Abstract: A movable barrier operator includes a communication interface configured to receive commands that cause the motor to move the movable barrier. The movable barrier operator further includes a processing circuit configured to cause the motor to automatically move the movable barrier from a first open position toward a closed position and then from the closed position toward a second open position different from the first open position in response to receipt of an intermediate open command by the communication interface. The processing circuit can also cause the motor of the movable barrier operator to move the movable barrier toward the first open position in response to the processing circuit determining that the movable barrier had been obstructed while moving from the first open position toward the closed position.

Abstract: An apparatus can be used to control a door for a vehicle. A sensor unit is provided in the door and is configured to sense an object adjacent to a region outside of the door. A controller is configured to calculate a distance at which the object is positioned based on a signal received from the sensor unit and to control the door to be opened while the distance to the object is gradually reduced in a state where the door is closed, such that the object is sensed within a predetermined range.

Abstract: To provide an electric motor control system and an electric power steering apparatus that torque of the electric motor can be increased for ensuring of steering performance even at the time of abnormality occurrence. The controller is provided with 2 sets of control systems which control a supply current to each set of the windings. When abnormality occurs in one set of the windings and the control system, the electric motor control system sets 0 to supply current to all phase or partial phase windings of abnormality occurrence set, and increase supply current to normal set of the windings up to an irreversible current that increase an irreversible demagnetizing factor of the permanent magnet more than the normal time.

Abstract: A protection circuit for protecting a load, such as a winch motor, from an overcurrent as well as from a circuit fault including welded primary switch contacts and a failure of its MOS/FET component. A power MOS/FET is used as a current mirror for sensing load current. A secondary switch is series connected to control the primary switch. A control circuit including a programmable data processor controls the MOS/FET and the secondary switch and senses the current through the MOS/FET's secondary source terminal and senses the voltage at its primary source terminal. The programmable data processor determines whether an overcurrent exists by comparing the sensed power circuit current to a stored overcurrent value and also senses whether the contacts of the primary switch are welded closed and whether the MOS/FET has been damaged. Additional conditions are sensed. Application of power to the load is prevented when such conditions are detected.

Abstract: A system for adjusting the height of a patient support surface on a bed includes one or more height adjustment actuators operable to adjust a height of the patient support surface above a floor surface; a controller connected to the one or more height adjustment actuators, the controller including a memory; and one or more user interface units connected to the controller, wherein the controller is configured to record as a stored actuator state a current state of the one or more height adjustment actuators in the memory in response to a first input signal from the one or more interface units, and is configured to operate the one or more height adjustment actuators to automatically return them to the stored actuator state in response to a second input signal from the one or more interface units.

Abstract: A vehicle window lift control system includes a window lift motor, a motor drive/control module, an inverter, a rotor position sensing unit, and an anti-pinch module. The window lift motor is a brushless direct current motor. The anti-pinch module detennines whether or not the vehicle window is in an anti-pinch area based on position feedback signals generated by a rotor position sensing unit that is inherently included in the brushless direct current motor. When the vehicle window is in the anti-pinch area, an obstacle judgment unit is initiated. When there is an obstacle, an anti-pinch instruction unit sends an anti-pinch instruction to the motor drive/control module, and the motor drive/control module drives the inverter according to the anti-pinch instruction to make the motor rotate reversely. The present vehicle window lift control system has the advantages of small size, low failure rate and low cost.

Abstract: Electric motors may include one or more sensors usable to determine rotor alignment and/or speed. A method and apparatus for rotor alignment and/or speed error detection and/or correction are proposed, such as using signals from one or more sensors. A method and apparatus for controlling stator tooth activation based, at least in part, on corrections and offsets is also disclosed.

Abstract: A handheld work apparatus having an electric motor and a drive circuit for the electric motor. The rotation movement of the motor is converted into an oscillating movement of the work tool via a gear mechanism. The motor is situated in a circuit including at least the motor and a switch for operating the motor. To reduce wear of the gear mechanism, a control unit for operating the motor in one of two directions of rotation is provided. The control unit independently determines a selected direction of rotation for a next operating cycle as a function of a control variable. When the motor is started, the motor is started by the control unit in the direction of rotation which is associated with a value of the control variable. The control variable changes before the motor is restarted for a following operating cycle.

