a positive control voltage to the excitation winding for excitation and a negative control voltage for rapid de-excitation, and including a protective circuit which is parallel-connected to the excitation winding and which does not permit a current flow over the protective circuit in the event of rapid de-excitation and which forms a current path for limiting the voltage and de-exciting the excitation winding if at least one connecting line between the control circuit and the excitation winding is interrupted.

Abstract: A method is provided for controlling operation of an air conditioning unit. The method comprises supplying line voltage to activate a motor configured to operate the air conditioning unit, and monitoring a supply of control voltage in order to control operation of the air conditioning unit, the supply of control voltage being derived from line voltage. In response to detecting a control voltage below a predetermined threshold and/or by a predetermined percentage, a time delay is initiated. The method further comprises deactivating the motor if a predetermined increase in control voltage is not detected before the time delay expires.

Abstract: The motor monitoring system of the present disclosure uses several calculated monitoring values to determine a status of a motor and take a predetermined action when a threshold corresponding with the monitoring value is exceeded. The threshold may be calculated by an intelligent electronic device (IED) monitoring the motor. The predetermined action may include further monitoring of the motor. The predetermined action may include monitoring equipment not directly monitored by the IED.

Abstract: A protective circuit arranged on a Printed Circuit Board (PCB) has two conductor loops. At least one supply voltage track, at least one semiconductor switch and at least one control component are arranged on the PCB. A first terminal of the control component and a first terminal of the semiconductor switch are connected electrically. A first conductor loop of the protective circuit is arranged on the PCB so that it surrounds an electrically conducting connection between the supply voltage track and the semiconductor switch and/or the control component. A second conductor loop is arranged on the PCB so that it surrounds the electrically conducting connection between the first terminal of the control component and the first terminal of the semiconductor switch, and thereby screens the same from the semiconductor switch and at least from those regions of the control component that are also connected to the supply voltage track.

Abstract: A torque limit section that applies limit to a torque instruction value of an electric motor such that a switching elements temperature is restricted to no more than an element upper limiting temperature includes a torque restriction section that finds a torque restriction value for restricting the torque of the electric motor in accordance with the said switching elements temperature; a torque restriction mitigation section that finds a torque restriction mitigation value for mitigating the torque limit value in accordance with the integrated value of the deviation of the element upper limiting temperature and the switching elements temperature; a first subtractor that finds a torque restriction value by subtracting the torque restriction mitigation value from the torque limit value; and a second subtractor that finds a limited torque instruction value obtained by subtracting the torque limit value from the torque instruction value and outputs this to the gate generating section.

Abstract: An electric motor control circuit includes an electric energy storage device electrically connected via DC power buses to an inverter circuit that connects via an alternating current circuit to an electric machine. A capacitive shunt circuit connects between the power buses. Current flow through the capacitive shunt circuit to the chassis ground is monitored. A fault is identified when the current flow through the capacitive shunt circuit to the chassis ground exceeds a threshold.

Abstract: Detection accuracy of a short circuit state in a load driving circuit is improved thereby operation efficiency of a motor may be enhanced. A gate control circuit 25 turns off NMOS transistors Q1 and Q4, turns on an NMOS transistor Q3, and turns on and off an NMOS transistor Q2 intermittently so as to control rotation of a motor 10. A detection circuit 30a detects a voltage Va at a connection node a between the NMOS transistor Q2 and the motor 10 a predetermined time after the NMOS transistor Q2 is turned on. A control circuit 20 turns off the NMOS transistor Q2 so as to cut off a current from a power supply to the motor 10 if the voltage Va at the connection node a is within a range in which the motor 10 is determined to be short-circuited.

Abstract: In a steering control unit, a U-phase feed line branches into paired branch feed lines, phase-open MOSFETs are provided in middle portions of the branch feed lines, phase-open MOSFETs are provided in middle portions of a V-phase feed line and a W-phase feed line, and the phase-open MOSFETs are arranged in such a manner that parasitic diodes are in the same orientation with respect to a motor. When an abnormality occurs, all the phase-open MOSFETs are turned off. Then, a closed circuit, which includes phase coils and through which electric currents flow, is no longer present.

Abstract: An electric vehicle includes a control unit having overcurrent generation judgment unit, inverter selection unit, and inverter drive control unit. The overcurrent generation judgment unit judges whether an overcurrent is generated in an inverter for generation or an inverter for travel. When an overcurrent is generated in one of the inverters, the inverter selection unit selects the other inverter to be driven. The inverter drive control unit stops the driving of the one inverter and drives the other inverter to drive a travel motor or a generator.

