Abstract: A method for monitoring a motor unit is provided. The method includes: detecting a starting rotor position: ascertaining a non-safety-critical position tolerance range; ascertaining a position offset for the rotor as a function of the ascertained position tolerance range; ascertaining a target rotor position for the rotor based on the starting rotor position and the position offset; specifying a target control pattern based on the ascertained target rotor position; generating and applying a motor control pattern to the motor unit to rotate the rotor to the specified target rotor position using the target control pattern; detecting an actual control pattern controlling the motor unit at an interface between the motor controller and the motor unit; detecting an actual rotor position resulting from the rotation of the rotor using the motor control pattern; and feeding back both the detected actual control pattern and the detected actual rotor position for verification thereof.

Abstract: The pinch detector is suitable to detect a pinch at a closing member actuated by a motor equipped with a measuring circuit to measure a motor current. It includes a first portion that, when the motor starts closing the member, obtains a reference value of the motor current measured at the end of a blind time period having a predetermined duration from the moment the motor starts to close the member; a second portion that compares current values of the measured motor current to a threshold value depending on said reference value, during a detection time period, following the blind time period and preceding a steady state time period of the motor, in order to detect a pinch at the closing member based on a comparison result.

Abstract: A method of controlling a brushless motor that includes exciting a winding of the motor with a voltage, and freewheeling the winding when current in the winding exceeds a threshold or after the winding has been excited for a timeout period. The timeout period is adjusted in response to a change in one of the voltage and the motor speed. Additionally, a control system that implements the method, and a motor system that incorporates the control system.

Abstract: A method is specified for ascertaining an actuating position of a vehicle part that can be moved by an electric actuating motor. The speed of an actuating motor correlated therewith is acquired in a time-resolved manner during an actuation process. An initial no-load phase of the actuation process is identified, during which the actuating motor rotates while overcoming the system tolerance of the actuating mechanism without motion of the vehicle part. An actuating position measure for the actuating position of the vehicle part is ascertained from the motor rotation, with this measure being corrected during the no-load phase. By averaging over time, a test quantity is ascertained from the second derivative or the measured quantity correlating herewith. The end of the initial no-load phase is identified in this process when the test quantity exceeds a predetermined limit.

Abstract: Disclosed is a steering control apparatus having a structure by which it is possible to efficiently dissipate high heat that may be generated, simplify a manufacturing process, and reduce manufacturing costs.

Abstract: A switchgear includes a power supply built into a common housing, and at least two drives. The power supply can be fed by an external supply voltage and an external consumer can be connected to the two drives. In at least one embodiment, the switchgear includes, in the same housing, a built-in overload detection for the two drives and/or a built-in circuit breaker function for the two drives, and/or a built-in control circuit for the common control of the two drives. The switchgear can optionally be completed by a transformer providing an additional function of the targeted charging of a buffer capacitor and/or by an energy accumulator providing an additional function of the targeted discharge thereof by temporarily switching on a connected consumer.

Abstract: There are disclosed herein various implementations of a method and a system enabling operation of a motor in reverse. Such a method includes applying a first drive signal to begin rotating the motor in a reverse direction, the first drive signal being applied for a predetermined period of time. The method also includes using a position sensor signal for the motor to control motor drive in the reverse direction when the motor reaches a predetermined reverse speed, and operating the motor in the reverse direction.

Abstract: A driving apparatus includes an endless belt supported by a drive pulley configured to be driven by a motor and an idler pulley, and a moving member configured to be coupled to the endless belt and moved by driving the drive pulley by the motor, wherein a first limit value of electric power to be supplied to the motor when the moving member is moved in a first direction approaching the drive pulley is set larger than a second limit value of electric power to be supplied to the motor when the moving member is moved in a second direction approaching the idler pulley.

Abstract: A microcomputer 17 (signal generating section 24) includes an attenuating section 31, which attenuates a specific frequency component included in an input signal. The attenuating section 31 receives a d-axis current value Id and a q-axis current value Iq, which are actual currents supplied to a motor 12. The attenuating section 31 receives a rotational angular velocity ?e of the motor 12. The attenuating section 31 changes the specific frequency component to be attenuated based on the input rotational angular velocity ?e. Then, the microcomputer 17 executes current feedback control for feeding power to the motor 12 based on the d-axis current value Id? and the q-axis current value Iq? that have been attenuated.