Abstract: A method for implementing a transition from a functioning steering assistance system to a deactivated steering assistance system when a fault occurs, comprising the following steps: establishing the fault of the steering assistance system; establishing that all high-side power switches are functional (first case), or establishing that all low-side power switches are functional (second case); and in the first case: opening all high-side power switches and performing PWM-like control of the low-side power switches; or in the second case: opening all low-side power switches and performing PWM-like control of the high-side power switches.

Abstract: A controller for an opening and closing member includes a driving mechanism, a detection portion, a control portion, and a determination portion. When the determination portion determines that the foreign matter exists in a period where the driving mechanism is operating, the control portion executes an interrupt operation to interrupt an operation of the driving mechanism. When the detection portion detects that the door is changed from the opening state to the closing state in a period from a time point before the determination portion determines that the foreign matter exists to a time point after the determination portion determines that the foreign matter exists, the control portion executes a restart operation to restart one of a first operation and a second operation that is the operation of the driving mechanism executed right before the interrupt operation.

Abstract: A system for connecting a single-phase generator in parallel with an inverter is disclosed. A signal corresponding to the angular position of the rotor in the generator is provided to the inverter, for example, from an angular position sensor connected to the rotor in the generator. Because variations in the load applied to the generator cause variations in the frequency of the power output by the generator, the inverter synchronizes the phase angle of the voltage output by the inverter to the angular position of the rotor.

Abstract: A motor system and a method of operating an electric motor that includes monitoring a voltage of power supplied to the motor by a mircrocontroller located in the motor; storing energy within the motor; detecting if the voltage drops below a nonzero threshold; and if the voltage drops below the threshold, immediately operating the microcontroller with the stored energy to store a state of the motor in non-volatile memory located within the motor, and ceasing operation of the motor. This motor operation may be employed with multiple motors in vehicles where voltage drop may occur during an engine start of a vehicle stop/start event.

Abstract: Systems and methods for safely powering an appliance user interface without external power are provided. One exemplary method includes receiving power generated by rotation of a rotor. The method further includes monitoring for the presence of a safety condition and disabling passive braking of the rotor when the safety condition is present such that the user interface of an appliance is powered. An exemplary washing machine can include a basket and a motor which includes a rotor, the motor being configured to rotate the basket by rotating the rotor. The washing machine can further include a user interface and a motor control circuit configured to drive the motor. The motor control circuit can be further configured to receive power generated by rotation of the rotor, monitor for the presence of a safety condition, and disable passive braking of the rotor when the safety condition is present.

Abstract: A control system for electrical equipment, the system including: a system controller; a motor; and a signal transducer. The system controller outputs a plurality of rotation switch signals, and the rotation switch signals are high-voltage AC signals. The motor is a brushless DC motor or electronically commutated motor (ECM). The signal transducer is connected between the system controller and the ECM, and includes a rotation switch sensing circuit, a microprocessor controller, and an interface signal processing circuit. The rotation switch sensing circuit detects the rotation switch signals output from the system controller, and transmits the rotation switch signals to the microprocessor controller for processing. The microprocessor controller is connected with the ECM via the interface signal processing circuit.

Abstract: An apparatus for controlling asymmetrical coasting of an endodontic reciprocating motor includes a controller operatively connected to the endodontic motor. The controller may include a processing unit that is configured to direct the rotation of the endodontic motor in the forward direction for a coast time and configured to direct the rotation of the endodontic motor in the reverse direction for a coast time. The forward coast time is separately calculated from the reverse coast time. A method for asymmetrically coasting a reciprocating endodontic motor includes rotating an endodontic motor in a forward direction and calculating a forward coast time for the forward direction and coasting the endodontic motor in the forward direction for the calculated forward coast time. After coasting the endodontic motor in the forward direction, the endodontic motor is rotated in a reverse direction. The reverse coast time is different than the forward coast time.

Abstract: A motor-driving device of an electric caulking gun has a micro-controller unit (MCU), a direction-changing module, a motor and a speed sensor. The direction-changing module and the speed sensor are electrically connected to the MCU. The direction-changing module is electrically connected to the motor, and the speed sensor detects a speed of the motor. The MCU is built in with a speed determination procedure comparing an actual speed of the motor acquired from the speed sensor with a preset speed. If the actual speed is lower than the preset speed, it indicates that the resistance at a tube nozzle of the electrical caulking gun increases and the direction-changing module increases the speed of the motor to maintain a preset caulk discharge rate. Given the motor-driving device, the operational inconvenience arising from the unstable caulk discharge rate of conventional electric caulking gun can be tackled.

