Abstract: A motor driver includes an H-bridge having a first differential input, a second differential input, and a differential output; a sensing circuit coupled to the differential output of the H-bridge; a comparison and logic circuit coupled to the sensing circuit; a pair of pre-driver circuits coupled to the comparison and logic circuit for driving at least one of the differential inputs of the H-bridge; and a pair of level shifters coupled between the comparison and logic circuit and the sensing circuit. The pair of level shifters is used to assure that the VGS of a pair of serially coupled transistors in the sensing circuit do not change with temperature, motor current, or voltage, and each includes a transistor receiving a reference current. The pair of level shifters each further includes a serially coupled diode and zener diode for preventing current from flowing from the differential output of the H-bridge to the level-shifting transistor.

Abstract: A heating value calculation part obtains a substantial heating value based on the difference between a heating value and a radiating value attributed to a motor supply current. The radiating value is obtained by a difference between a motor estimation temperature Td and an ambient temperature Tm. The heating value is cumulated in the heating value calculation part and the cumulated value is inputted to a cumulated buffer. A cumulated value TS which is obtained by adding an initial temperature T0 to the cumulated value Td is inputted to a target current value ratio map and a target current value upper limit map. One of the target current values is selected and the selected target current value is inputted to a current feedback control part. The current feedback control part controls a motor output part such that the motor supply current is converged to the target current value.

Abstract: A power management module for a winch system comprises an overload and low voltage interrupt module within a housing. The overload interrupt determines operating current for the winch system and provides an interrupt signal when the current is greater than a threshold. The low voltage interrupt determines voltage of a power source and provides an interrupt signal when the voltage is less than a threshold. A method of operating the power management module comprises determining operating current of the winch system with an overload interrupt module and voltage of a vehicle power source with a low voltage interrupt module. The overload and low voltage interrupt modules are located within a housing. The overload interrupt provides an interrupt signal when the operating current is greater than a threshold. The low voltage interrupt provides an interrupt signal when the voltage is less than a threshold.

Abstract: A protecting device for multi-motors driven by motor driving circuits for operating motors includes a comparison module, an operative logic module and a control module. The comparison module determines whether or not an abnormal over current occurs in the motors. The operative logic module receives a determination result of the comparison module and outputting a motor control signal to the motor driving circuit and a notice signal to the control module. If an over current occurs in the motor, the motor control signal outputted from the operative logic module will be a disable signal for stopping the operation of the motor driving circuit and the motor. The control module outputs a warning signal based on the notice signal to notify users about the operating status of the motor. Therefore, the present invention can prevent the motor driving circuit and the motor from being damaged by an over current.

Abstract: A clothes dryer includes a motor adapted to be mounted on a frame of the dryer for driving a dryer belt to rotate a drum of the dryer. The motor includes a rotor adapted to rotate the belt, at least one winding energizable to cause rotation of the rotor, and a first switch operable to control energization of the winding. A second switch has a sensor for sensing belt breakage. The second switch is mounted on the first switch and is electrically connected to the winding so that when the belt is no longer sensed, the second switch stops operation of the winding and thereby stops rotation of the rotor.

Abstract: A motor starter is disclosed. The motor starter includes control circuitry integrally arranged with at least one current path and a processor included in the control circuitry. The motor starter further includes at least one processor algorithm residing on the processor, the at least one processor algorithm containing instructions to monitor characteristics of current on the at least one current path and to provide data pertaining to a condition of the at least one current path. The motor starter further includes a micro electromechanical system (MEMS) switch disposed on the at least one current path, the MEMS switch responsive to the control circuitry to facilitate the control of an electrical current, passing through the at least one current path.

Abstract: A motor driving circuit includes an inverter circuit including switching devices connected in a bridge manner, electric-current detection resistances connected between the lower switching devices in the inverter circuit and the ground, so as to enable detection of the phase currents with the electric-current detection resistances, a PWM circuit which controls ON/OFF of the switching devices and repeatedly causes powering and regenerative time intervals, by alternately turning on and off the upper switching devices and the lower switching devices. During a time interval during which the lower switching devices, the electric-current detection resistances and the motor constitute a closed circuit and a regenerated electric current flows through the circuit, when the electric current values detected are equal to or greater than a predetermined electric current value, it is determined that a ground fault has occurred in the connection lines between the inverter circuit and the motor.