Abstract: A motor driving circuit includes a control device, a detection module and a driving module. The control device is controlled by a control signal and is coupled to a motor. The control device includes a first terminal, a second terminal and a control terminal, wherein a driving current flowing through the motor flows through the first terminal and the second terminal. The detection module is used for detecting a voltage of the first terminal. The driving module is used for generating the control signal to control the driving current, wherein the detection module adjusts the driving capability of the driving module, thereby adjusting a slew rate of the control signal.

Abstract: A method for controlling a reversible polyphase rotating electrical machine, wherein at least one coil circuit is supplied through a bridge of switches, including the following steps: controlling (P1) the bridge to deliver to the coil circuit a periodic voltage with a phase shift (d) relative to an electromotive force induced in the coil circuit, such that an operating torque is generated, the phase shift having initially a first value (d0); controlling (P2) the bridge to deliver to the coil circuit a periodic voltage with the phase shift (d) producing a torque ranging between the operating torque and the opposite of the operating torque, the phase shift taking on a plurality of values upon the control; flipping (T2) the bridge in rectifying mode.

Abstract: The invention relates to a method and a circuit for regulating the speed of a commutator series-wound motor, especially a universal motor (10), which is supplied with a current from an a.c. voltage source (22) by means of a semiconductor switching element (18) mounted in series with an armature winding (12) and a field winding (14, 16) and controlled by a control unit (28) according to a nominal speed value. The control unit (28) receives, as input signals, signals corresponding to the total voltage drop (Umot) when the motor (10) is supplied with a current, and a substitute signal for the intensity of the motor current (I), corresponding to the voltage drop (Ua, Ufa) on the armature (12) alone or on the armature (12) and on a part (14) of the field winding (14, 16).

Abstract: The present invention is intended to, when rotation of a mirror rotation unit in a power-folding mirror is mechanically locked and its drive motor is thereby locked, make it possible to correctly detect this locked state. A motor 10 for a power-folding mirror is reversibly driven by an H-bridge drive circuit 12 formed of FETs 1 to 4. When the motor 10 is driven in normal rotation by turning the FETs 1 and 4 on and turning the FETs 2 and 3 off, the FET 1 is periodically turned off to detect a voltage of a terminal 10a of the motor 10 by means of a voltage detection circuit 14. When the FET 1 is turned off and the motor 10 is not locked, the motor 10 generates power by means of its inertial rotation, and when locked, the motor 10 generates no power, so the voltage detected by the voltage detection circuit 14 changes according to whether or not the motor 10 is locked. A CPU 20 determines whether or not the motor 10 is locked according to the voltage detected by the voltage detection circuit 14.

Abstract: An apparatus is used for controlling a rotating direction of a fan. The apparatus comprises a power source, a signaling unit, a switching unit, and an activating module. The power source is used for supplying power for the apparatus. The signaling unit is used for generating direction-control signals. The switching unit is connected to the power source and the signaling unit, and used for controlling the switching unit to work. The activating module is connected to the switching unit and the fan, and used for driving the fan to selectively rotate in one of two opposite directions based on the direction-control signals. A method for driving the fan in the two directions is also disclosed.

Abstract: A motor controller includes an inverter circuit, a speed detector, an amplifier, a voltage detector, and an offset voltage addition circuit. The inverter circuit drives a motor based on a PWM signal. The speed detector generates an actual speed signal corresponding to an actual speed of the motor. The amplifier outputs a differential voltage by amplifying a difference between the actual speed signal and a target speed signal. The voltage detector outputs a switch signal for switching rotation direction of the motor. The switch signal has a first level, when the differential voltage is equal to or greater than a predetermined value. The switch signal has a second level, when the differential voltage is less than the predetermined value. The offset voltage addition circuit adds an offset voltage to the differential voltage according to the signal level of the switch signal.

Abstract: During PWM control in which an actuator (9) is connected between the output terminals of a bridge circuit made up of switching elements (121, 122, 221, 222) and power is applied to the actuator (9) with signals G1U, G1L, G2U and G2L, driving timing signals are generated with a time interval (dead time) during which the switching elements (121, 122) and the switching elements (221, 222) are simultaneously turned off, and the actuator (9) is driven so as to have no overlapping dead time between a pair of half-bridge circuits, achieving response even with a differential input PWM signal (S51-S52) having a small time difference.