Abstract: A driving device includes a motor, a clutch gear, a first rotating portion, a second rotating portion, a piezoelectric assembly, and a controlling unit. The motor includes a rotating shaft. The clutch gear is fixed to the rotating shaft. The first rotating portion sleeved on the rotating shaft includes a first end meshing with the clutch gear and a second end opposite to the first end. The second rotating portion is engaged with the second end. The piezoelectric assembly is sandwiched between the second end and the second rotating portion. The controlling unit is electrically connected to the motor and the piezoelectric assembly. The controlling unit is configured for storing a predetermined voltage, and determining whether a voltage output by the piezoelectric assembly equals to or exceeds the predetermined voltage. A protection method for the driving device is also provided.

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

Abstract: A method and a circuit are provided for the commutation of brushless direct-current motors (BLDC motors), without using sensors, and especially to a method and a circuit for producing rotor position signals, without using sensors, for the commutation of brushless direct-current motors. In the method and the circuit Hall sensor signals are emulated without sensors and rotor position signals free of disturbing pulses and with a correct phase position are generated from said signals. The rotor position signals can be used to carry out a reliable, sensor-free commutation.

Abstract: A motor control center communication system configured to interface with a communication network. The system includes a plurality of motor control units (MCUs), and a MCU controller configured to transmit and receive data signals via the communication network to and from, the plurality of MCUs. Each of the plurality of MCUs includes a magnetic contactor having electrical contacts operable between open and closed positions, and a local control module operatively connected to the associated magnetic contactor and to the MCU controller, and configured to monitor a status of the electrical contacts, transmit the monitored status information to the MCU controller, and actuate the associated magnetic contactor based on data signals received from the MCU controller.

Abstract: A power limiting system for multiple electric motors includes an electrical power generating component, such as an alternator, and a plurality of motor controllers connected to an electrical bus. Each motor controller compares the voltage on the bus to a specified minimum voltage and a specified maximum voltage, and reduces its electric power output if the voltage on the bus is less than the maximum voltage while continuing to operate the electric motors.

Abstract: A motor control circuit (MC) comprising input terminals (IT1, IT2) to receive a rectified input voltage (Vrm), and output terminals (OT1, OT2) to supply a motor drive signal (Vm). A switching circuit (1) is alternately in an on-state (Ton) and an off-state (Toff) for intermittently coupling the input terminals (IT1, IT2) to the output terminals (OT1, OT2). A controller (2) controls the switching circuit (1) to be (i) in the on-state (Ton) during a first period in time (T1) when an amount of magnetic saturation of the motor is smaller than a predetermined value, and (ii) alternately in the on-state (Ton) and the off-state (Toff) to obtain a pulse width control of the motor drive signal (Vm) during a second period in time (T2) when the amount of magnetic saturation of the motor is larger than the predetermined value.

Abstract: A modular control assembly is provided for on-machine control of a desired machine. One embodiment has a machine mountable base and a replaceable control unit, wherein the machine mountable base has a machine protection device. In various embodiments of the machine mountable base, the machine protection device may have a short-circuit protective device and a disconnect device. In addition, various embodiments of the replaceable control unit may have a variable frequency drive, a soft start device, or an adjustable overload protection device.

Abstract: The present invention relates to a motor controller for air conditioner including a converter having at least one switching element for converter, the converter converting AC utility power into DC power by a switching operation of the switching element; an inverter having at least one switching element for inverter, the inverter converting the DC power into prescribed AC power by a switching operation of the switching element and driving a three-phase motor; a microcomputer outputting a converter switching control signal that controls the switching element for converter; and a dc terminal signal generator detecting a dc terminal voltage that is applied across an dc terminal of the converter to sequentially generate a pulse type dc terminal signal, and insulating the dc terminal from the microcomputer. The present invention may sequentially generate a dc terminal signal and simultaneously insulate the dc terminal from the microcomputer, thus making it possible to improve the stability of the motor controller.

Abstract: A load control apparatus outputs a PWM signal to a switching element to control a load. The switching element is connected between a power supply and a grand in series with the load. An abnormal increase detecting unit outputs an abnormal increase detection signal when detecting abnormal increase in applied voltage, which is applied to the load, relative to target voltage. An abnormal decrease detecting unit outputs an abnormal decrease detection signal when detecting abnormal decrease in the applied voltage relative to the target voltage. An operating state monitoring unit outputs a normally operating signal when the load normally operates. A signal combining unit generates a combined signal by combining the abnormal increase detection signal, the abnormal decrease detection signal, and the normally operating signal and outputs the combined signal via a common signal output terminal.