Abstract: A motor-drive circuit includes: an output transistor configured to supply a drive current to a motor for a cooling fan; a switching-control circuit configured to control switching of the output transistor so that the motor rotates in a first direction, or rotates in a second direction opposite to the first direction; and a switching circuit configured to, when a first time has elapsed since start of rotation of the motor in the first direction, cause the switching-control circuit to start switching control so that the motor stops rotating in the first direction and thereafter rotates in the second direction, and configured to, when a second time has elapsed since start of rotation of the motor in the second direction, cause the switching-control circuit to start switching control so that the motor stops rotating in the second direction and thereafter rotates in the first direction.

Abstract: A control device for a hoist, which enables easy judgment of the lifetime of a brake of a hoist is provided. The time setting unit sets the time from startup of a double winding induction motor to disengagement of the brake and the time from start of engagement of the brake to stopping of the double winding induction motor in accordance with the time from the startup of the double winding induction motor to generation of torque. The time changing unit detects if power-supply frequency of a power supply is 50 Hz or 60 Hz and can change at least one of the time from the startup of the double winding induction motor to the disengagement of the brake and the time from stopping of driving of the brake to stopping of double winding induction motor in accordance with the power-supply frequency of the power supply.

Abstract: The driver seat unit and the other-seat unit are connected by the single signal line. A direction of a current passed through a motor is switched using contacts of a window opening switch and a window closing switch in the other-seat unit. When a window closing manipulation is performed by the driver seat unit, the current is passed through a coil of a relay via the contacts of the window closing switch, and a contact of the relay is switched to pass a forward current through the motor. When a window opening manipulation is performed by the driver seat unit, the current is passed through a coil of a relay via the contacts of the window opening switch, and a contact of the relay is switched to pass a reverse current through the motor.

Abstract: A trash can with a power operated lid can include a sensor assembly and a lifting mechanism. The sensor assembly can include at least one light emitter and at least one light receiver, the viewing area of the at least one light receiver being limited in size. The lifting mechanism can include a controller, a drive motor, and a lifting member. The trash can with power operated lid can further include at least one position sensor for detecting the position of the lid.

Abstract: A method of operating a rotary tool driven by a brushless motor including a DC brushless motor for rotationally driving a rotary bit, a torque setting clutch mechanism, a drive switch for drive-controlling a drive control circuit of the brushless motor, and a control means to rotationally drive the brushless motor by an operation of the drive switch and wherein the method includes a first step for stop-controlling of the drive control circuit, a second step for rotating forward or in reverse the brushless motor through the control and a third step for control-operating a semiconductor of an inverter circuit provided in the drive control circuit to short-circuit the magnetizing windings of the brushless motor, thus braking the rotor of the brushless motor and stopping the brushless motor.

Abstract: A control device for a vehicle includes: a charge control portion that adjusts an upper limit of charging power to a battery to prevent a negative electrode potential of the battery from dropping to a lithium reference potential, based on a charge/discharge history of the battery; a braking control portion that detects a sharing ratio between hydraulic braking force by a braking device and regenerative braking force for desired braking force according to a brake pedal depression amount so that a motor generator generates a regenerative braking force within a range of the adjusted upper limit of charging power; and a setting portion that variably sets, according to the hydraulic response rate detected by the detection portion, a degree of limitation of the upper limit when restricting charging current to the battery by restricting the upper limit.

Abstract: In a method and a device for determining a reference position of a locking part moved by an electric motor, the locking part is moved in the direction of the closed state thereof, until the same reaches a stop position. At that location the meter reading of a position meter describing the stop position is detected and buffered. Subsequently a movement of the locking part is carried out in the direction of the opened state thereof. The locking part is then moved again in the direction of the closed state thereof, until it again reaches a stop position. At that location a meter reading describing the stop position is detected, and compared to the buffered meter reading. If both meter readings agree, the first stop position is determined as the reference position. The method and device can be utilized, for example, for power window lifts and sunroofs of motor vehicles.