Abstract: A rotation information detection device detects rotation information of a DC motor based on a surge component waveform superimposed on a voltage waveform between the terminals of the DC motor or a current waveform of the DC motor, a circuit is provided which supplies a current of a current value Ipwm 45% during motor forward rotation or Ipwm 55% during reverse motor rotation to the motor over the period from when the motor starts braking operation to when it stops.

Abstract: Reversible motor including a stator having two windings (a–a?, b–b?), a start apparatus (c–c?) connected to one of the two windings (a–a?, b–b?) in series, switches (310,330,350) for providing power to the two windings selectively, wherein the switches, for reversing the motor, are connected selectively such that the direction of the current in the one of the two windings is reversed and the start apparatus is connected to the other one of the two windings in series, and a turns ratio and a cross section area ratio of the two windings being adjusted for a sufficient start torque and an optimal efficiency of the reversible motor.

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: An electric power steering removes external wiring connecting between an electric motor and a control unit, whereby the influence of radiation noise caused by a PWM operation can be reduced. In addition, the heat radiation and assemblability of the electric motor and the control unit can be improved, while achieving high power output. A housing 64 with a metal substrate 61 fixedly secured thereto is arranged at a side opposite to an electric motor 30. The cooling fins are formed on an outer side of a housing 64 and on an outer side and an inner side of a cover 65. A metal substrate 61, a large current substrate 62 and a control substrate 63 are arranged inside of the housing 64 and the cover 65 in a laminated structure.

Abstract: An electric power steering apparatus includes a steering torque detector, a brushless motor PWM-driven with a three-phase alternating motor current, a target current setting section for setting a d-axis target current value and a q-axis target current value, motor current detectors for detecting motor current values supplied to the brushless motor, a three-phase AC/d-q coordinate transformation circuit, a first deviation calculation circuit for calculating a deviation of a current value of a q-axis detection signal from the q-axis target current value, a second deviation calculation circuit for calculating a deviation of a direct current value a d-axis detection current signal from the d-axis target current, a motor control section for controlling driving of the brushless motor through a vector control process on the basis of deviation signals outputted from the first and second deviation calculation circuits, and an attenuation device provided in a feedback transmission path of the q-axis detection current s

Abstract: An electromotor can be selectively actuated for operation in both rotational directions. In the condition of the electromotor not energized with current, respectively one rotational direction of the electromotor is blocked and one rotational direction remains movable in a free-running manner. The circuit includes first and second diodes forward-connected from ground to first and second motor terminals, a respective change-over switch connecting each motor terminal selectively to power or ground, and a free-run blocking switch interposed preferably between one of the motor terminals and its associated change-over switch.

Abstract: A power window apparatus for a vehicle is comprised of an operation switch which includes a raising contact for outputting a window raising command when set at on-state and a lowering contact for outputting a window lowering command when set at on-state, and a controller which is arranged to execute a manual operation during a time period from a start moment at which the operation switch starts outputting one of the window raising and lowering commands to a first moment at which a first predetermined time period elapses from the start moment, to execute an automatic operation during a time period from the first moment to a second moment at which a second predetermined time period elapses from the start moment, and to execute the manual operation from the second moment.

Abstract: The invention relates to a circuit arrangement of an electromotor comprising two terminals, in which the electromotor can be actuated for operation for both rotational directions, and in which, in the condition of the electromotor not energized with current, respectively one rotational direction of the electromotor is blocked and one rotational direction remains movable.

Abstract: An AC motor is utilized to drive a closure on a vehicle. The use of the AC motor provides valuable benefits with regard to cost and size. Further, a three-phase AC motor may be utilized, and the pulses in its power supply monitored to determine an obstruction in the path of the closure. Frequency control may also be utilized to provide optimum control of the drive of the component at both start-up and stop.

Abstract: A control system for an electric vehicle, such as a golf car, that includes a plurality of power MOSFETs. The vehicle includes a shunt wound motor including an armature coil and a field coil. One of the MOSFETs is connected in parallel across the armature coil and another MOSFET is connected in series with the armature coil. The MOSFET across the armature coil includes a freewheel diode. When the motor is operating below its base speed, i.e., when the back EMF is below the power supply voltage, a current flow can be induced by momentarily turning on the series MOSFET, shorting the armature coil. Because of the residual inductance in the motor, a current flow in the counter clockwise direction is initiated at which point the series MOSFET is turned off. Consequently, a large voltage spike across the motor occurs which results in current flow back into the battery pack. By quickly turning the series MOSFET on and off the current flow can be maintained, and the regenerative braking can occur even at slow speeds.