Abstract: A counting unit counts a current supplying duration for a component which determines a life of a device. A prediction unit predicts the device life based on an integrated current supplying duration integrated by the counting unit and a lifetime of the component. A monitoring unit monitors an efficient operating condition of the device based on a prediction signal outputted from the life prediction unit. The counting unit and the life prediction unit is provided at a short-life fan and a long-life component respectively, and the life prediction unit predicts the life of the device based on information on the short-life fan and the long-life component.

Abstract: Inverters, based on signals from a control device, generate a commercial AC voltage across neutral points of 3-phase coils. A Y-capacitor for removing noise is connected to a load outside the vehicle receiving the supply of the commercial AC voltage. A relay connected in series with a leakage detecting device is provided inside the vehicle. The relay is turned off when a plug of the load outside the vehicle is connected to a connector, and prevents a leakage current from flowing via a ground.

Abstract: In controlling a seatbelt retracting device having a mechanism for retracting a seatbelt with a motor, a current flowing to the motor is detected, and a rate of increase in the current is calculated. The motor is stopped when the rate of increase in the electricity exceeds a predetermined rate and when the electricity exceeds a predetermined value, respectively.

Abstract: A motor starter is provided. The motor starter includes micro-electromechanical system switching circuitry. The system may further include solid state switching circuitry coupled in a parallel circuit with the electromechanical switching circuitry, and a controller coupled to the electromechanical switching circuitry and the solid state switching circuitry. The controller may be configured to perform selective switching of a load current from a motor connected to the motor starter. The switching may be performed between the electromechanical switching circuitry and the solid state switching circuitry in response to a load current condition appropriate to an operational capability of a respective one of the switching circuitries.

Abstract: A thermal overload protection for an electrical device, particularly an electric motor (M), measures a load current supplied to the electrical device (M), and calculates the thermal load on the electrical device on the basis of the measured load current, and shuts off (S2) a current supply (L1, L2, L3) when the thermal load reaches a given threshold level. The protection comprises a processor system employing X-bit, preferably X=32, fixed-point arithmetic, wherein the thermal load is calculated by a mathematic equation programmed into the microprocessor system structured such that a result or a provisional result never exceeds the X-bit value.

Abstract: Provided is a method and apparatus for controlling a motor of a disk drive. The method is used to stably control the startup current of a motor by considering a voltage drop and the disk drive uses the method. The method includes managing power-on reset retry information generated during the startup of the motor and determining the startup current of the motor that corresponds to a power-on reset retry count included in the power-on reset retry information.

Abstract: A robot control system including a servo amplifier supplying power to a robot, a processor controlling the operation of the robot, and a servo power connection/cutoff circuit connected to the same, issuing excitation/nonexcitation commands to a charging relay and a main circuit connection electromagnetic contactor provided in the circuit from the processor, monitoring the opened/closed states of the contacts of the charging relay and main circuit connection electromagnetic contactor by the processor, and detecting if their contacts open and close as instructed by the processor to thereby check if the power connection/cutoff circuit has a fault. Due to this, it is possible to provide a robot control system which detects faults of the power connection/cutoff circuit and which is inexpensive and high in safety.

Abstract: A control device for soft starting and protecting overload of a motor in a power tool is disclosed. The control device comprises a power switch, a varistor, several diodes, several resistors, several capacitors, a relay, a transistor, a triac, and a microcontroller. The microcontroller is embedded with program such that, after the power switch is turned on, the microcontroller generates a smooth soft start voltage to drive the power tool. With the characteristics of power-control device, the voltage sent to motor is increased from low to full range. When the speed of motor is increased from low to the maximum, the microcontroller turns off the power-control device and turns on a relay.

Abstract: As an antilock system for a permanently excited electric motor drive, especially for a steering booster servo drive of a motor vehicle, in the event of a winding short-circuit, an interruption of at least one winding phase (MP1 or MP2 or MP3) of the winding affected by the short circuit is provided, by a separating means (T) triggered by an explosion directly or indirectly by the winding short-circuit. The antilock system advantageously has a separate neutral point connection part (MP) which is especially embodied as a sheet metal moulded part, is to be connected to the winding ends of the electric motor, and contains the winding phases (MP1; MP2; MP3) and the neutral point connection thereof as a single component. The antilock system is purposefully arranged on a front winding head of the electric motor and connected to the winding thereof.

Abstract: There is provided an AC motor controller capable of detecting an abnormal state of a motor cable while an AC motor is operating without using a special circuit but using a processor. The AC motor controller includes an AC motor; an inverter for driving the AC motor with a motor current through a motor cable; and a motor current detector for detecting the motor current flowing in the motor cable of the AC motor, in which a processor detects an abnormal state of the motor cable such as an inter-phase short circuit and an open circuit based on the motor current detected by the motor current detector.