Abstract: A motor-drive circuit includes: an output transistor configured to supply a drive current to a motor for a cooling fan; a switching-control circuit configured to control switching of the output transistor so that the motor rotates in a first direction, or rotates in a second direction opposite to the first direction; and a switching circuit configured to, when a first time has elapsed since start of rotation of the motor in the first direction, cause the switching-control circuit to start switching control so that the motor stops rotating in the first direction and thereafter rotates in the second direction, and configured to, when a second time has elapsed since start of rotation of the motor in the second direction, cause the switching-control circuit to start switching control so that the motor stops rotating in the second direction and thereafter rotates in the first direction.

Abstract: In a closure panel control apparatus, an ECU controls a rotational speed of an electric motor, which provides a drive force to drive a closure panel in an opening movement and a closing movement thereof. The ECU obtains a vehicle speed measured with a vehicle speed sensor and receives a command signal from a switch, which is operable by an occupant of a vehicle to command the opening movement or the closing movement of the closure panel. The ECU controls the rotational speed of the electric motor based on the measured vehicle speed that is obtained at the time of receiving the command signal from the switch.

Abstract: A method for controlling an opening leaf of a vehicle. The method detects whether a predetermined event is occurring in the absence of a predetermined situation likenable to a trapping incident and, if appropriate, lowers a function of detecting the situation likenable to a trapping incident.

Abstract: The motor driving device includes a first function of supplying power to a motor so that the motor generates a driving force to drive a driven member, a second function of detecting a current flowing through the motor, a third function of performing a power supply control in order that a value of the current detected by the second function is maintained within a target range, a fourth function of performing a power supply operation in which the motor is supplied with power for a predetermined time period which is short enough to avoid the driven member from being driven by the motor, before the third function performs the power supply control, and a fifth function of making a judgment on a state of each of the first to third functions on the basis of the value of the current detected by the second function during the predetermined time period.

Abstract: An oscillating type piston is connected to an output shaft of an electric motor through a crankshaft. The piston is provided with a lip ring that slidingly contacts a cylinder. The motor is rotated forward and reversely by using a control circuit. Thus, different regions of the piston are subjected to a load during forward rotation of the motor and during reverse rotation thereof. Accordingly, wear of the lip ring can be distributed to different regions thereof.

Abstract: A motor driving device, which drives a DC motor, includes a motor driving unit, a status determination unit, and an initial value renewal unit. The motor driving unit repeatedly performs a change-over, wherein the motor driving unit changes an amount of a current inputted into the DC motor to an initial value at a predetermined timing, and then gradually increases the amount of the current from the initial value, in order to slowly move a driving target, driven by rotational force of the DC motor, in a moving direction. The status determination unit determines whether or not the driving target is in a predetermined status. The initial value renewal unit changes the initial value when the status determination unit determines that the driving target is in the predetermined status.

Abstract: A controller for controlling a sliding roof sets, as an operating area, a predetermined range in the sunroof slidable range and controls a motor driving the sliding roof such that the sliding roof slides in the operating area. When the sliding roof stops near a sliding lock end, the stop position is stored on an assumption that the positional deviation would occur. The sliding roof slides again from the stop position. Based on whether a traveling distance from the stop position to the sliding roof comes into contact with the tilt lock end is longer than the sunroof slidable range, the positional deviation is determined. It is possible to accurately determine whether the sliding member is locked and stopped by positional deviation or the intrusion of foreign object.

Abstract: The present invention relates to a fabric treating apparatus and method for controlling the same. A fabric treating apparatus according to the present invention includes a treating space within which fabrics are treated; a heating unit configured to supply heated air, or steam, or heated air and steam to the treating chamber; a motor to generate a rotational power; a device receiving the rotational power from the motor, the device configured to move a rack disposed within the treating space; and a control unit adapted to: control the motor according to a sensed electric current of the motor, and drive the motor to rotate at a speed defined by a target number of rotations per minute.

Abstract: A trash can can include a sensor for detecting the presence of an object near a lower portion of the trash can. The detection of the object can be used to signal the trash can to open its lid. The trash can can include an electric drive unit for opening and closing the lid.

Abstract: The present invention concerns a method for the position-dependent control of a mobile element in a motor vehicle, wherein the element is movable in a drive movement by an electrically powered positioning device, wherein the positioning device has several different operational modes, and characteristics of a drive signal of the positing device, in particular a waviness of a drive current, are used for the determination of the position of the element. According to the invention, a characteristic variable, which influences the drive movement of the positioning device, and/or a specific value, which characterizes the positioning device, are evaluated for the determination of an error value of the determined position of the mobile element, and that the operating modes of the positioning device are controlled in dependence of the determined error value.