Abstract: A control circuit for a direct-current motor driven in a clocked manner, includes an electrolytic capacitor connected in parallel and free-wheeling diode. Spurious radiation is reduced, in that a choke is connected between the positive motor supply voltage and the plus terminal of the electrolytic capacitor, and that the free-wheeling diode is disposed with its cathode between the choke and the electrolytic capacitor, and with its anode on the negative side of the d.c. motor.

Abstract: There is a method for controlling the movement of electrically operated assemblies, more particularly of window lifters, sliding roofs or the like in motor vehicles. The assembly has a setting device is connected to a drive device. At least in one partial area of the displacement path, the displacement force is restricted to a predetermined maximum value. A parameter is proportional to the displacement force of the electrically operated assembly. Upon reaching a boundary value corresponding to the maximum value of the displacement force over a predetermined time span, the parameter is regulated to a value corresponding to this boundary value.

Abstract: First FET power transistors of first power amplifying parts and second FET power transistors of second power amplifying parts form current paths from a DC power source to three-phase windings. Three-phase first amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the first power amplifying parts. Three-phase second amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the second power amplifying parts. A switching control part performs simultaneous on-off switching of the conduction control terminal sides of the first power amplifying parts, thereby causing first FET power transistors of the first power amplifying parts to perform high-frequency on-off switching. As a result, three-phase drive currents to the windings vary smoothly, thereby reducing motor vibration.

Abstract: A power output apparatus (20) of the present invention includes a clutch motor (30), an assist motor (40), and a controller (80) for controlling the clutch motor (30) and the assist motor (40). The clutch motor (30) includes an outer rotor (32) linked with a crankshaft (56) of a gasoline engine (50) and an inner rotor (34) connecting with a drive shaft (22). The assist motor (40) includes a rotor (42) connecting with the drive shaft (22). A control CPU (90) of the controller (80) controls a first driving circuit (91) to enable the clutch motor (30) to carry out the regenerative operation. The clutch motor (30) accordingly regenerates energy corresponding to a slip between the outer rotor (32) and the inner rotor (34) as electric power.

Abstract: A vehicle sliding door opening/closing control device includes a trouble detecting circuit for detecting a trouble in a control unit which is used for controlling operation of a motor to drive a vehicle sliding door in opening and closing direction, and switching unit responsive to detection of a trouble in the control unit by the trouble detecting circuit for shorting power input terminals of the motor, and after the lapse of a predetermined time, opening the power input terminals of the motor. Upon detection of the trouble in the control unit, the power input terminals of the motor are shorted so that the motor is kept in a locked state. In this instance, if the sliding door is moving at a high speed, it is possible to apply braking to the sliding door. Thereafter, after the lapse of the predetermined time, the switching unit opens the power input terminals of the motor to release a lock on the motor, thereby allowing the sliding door to be displaced by manual.

Abstract: A system for monitoring and controlling the opening and closing of an electrically driven device, such as a window or a sliding roof of an automobile, contains various mechanical components and is equipped with an electrical servo motor which can be controlled by operating elements and a sensor device which are connected to an electronic control unit that processes signals under safety aspects and to which a power semiconductor is connected. To minimize the forces exercised on any trapped object, the rating of the servo motor is controlled by the power semiconductor so that the regulating speed of a servotransmission of the device can be adjusted during its adjustment range in dependence on specified positions of the device.

Abstract: A switched reluctance motor is provided with a rotor position detecting apparatus for detecting a rotor position wherein the apparatus comprises a rotor position-sensing mechanism removably mounted in a ventilator hole formed in a side wall of a motor housing for enabling an easy replacement of printed circuit boards and photo-interrupters when they need to be repaired and maintained. The sensing mechanism includes a fixing member having spaced slots for receiving respective circuit boards.