Abstract: An overload current control circuit for a DC motor comprises: a DC motor, a DC power source, a power semiconductor assembly, and a sampling resistor that are connected in series. The overload current control circuit further comprises a voltage polarity switching circuit that is connected to a circuit between the sampling resistor and the overload protection and detection circuit to control the single polarity of the sampling voltage of the first and second terminals of the sampling resistor, so as to provide constant voltage potential to the overload protection and detection circuit, thus providing overload protection to the DC motor.

Abstract: A system for sensing short circuits and open circuits prior to operation of a motor (i.e., while the motor is in a static state), thereby sparing the electrical system from destructive effects of these electrical problems. In addition, the system may detect a short circuit during operation of the motor (i.e., while the motor is in a dynamic state). Still yet, the system may detect an open circuit at the motor. The motor may be any electromechanical motor, such as a direct current (DC) motor, used in a vehicle or otherwise for controlling motion of a mechanical device.

Abstract: There are provided upper and lower switching elements 1U to 1W and 2U to 2W for energizing motor drive windings 4U to 4W, a control circuit 20 that starts outputting a control signal for energization based on an energization instruction, pre-drive circuits 8U to 8W and 9U to 9W for controlling ON/OFF of the upper and lower switching elements based on the control signal, and short circuit detection circuits 10U to 10W for detecting short circuits in a node 14 between the upper and lower switching elements to higher-potential and lower-potential power sources based on the control signal and a voltage of the node.

Abstract: An electronic trip unit for a motor circuit breaker of an electric motor includes at least one detection unit configured to sense at least one current that is delivered to the electric motor. The unit further including a discriminator circuit, the discriminator circuit being in a first state when no measured current value exceeds a predefined trip threshold, and being in a second state when at least one measured current value exceeds the predefined trip threshold. The discriminator circuit includes an output for controlling the motor; a voltage-limiting component having a breakdown voltage; a resistor; and a switching unit configured to, in the first state, switch the control signal to the first level, and, in the second state, switch the control signal to the second level, the switching unit being configured to be switched by a voltage drop across the resistor.

Abstract: A clamping circuit is included in a phased motor control circuit, particularly on an electrical connection connected to at least one electrostatic discharge cell and/or the driver control electronics of the phased motor control circuit. The clamping circuit triggers when a voltage that exceeds a clamping turn-on threshold occurs on the electrical connector, sourcing or sinking the discharge current so as to protect the electrostatic discharge cells and/or driver control electronics from destruction by said discharge current.

Abstract: A motor starter is disclosed. The motor starter includes control circuitry integrally arranged with at least one current path and a processor included in the control circuitry. The motor starter further includes at least one processor algorithm residing on the processor, the at least one processor algorithm containing instructions to monitor characteristics of current on the at least one current path and to provide data pertaining to a condition of the at least one current path. The motor starter further includes a micro electromechanical system (MEMS) switch disposed on the at least one current path, the MEMS switch responsive to the control circuitry to facilitate the control of an electrical current, passing through the at least one current path.

Abstract: A method and an apparatus that permit the measurement of the motor average current directly from the output of the amplifier and filter stage used for instantaneous dc-link overcurrent protection. As such, only one amplifier and filter stage is sufficient to provide both the motor average current and instantaneous dc-link overcurrent protection. The invention permits the suppression of the amplifier and filter stage that is typically used to derive the motor average current directly from the dc-link current.

Abstract: When a failure of an electric current flow occurs in any one of phases, a microcomputer calculates a d-axis current command value that changes along a tangent curve with predetermined rotation angles as asymptotic lines. The microcomputer continuously outputs a motor control signal using two phases other than the phase with the failed electric current as electric current flowing phases by performing current feedback control in correspondence with the d-axis current command value. In such two-phase drive operation, the microcomputer calculates the d-axis current command value and a q-axis current command value in such a manner that the phase current values of the electric current flowing phases become constant at respective maximum values of flowable electric currents, which are set for the phases, in rotation angle restriction ranges in which the phase current values need to be restricted in correspondence with the maximum values, or electric current restriction ranges.