Abstract: An apparatus is provided and includes a power source, a system board on which an electrical component is installed, a heat sink including a plurality of heat transfer surfaces to contact the electrical component and to thereby remove heat from the electrical component, a fan reversing control card coupled to the system board and configured to generate normal and reverse cycle rotation signals, and a fan coupled to the fan reversing control card and configured to receive the normal and reverse cycle rotation signals and to thereby operate in normal and reverse cycles in which the fan rotates in first and second directions, respectively, the fan being disposed within the computer such that the first and second directional rotations of the fan generate air flows in first and second directions with respect to the heat transfer surfaces, respectively.

Abstract: A method and apparatus to automatically reverse the motor of a power tool, such as a dispensing gun or similar tool. In some constructions, a controller automatically reverses the direction of plunger movement and removes the plunger from contact with the back wall of a cartridge. The controller has a trigger switch that is coupled to a power source, such as a battery, and includes a main power on/off switch and a potentiometer. A protection or secondary switch is coupled in parallel to the main power on/off switch. A power supply circuit and a commutator are each coupled to the main and secondary switches. An overload sensor is coupled to the commutator. The controller includes a programmable device that is coupled to the power supply circuit, the potentiometer, the commutator, and the overload sensor.

Abstract: An automated garage door closing device for a remote controlled overhead garage door wherein the device is mounted on one of a pair of parallel tracks receiving rollers suitably mounted on the outer edges of the door panels, the device including a switch housing containing a switch for the leading edge of the door, and a circuit located in a second housing adjacent the garage floor and including an interval timer acting to close the door after a predetermined period of time, an audible alarm which is activated upon the garage door reaching the fully open position, a switch deactivating the entire unit when the garage door is deliberately to be left in the fully open position, and a flexible switch arm extending through the switch housing to a position to engage the upper edge of the garage door panel and acts to activate the automated closing device.

Abstract: A container includes a fan that is reversible so air can be removed from the container as a flexible bag is placed into the container and ambient air can be forced into the container when the flexible bag is being removed from the container. This will facilitate placement and removal of a flexible bag in and from the container.

Abstract: A method and apparatus to automatically reverse the motor of a power tool, such as a dispensing gun or similar tool. In some constructions, a controller automatically reverses the direction of plunger movement and removes the plunger from contact with the back wall of a cartridge. The controller has a trigger switch that is coupled to a power source, such as a battery, and includes a main power on/off switch and a potentiometer. A protection or secondary switch is coupled in parallel to the main power on/off switch. A power supply circuit and a commutator are each coupled to the main and secondary switches. An overload sensor is coupled to the commutator. The controller includes a programmable device that is coupled to the power supply circuit, the potentiometer, the commutator, and the overload sensor.

Abstract: A method for determining a change in direction of rotation of a motor includes the steps of establishing steady state operating parameters of the motor, triggering a command interrupting the rotation of the motor, estimating the speed of the motor after triggering the command and determining the instant from which the speed of the motor is below zero. This instant corresponds to the change in direction of rotation of the motor. The instant from which the motor changes direction of rotation can be determined accurately.

Abstract: The power window system moves a window glass in opening and closing directions in response to operation of an opening and closing instruction switch. The power window system includes a measurement device for obtaining an open degree of the window glass and a control device for controlling movement of the window glass in response to operation of the switch. The control device moves the window glass in the closing direction when an open degree obtained by the measurement device is not less than a predetermined degree and in the opening direction when the open degree is less than the predetermined degree.

Abstract: Various embodiments of an electrical motor, a brushless DC motor controller, and applications thereof. In one embodiment, a fluid-moving device is provided with a brushless DC motor and a motor controller. The controller may include a set of comparators and a clocked digital circuit. The set of comparators are each configured to determine a voltage polarity on a respective winding of a stator. The clocked digital circuit is configured to receive polarity signals from the comparators and configured to detect in the polarity signals zero crossings having an expected crossing direction. The clocked digital circuit is also configured to determine a commutational sequence for energizing windings on the stator. Other embodiments may include a disk drive, an implantable medical device, a vehicle, and a downhole tool.