Abstract: An adjustable speed control for use on a children's ride-on vehicle, where the speed control includes a switch assembly interposed between the battery and the motor of the vehicle. The switch assembly is selectively operable to connect the battery to the motor in one of a number of speed configurations, including a first speed configuration and a second speed configuration. An actuator is connected to the switch assembly and manipulable by a user to allow the user to operate the switch assembly to select a particular speed configuration from among the number of speed configurations. In one embodiment, a diode is disposed in series between the motor and battery in one of the speed configurations to provide a relatively current independent voltage drop between the motor and the battery. In an alternative embodiment, a childproof cover is disposed proximal to the actuator.

Abstract: An apparatus for controlling driving of a power window system having a motor drive current detection device for detecting a current flowing through the motor when the door glass is raised by the motor, a current variation calculation device for calculating a variation amount of the current detected by the motor drive current detection device, and a drive control device for stopping or reversing the motor when the variation-amount of the current exceeds a predetermined value and the gradient of the variation amount of the current is positive when the variation of the current starts. The apparatus can quickly and accurately judge whether an abnormal current is caused by noises or the squeeze of an alien substance, thereby eliminating unnecessary operations of the motor.

Abstract: There is disclosed a device for detecting an abnormality in relays which is adapted such that if there is a current flow through a motor (M) when first and second transistors (Q1, Q2) are off resulting from an abnormality such as melting of first and second motor driving relays (RL1, RL2), a controller (1) turns on the transistors (Q1, Q2) of a motor driving portion (2) in response to a detection signal from a signal detecting portion (3) and accordingly provides the same potential across the motor (M) to stop the motor (M) without a conventionally complicated, costly construction.

Abstract: A reversible electric device M is connected in an H bridge with a first side formed by first top and bottom switches and a second side formed by second top and bottom switches. The current Im flowing in the device from the first side to the second side is determined cyclically with a given constant switching frequency. The difference .DELTA. is determined between Im and an instantaneous set point current. Each cycle is divided with a ratio R into a first part and a second part. R is determined and for each part a set point setting for the switches (diagonal mode or freewheel mode) is chosen according to the sign .DELTA., the sign of the set point current (or of Im) and the value of a preselected correlation law relating to .DELTA. the mean value of the voltage that can be applied to the device during each cycle.

Abstract: An improved current sensing circuit is provided in, or for use with, a power delivery circuit having a current controlling device of the type which includes auxiliary current sensing terminals. The current sensing circuit is particularly useful in conjunction with a respective current sensing power MOSFET located in the "high side" of a switching circuit, such as an H-bridge switch for a bidirectional load. The current sensing circuit has two branches connected to the current sensing MOSFET and to a reference potential and constructed to provide an output voltage signal representative of the main current through the current sensing MOSFET. The first branch includes at least two transistors and a resistor serially connected between a current sense terminal of the MOSFET and a reference potential. The second branch also includes at least two serially connected transistors connected between a terminal of the MOSFET and the reference potential.

Abstract: A device for controlling a motor unit which displaces a screening unit which includes a power supply with at least one controlled electronic switch designed to feed a regulated electrical output to the motor unit and a control loop with a circuit which detects the difference between the value of the electrical output produced by the power supply and a reference value, and wherein the reference value is selected for the electrical output as a function of input signals received by the device.

Abstract: An improved current sensing circuit is provided in, or for use with, a power delivery circuit having a current controlling device of the type which includes auxiliary current sensing terminals. The current sensing circuit is particularly useful in conjunction with a respective current sensing power MOSFET located in the "high side" of a switching circuit, such as an H-bridge switch for a bidirectional load. The current sensing circuit has two branches connected to the current sensing MOSFET and to a reference potential and constructed to provide an output voltage signal representative of the main current through the current sensing MOSFET. The first branch includes at least two transistors and a resistor serially connected between a current sense terminal of the MOSFET and a reference potential. The second branch also includes at least two serially connected transistors connected between a terminal of the MOSFET and the reference potential.

Abstract: A load driving circuit includes a pair of push-pull circuits formed of bipolar transistors. A load is connected between the output terminals of the push-pull circuits and the polarity of a current flowing in the load can be changed to drive the load. The pair of push-pull circuits are controlled by means of an output transistor driving circuit. The output transistor driving circuit includes first and second driving transistors for driving output transistors constituting the push-pull circuits and first and second control transistors for preventing the flow of a through current. The emitter and collector of the first control transistor are respectively connected to the emitter and base of the first driving transistor or the emitter and base of the output transistor arranged on the power source side and constituting one push-pull circuit.