Abstract: A motor driver having over current detection circuitry includes an H-bridge having a first differential input, a second differential input, and a differential output; a sensing circuit coupled to the differential output of the H-bridge; a comparison and logic circuit coupled to the sensing circuit; a pair of pre-driver circuits coupled to the comparison and logic circuit for driving at least one of the differential inputs of the H-bridge; and a pair of level shifters coupled between the comparison and logic circuit and the sensing circuit. The H-bridge includes a first side having a first transistor coupled to a second transistor, and a second side having a third transistor coupled to a fourth transistor. The first and third transistors are power PDMOS transistors, and the second and fourth transistors are power NDMOS transistors.

Abstract: A current detector (60) samples a motor current (MCRT_A) from a controlling sensor and a motor current (MCRT_B) from a monitoring sensor, and holds respective motor current maximum values (MCRT_Amax, MCRT_Bmax) at each prescribed operation cycle. An abnormality determiner (62a) detects that the motor current maximum value (MCRT_Amax) is in GND short-circuiting range and that the current difference between the maximum values exceeds a prescribed threshold value at each of successive operation cycles, to thereby determine an abnormality of the controlling sensor. Then, the abnormality determiner (62a) generates a detect signal (DET) specifying the current sensor abnormality and outputs it to a relay driver (64) and an alarm (66). Relay driver (64) receives the detect signal (DET) and generates a signal (SE) to turn off a system relay. The alarm (66) generates a signal (AL) and outputs it to display means arranged outside a power supply apparatus.

Abstract: A central vacuum cleaning system control subsystem for use in a central vacuum cleaning system having a motor includes a central vacuum unit control module with a receiver for wirelessly receiving command signals, and a power stage for controlling the motor in accordance with command signals received through the receiver. The control module is stable in high ambient temperature. Current flowing to the motor is sensed, and motor overcurrent and undercurrent conditions are determined. The control module determines when the motor is in an overcurrent condition. Power stage has a triac for controlling power to the motor. The control module also has a microprocessor that compares the current sensed against a normal operating current to determine overcurrent condition. Power to motor ceases when overcurrent condition exists. A generator is powered by air flow in a cleaning system for production of electrical energy.

Abstract: The invention relates to a method for detecting an overload in an electric hand tool (10) comprising an electric motor (12), in particular a battery-driven electric hand tool (10). According to the invention, an operating current (iB) of the electric motor (12) is determined, the difference (ID) between the value of the operating current (IB) and at least one stored current value (IG) is determined and a thermal overload of the electric hand tool (10) is deduced from said difference (ID). The invention also relates to a corresponding monitoring device (22).

Abstract: A motor starter is provided. The motor starter includes micro-electromechanical system switching circuitry. The system may further include solid state switching circuitry coupled in a parallel circuit with the electromechanical switching circuitry, and a controller coupled to the electromechanical switching circuitry and the solid state switching circuitry. The controller may be configured to perform selective switching of a load current from a motor connected to the motor starter. The switching may be performed between the electromechanical switching circuitry and the solid state switching circuitry in response to a load current condition appropriate to an operational capability of a respective one of the switching circuitries.

Abstract: A technique is provided for controlling operation of motors of different sized or ratings. Components used to apply and interrupt current to the motors may be shared in control devices for the different motors. The components may include contactors or circuit interrupters, and instantaneous trip devices. The components may be sized for the higher rated motors, and be oversized for the lower rated motors. Control circuitry permits the devices to be controlled in accordance with the characteristics of the particular motor to which the devices are applied, providing accurate circuit interruption while reducing the number of different components and component packages in a product family for the various motors.

Abstract: An over-current protection device is provided that uses a micro-controller to sense and interrupt current flow used by motors. Because the same micro-controller that is operating the motors may be used for the overall application current monitoring, no significant hardware overhead is incurred. The micro-controller uses two input/output pins to perform the sensing and control.

Abstract: In order to be acceptable for safety critical applications, it is necessary for an electrical machine to allow continued operation despite an electrical short circuit in one of the operational phases of that electrical machine. It will be appreciated that an electrical short circuit creates excessive electrical current through the short circuit with significant heating and other detrimental effects. However, the electrical machine can operate with one operational phase disabled. In such circumstances, the present invention incorporates means for determining an electrical short circuit has occurred and then injects an electrical current approximately equal to or greater than the rated electrical current. In such circumstances, the operational phase or coil 4, 24, 34 is effectively protected despite the electrical short circuit and hence the electrical machine can continue to operate.

Abstract: Various electrical apparatuses which include a current dampening device are disclosed. In one embodiment, an electrical apparatus is provided which includes a motor and a switch having an “on” position and an “off” position to control the operation of the motor. A current dampening device is connected in parallel with the motor downstream from the switch to dampen transient current. In another embodiment a ground fault circuit interrupter (GFCI) is electrically connected to the motor upstream from the switch.