Abstract: A circuit configuration for driving an electric motor, in particular of a washing machine, includes power switches connected to connection terminals of the electric motor and to a voltage intermediate circuit. A driver circuit is connected to the voltage intermediate circuit and to the power switches. A control unit, in particular a micro controller, is connected to the driver circuit. The control unit generates control signals for controlling at least one rotation speed of the electric motor. The driver circuit generates short-circuit control signals for driving the power switches, which bring about a short circuit of the connection terminals connected to the power switches, independently of the control signals from the control unit. The driver circuit generates the short-circuit control signals as a function of a detection of an overvoltage of the voltage intermediate circuit over a desired voltage range. A method for controlling an electric motor is also provided.

Abstract: A hoist is powered by a separate power unit. The hoist unit includes: a motor, a mounting connector, a spool, webbing, auto cut-off and a first portion of a mating electrical connector. The control unit includes a hollow pole, a hook, a second portion of the mating electrical connector, a control switch, electrical circuitry and a battery pack.

Abstract: A motorized barrier operator system that moves a barrier between limit positions includes a barrier, a motor coupled to the barrier and adapted to move the barrier between a full open limit position, a danger zone position, and a full close position. The system further includes a position sensor coupled to one of the barrier and the motor to detect the positions, and a force sensor coupled to one of the barrier and the motor to detect an actual force value during movement of the barrier. A controller is connected to the sensors which determines a first threshold response value between the full open limit position and the danger zone position, and a second threshold response value between the danger zone position and the full close limit position. The second threshold response value is less than the first threshold response value, and the controller commands the motor to at least stop movement of the barrier if the actual force value is greater than either of the threshold response values.

Abstract: A method and apparatus to automatically reverse the motor of a power tool, such as a dispensing gun or similar tool. In some constructions, a controller automatically reverses the direction of plunger movement and removes the plunger from contact with the back wall of a cartridge. The controller has a trigger switch that is coupled to a power source, such as a battery, and includes a main power on/off switch and a potentiometer. A protection or secondary switch is coupled in parallel to the main power on/off switch. A power supply circuit and a commutator are each coupled to the main and secondary switches. An overload sensor is coupled to the commutator. The controller includes a programmable device that is coupled to the power supply circuit, the potentiometer, the commutator, and the overload sensor.

Abstract: An improved drive circuit is provided for a DC motor. The drive circuit includes: a DC power source; a relay having a normally open contact and a normally closed contact; a DC motor electrically connected through the normally open contact of the relay to the power source; and a discharge circuit connected in parallel to the DC motor. More specifically, the discharge circuit is coupled to the normally closed contact of the relay and operable to inhibit current flow from the DC motor until the relay has settled in a closed position.

Abstract: A drill/driver (e.g. an electric drill) with a screwdriver bit attachment, and a method of controlling the drill/driver, are described. This method of control will greatly reduce the occurrence of stripped screw heads on most types of screws. By periodically stopping insertion of a screw and reversing direction of the screwdriver bit, the screwdriver bit will be reinserted fully back into the screw head. By ensuring the screwdriver bit is always fully inserted in the screw head, the stripping of a screw head will be prevented. This can be easily implemented on most types of powered screwdrivers including the most common device used for screw insertion on a construction job site, the cordless drill/driver.

Abstract: The invention relates to a windshield wiper system with two wipers (1, 2) that travel in opposite directions and can each be driven by a separate motor (MFS, MBS), wherein a regulating unit (7) is provided for triggering the motors (MFS, MBS) separately from each other by means of control signals, wherein the regulating unit (7) triggers the motors (MFS, MBS) of the wipers (1, 2) in order to preset a time-dependent angular position of the wipers according to a trigonometric function ?(t).

Abstract: A field effect transistor is provided between the ground and an H bridge circuit for rotating a motor in forward and reverse directions in a manner that the drain of the transistor is grounded and the gate thereof is coupled to a DC power source such as a battery serving as a bias source which supplies electric power to the H bridge circuit. Thus, when the DC power source such as a battery is reversely connected, the field effect transistor normally in an on state is turned off. A controller monitors the source voltage of the field effect transistor, and when the controller detects an excess current, the controller outputs a control signal to the high-side driver to prevent the supply of electric power to the motor.

Abstract: In an electric motor-driven power steering apparatus which comprises a bridge circuit for connecting a power source between input terminals and also connecting an electric motor between output terminals and energizes the electric motor by this bridge circuit and operates electric motor power to a steering system, the bridge circuit includes a predetermined number of arms constructed by connecting circuits for connecting switching elements in parallel with diodes in series so that the diodes mutually become reverse polarity.