Abstract: An improved current sensing circuit is provided in, or for use with, a power delivery circuit having a current controlling device of the type which includes auxiliary current sensing terminals. The current sensing circuit is particularly useful in conjunction with a respective current sensing power MOSFET located in the "high side" of a switching circuit, such as an H-bridge switch for a bidirectional load. The current sensing circuit has two branches connected to the current sensing MOSFET and to a reference potential and constructed to provide an output voltage signal representative of the main current through the current sensing MOSFET. The first branch includes at least two transistors and a resistor serially connected between a current sense terminal of the MOSFET and a reference potential. The second branch also includes at least two serially connected transistors connected between a terminal of the MOSFET and the reference potential.

Abstract: A control circuit for connecting a load to a voltage source includes an electronic holding circuit having latched and unlatched states. When latched, the electronic holding circuit connects the load to the voltage source. A thermal device responsive to excessive current demand by the load automatically places the holding circuit in its unlatched state, and disconnects the load from the voltage source.

Abstract: A power window control circuit for a motor vehicle includes a FET and SCR in series across the power supply with their junction connected to one side of a motor armature, the other side of the motor armature being switchable between power supply terminals. To provide reverse battery protection, no anti-parallel diode is provided around the SCR. The activation circuit for the FET includes a capacitor bootstrap circuit controlled by a switching transistor and a zener diode from the drain to the gate. When conduction from the switch through the motor and SCR is stopped, the inductive energy from the armature windings dissipates through the internal anti-parallel diode of the FET. When opposite conduction from the FET through the motor and switch is stopped, the inductive energy causes the voltage across the FET to rise to the zener voltage and turn on the FET sufficiently to dissipate it.

Abstract: Current sensing of current through an "H" switch circuit is accomplished without the use of a dropping resistor. The current sensing is provided by using current sensing field effect transistors in conjunction with power field transistors.

Abstract: An MOS SCR and MOSFET "H" switch circuit for a DC motor is provided which allows for the use of a supply voltage of greater than 20 volts by clamping the gate-to-cathode voltage of the SCR's used therein to a predetermined value which is less than the gate-to-cathode breakdown voltage of said SCR's.

Abstract: The present invention discloses a technique to avoid catching a foreign object in a power window by detecting overload of the window drive motor and stopping or reversing the rotation of the motor in response to said detection. The reference value for detecting overload is updated in accordance with a actual load of the motor in each predetermined time interval .DELTA.T but, in the present invention, when the start of an increase of overload is detected, the beginning of time period .DELTA.T is started again from that time, and thereby detection of overload is always carried out within the shortest period. Moreover, a variety of check mechanisms are also provided for ensuring the fail-safe function of the apparatus and for enhancing reliability of the protective apparatus.

Abstract: A control system for reversing the rotation of a field wound motor is used in electric power steering systems. The system responds to control signals from a control means 25 to energize opposite legs of a bridge circuit 14 to direct current through the field winding 10 in the correct direction. At the same time the armature winding is energized. The control system provides a failure detection means 18 for the checking of the various control signals and the operation of the system to determine if there is any system failure to provide for a failsafe operation.

Abstract: A remote control circuit for a hard wired remote control controlling multiple functions in a multiple motor device has a reduced number of wires extending between the hand held control and the motor control circuit. The circuit includes a rectifier for generating a positive control voltage and a negative control voltage which are separately supplied along individual wires to the hand held control, and a single wire extending between the hand held control and the control circuit for each function, the voltage appearing along the wire designating the direction of movement of the function. A pair of parallel connected LEDs sense the polarity of the voltage and energize a triac corresponding to the polarity of the voltage appearing along the control wire to energize the proper winding of a reversible motor.

Abstract: A bi-directional driver system for an electrical load operable in response to two independent logic command signals provides a means for selecting the direction of current flow in the load when driven by the external command. A bridge circuit employs inputs to dual transistor switches operating in the saturated mode in series with the electrical load, cooperating with common emitter transistor linear amplifiers and diodes, and biased by the input logic signal so as to drive the load current in a predetermined direction. The circuit provides protection from undesired power supply current surges when logic command signals are applied to both inputs, and from transients due to failure of a saturated transistor switch at one input to cease conducting before the application of a command signal to the second input. Embodiments for inductive loads and annunciator lamps are described.