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 steering shaft locking device capable of performing a locking operation in an optimum manner. The steering shaft locking device includes a motor to which voltage is applied to generate a drive force. A locking bar is moved by the drive force of an actuator so as to engage the steering shaft. A steering shaft lock ECU connected to the motor performs a first control to move the locking bar to a lock position, at which the locking bar engages the steering shaft, and a second control to move the locking bar to an unlock position, at which the locking bar is disengaged from the steering shaft. A voltage control means controls the voltage applied to the motor during the first control such that the voltage is less than or equal to the voltage applied to the motor during the second control.

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: 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 motor driving circuit includes a window opening switch, a window closing switch, an auto switch, a motor which opens and closes a window by driving rotating operation, a charging circuit which charges one capacitance element by a first CR time constant upon operating the window opening switch, and a discharging circuit which sharply charges another capacitance element upon operating the auto switch and which discharges a discharging voltage charged to the other capacitance element by a second CR time constant upon stopping operation of the auto switch. Driving operation of the motor stops when a voltage of the one capacitance element in the charging circuit is higher than a first reference voltage or a voltage of the other capacitance element in the discharging circuit is lower than a second reference voltage during driving the motor.

Abstract: A three phase motor starting system is provided to reduce the in-rush current to the motor in order to obtain a soft start of the motor. The soft start of the motor equates to reduced impact forces on motor parts and device components connected to the motor during startup of the motor, especially a startup resulting from a reversal of the direction of rotation of the motor. The system uses an impedance load in series with the motor windings of the motor to reduce the in-rush current to the motor windings, which results in a reduced acceleration of the motor shaft and a soft start to the motor. The impedance loads used by the system can be a resistive load, a capacitive load or an inductive load, depending on the type of impedance load that is desired for the soft start of the motor.

Abstract: A children's ride-on vehicle having an electronic speed controller adapted to regulate at least one of the timing and rate of application of a selected rotational input. The vehicle includes a body with a seat, a steering mechanism positioned for operation by a child to steer at least one of the vehicle's wheels, and a drive assembly with an actuator positioned for actuation by a child sitting on the seat to cause the driven rotation of at least one of the vehicle's wheels by a battery-powered motor assembly. In some embodiments, the drive assembly includes one or more user input devices that enable a child sitting on the seat to select at least one of the relative speed and direction of the vehicle. The drive assembly also includes an electronic speed controller that controls electronically the transmission of a selected rotational input to the vehicle's driven wheel assembly.

Abstract: A method of operation for a motor-driven worm gear actuator coupled to a load device energizes the motor in a series of pulses during an initial period of motor operation when reversal of the motor is commanded. The pulsed energization produces a slow initial axial movement of the motor armature without moving the load device, minimizing the contact force between the armature shaft and a mechanical end stop of the motor. Rotation of the motor is determined by identifying and counting motor current pulses due to commutation, and the pulse count is adjusted at each reversal of motor rotation to compensate for motor current pulses due to the pulsed energization.

Abstract: A controller for a shutter moved between an opened position and a closed position. A plurality of location ranges is defined between the opened position and the closed position. The controller detects the current moving speed of the shutter in each range, compares the moving speed with a predetermined reference speed, and generates a stop signal based on the comparison result to stop the movement of the drive mechanism.

Abstract: A blender base that may be used with a food processor container, a blender container, and a single use beverage container. The blender container includes a novel blade unit having a food processor-style blade and blender type blades. Programs with preprogrammed motor commands for desired operations are stored in memory and may be selected by a user on a user interface. The user interface may include a liquid crystal display, or function switches and light emitting diodes. Upon selection of a particular pre-defined function, the microcontroller retrieves the appropriate program from the read only memory and specifies the preprogrammed motor commands to accomplish the selected function.

Abstract: A process for adjusting a motor vehicle part between at least two positions and a drive device for executing this process. The motor vehicle part is driven by an electric motor. A pulse signal is generated according to the rotary motion of the electric motor (10) and is supplied to a control unit (24) for controlling the electric motor (10). The instant of input of each signal on the control unit (24) is acquired and between two such input instants at certain extrapolation instants from at least some of these measured instants the current force acting on the motor vehicle part is estimated, this estimate being used as the criterion in the decision whether the electric motor (10) is turned off or reversed or not.