Abstract: The present invention relates to a method and a system for controlling an asynchronous electric motor for detecting cabling errors between the electric motor and its starter, used in the windings of the motor. The electric motor (M) comprises three windings (U, V, W) distributed over three branches in delta configuration and is controlled by a starter (D) comprising power semiconductors directly connected in series within the three branches of the delta configuration of the windings (U, V, W). The method comprises the following steps: application of a voltage in a first branch of the delta, after a priming delay, priming of the semiconductor of the first branch, measurement of the electrical current generated within the first branch during the priming operation, determination of the configuration of the cabling of the first branch as a function of the measured electrical current.

Abstract: A specially designed rotation speed controller for fans, in addition to basic components like variable resistor, the controller has also been equipped with special components such as TRIAC, micro limit switch, and glass tube fuse, which allows said controller to precisely control the on/off status and the rotation speed of the fan, and the controller also provides power-off protection against power overload.

Abstract: A current detection unit starts sampling of a motor current at the timing when the motor current has exceeded a threshold value, and holds a maximum motor current value for each prescribed operation cycle. An abnormality determination unit determines whether the maximum motor current value is greater than the threshold value, and counts the number of times that the maximum motor current value continuously exceeds the threshold value. When the count value has reached at least 3, the abnormality determination unit generates and outputs a detection signal indicating abnormality in the motor current to a relay drive unit and a notification unit. The relay drive unit in receipt of the detection signal generates a signal to turn off the system relays. The notification unit generates and outputs a signal AL to display means outside the power supply apparatus.

Abstract: A compressor terminal fault interruption method and interrupter for disconnecting power to a compressor terminal when terminal venting failure is imminent including a current sensing circuit for sensing current provided to the terminal by a power source and outputting a sensed signal representing the current provided to the terminal and a control circuit. The control circuit includes a first circuit for outputting a reference signal representing input current much higher than locked rotor current, a second circuit connected to the current sensing circuit and the first circuit for comparing the sensed signal to the reference signal, and a third circuit connected to the second circuit for disconnecting power to the terminal when the sensed signal exceeds the reference signal, thereby preventing excessive current from reaching the compressor terminal.

Abstract: A motor overcurrent protection device connectable to a motor. The motor has a rotary shaft and a controlling port. The motor overcurrent protection device includes a sensing unit, a driving unit and a controlling unit. The sensing unit includes a magnetic block arranged on a circumference of the rotary shaft and a Hall device positioned beside the rotary shaft. The magnetic block is rotatable along with the rotary shaft to be instantaneously aligned with the Hall device. The driving unit is electrically connected with the controlling port of the motor. The controlling unit is electrically connected with the sensing unit and the driving unit. When the motor operates, each time the magnetic block is aligned with the Hall device, the Hall device outputs a pulse signal which is stored in the controller of the controlling unit. All the pulse signals are summed up in a preset sensing time of the controller.

Abstract: An objective is to detect a resolver malfunction without fail, using a low-cost resolver having the small number of the poles, and a control-motor system having advantage in small sizing and high-power outputting. In the control-motor system, the system for driving a 2m-pole motor based on a rotor rotation angle ? detected by a 2n-pole resolver, where m and n being counting numbers, is characterized in that: the sum of the square of a signal modulated by sin ? and the square of a signal modulated by cos ? in the resolver in which an excitation signal generated in said system is modulated by sin ? and cos ? in response to the rotor rotation angle ? of the resolver is compared to a predetermined malfunction threshold value, so that malfunction determination related to the resolver is performed, and also, given that the sum is a2 when the resolver is recognized to be in normal operation, the malfunction determination threshold value is made to be not smaller than {a×cos((?/2)/(m/n))}2.

Abstract: A liquid crystal display module arranged to improve brightness and light efficiency of a direct-below-type back light unit. The liquid crystal display module includes a plurality of lamps; a reflection plate arranged to accommodate the plurality of lamps; a plurality of first triangular protrusions protruded from the reflection plate between the lamps; a diffusion plate on the reflection plate; an optical film on the diffusion plate; and a liquid crystal display panel on the optical film.

Abstract: An object of the invention is to provide a break detection method capable of lessening a delay of motor power line break detection. According to the invention, in a motor power line break detection method of an AC servo driver including a current detector and a torque controller, a torque current component 9 is extracted from a three-phase AC detected by current detector 4, 5, a comparison is made between a torque command 1 and the torque current component 9, and if the difference between the torque command and the torque current component exceeds a setup value 21, it is recognized that a motor power line is broken.

Abstract: A fault protection system and method of fault protection for permanent magnet machine (PMM)-based systems that utilize machine neutral decoupling (MND) to shut down a shorted winding and/or to isolate a short-circuit fault to prevent damage to a permanent magnet machine and to any downstream components are provided. The invention may be used for high-reactance and/or high current PMM-based systems, such as are commonly found in industrial and aviation applications.

Abstract: A motor driving circuit includes an inverter circuit including switching devices connected in a bridge manner, electric-current detection resistances connected between the lower switching devices in the inverter circuit and the ground, so as to enable detection of the phase currents with the electric-current detection resistances, a PWM circuit which controls ON/OFF of the switching devices and repeatedly causes powering and regenerative time intervals, by alternately turning on and off the upper switching devices and the lower switching devices. During a time interval during which the lower switching devices, the electric-current detection resistances and the motor constitute a closed circuit and a regenerated electric current flows through the circuit, when the electric current values detected are equal to or greater than a predetermined electric current value, it is determined that a ground fault has occurred in the connection lines between the inverter circuit and the motor.

Abstract: In a rotation detection apparatus, a rotation-angle detector detects a rotation angle of a rotating body based on an output signal generated by a resolver. An exciting-signal generation circuit supplies an exciting signal for exiting the resolver to generate the output signal. An abnormality detection circuit detects an abnormality of an exciting-signal output terminal for outputting the exciting signal or an abnormality of an exciting-signal line for transmitting the exciting signal. A power-supply stopping circuit stops a power supply to the exciting-signal generation circuit when the abnormality detection circuit detects an abnormality of the exciting-signal output terminal or detects an abnormality of the exciting-signal line.

Abstract: In controlling a seatbelt retracting device having a mechanism for retracting a seatbelt with a motor, a current flowing to the motor is detected, and a rate of increase in the current is calculated. When the rate of increase exceeds a predetermined value, the motor is stopped. When the current exceeds a predetermined value, the motor is stopped as well.

Abstract: A motor overcurrent protection device connectable to a motor. The motor has a rotary shaft and a controlling port. The motor overcurrent protection device includes a sensing unit, a driving unit and a controlling unit. The sensing unit includes a magnetic block arranged on a circumference of the rotary shaft and a Hall device positioned beside the rotary shaft. The magnetic block is rotatable along with the rotary shaft to be instantaneously aligned with the Hall device. The driving unit is electrically connected with the controlling port of the motor. The controlling unit is electrically connected with the sensing unit and the driving unit. When the motor operates, each time the magnetic block is aligned with the Hall device, the Hall device outputs a pulse signal which is stored in the controller of the controlling unit. All the pulse signals are summed up in a preset sensing time of the controller.

Abstract: Control of an induction motor is carried out to limit damaging arcing stress and mechanical stresses placed on the control contactor assembly and the induction motor resulting from the simultaneous or synchronous breaking and making of contactors employed to connect the windings of the motor to a power supply. Asynchronously connecting the windings to the power supply via the asynchronous or non-simultaneous closing of the contactors of a modular contactor assembly reduces the potentially damaging transient current, the associated torque oscillations, and mechanical stresses. The present invention is particularly applicable to delta motors that are started with its windings in a star or wye configuration followed by the reconnection of the windings in a delta configuration when the motor is at normal running speed.

Abstract: According to the breaking detection processing, it is determined that (A) iu of AC current (absolute value) supplied to a motor is less than 0.5 amperes or iv thereof is less 0.5 amperes or iw thereof is less than 0.5 amperes, (B) the angular velocity of the motor is 1 rad/s or more and (C) at least any one of the current instruction values id*, iq* is 5 amperes or more in a step and then, a period in which all these three conditions (A)–(C) are satisfied at the same time is determined in another step. Consequently, it is determined that any one of the power supply lines in the motor is broken and a breaking detection flag is set to ON so as to detect the breaking.

Abstract: An apparatus for over current detection of a motor for use in a vehicle. This invention prevents the motor from burning out by more precisely detecting an over current of the motor within an overall drive area of the motor. This can be accomplished by setting, as an over current detection reference current, a predefined range between a normal current and a constraint current of the motor by drive input conditions of the motor, detecting a current of the motor flowing in a field effect transistor (FET) via a shunt resistor and a differential amplifier, and comparing the detected current with the over current detection reference current.