Abstract: A power window apparatus is provided that, even if a CPU (IC2) causes malfunction or becomes uncontrollable upon submergence, can prevent windows from performing unexpected operations and enables the windows to be opened without fail if desired.

Abstract: Method of detecting obstructions encountered by a motorized door. The method includes providing a signal processor with one or more signals indicative of a predetermined door trajectory profile for at least a segment of a stroke of the door, the door trajectory profile providing an ideal speed and/or position versus an elapsed time since a beginning of the segment of the stroke. A door position signal from a position encoder for the door is received into the signal processor. The method includes generating one or more signals indicative of the velocity and/or position of the door from the door position signal and generating a trajectory discrepancy signal based on the velocity and/or position in relation to the ideal speed and/or position. A motor control signal is generated based on the trajectory discrepancy signal and the motor control signal is connected to motor control circuits connected to drive the motor for the door.

Abstract: Method of controlling a motorized door by offloading the burden to a separate motion control processor. The method includes generating, in a central processor for the door, one or more signals indicative of a predetermined door speed profile for a stroke of the door. The predetermined door speed profile provides an ideal velocity versus an elapsed time since a beginning of the stroke. The signals are communicated to a motion control processor and the motion control processor also receives door position signals from a position encoder. The motion control processor generates signals indicative of the velocity of the door based on the door position signals and it generates error signals based on discrepancies between the velocity of the door and the ideal velocity. It generates motor control signals based on the error signals and the motor control signals are communicated to the motor of the door.

Abstract: A method for the electronic monitoring and control of the opening and closing operation of electrically operated aggregates, particularly of window lifters and sunroofs in motor vehicles, is described. A regulating unit of the aggregate is connected to a vehicle electrical system. The regulating unit is directly influenceable via electrical operating control elements, i.e., via a control-electronics interfacing circuitry connected to the aggregate. The control electronics interfacing circuitry is supplied with a signal that is a function of an accelerative force acting on a motor-vehicle body. The signal which is a function of the accelerative force, is determined from a motor speed of the regulating unit.

Abstract: A wiper control device suitable used for controlling the wiper apparatus possible to solve a difference in the wiping range caused by the difference in the operation speed (inertial force) of the wiper blade by using the wiper linkage provided with an eccentric mechanism and changing the rotational direction of a wiper motor according to the operation speed, the wiper control device is provided with a wiper switch, the wiper motor, a position switch, a controller and a motor driving circuit, and the controller executes control to change the rotational direction of the wiper motor at the time when the wiper blade arrives in the upper or lower turning position in response to switching operation of the wiper mode.

Abstract: Three phase sinusoidal waveforms generated from a DC bus voltage using Space Vector PWM method are used to obtain multi-speeds from a 3 Phase AC Induction motor. A novel algorithm generates the switching signals from a micro controller to drive the power devices of the Inverter Bridge, the output of which is applied to the motor. At different speeds, below the rated voltage of the motor, the output voltage V and the frequency f are maintained to keep V/f constant so that the motor torque is kept constant. At above the rated voltage of the motor, only the frequency is increased to obtain constant output from the motor at increased speeds.

Abstract: In an embodiment, an automatic cutting device specifically defines the automatic cutting device such that the clutch includes a transmission drive gear being driven by the motor and having a first saw-tooth gear, and a transmission follower gear for transmitting the drive force to the worm, the transmission follower gear having a second saw-tooth gear located at a position corresponding to the first saw-tooth gear, wherein one of the transmission drive gears or the transmission follower gear is axially moveable and urged in such a direction that the first saw-tooth gear and the second saw-tooth gear are brought into meshing engagement with each other.

Abstract: A system which takes direct action to reverse the rotation of the window driving motor includes an optical fiber conductor arranged inside a substantially prismatic profile forming loops at the points where said conductor enters and exits from a series of incisions formed at regular intervals in the lateral areas of said profile. The profile is fitted inside a covering in the frame of a door. The incisions comprise a mouth for insertion of the conductor through a passageway which ends in the cavity wherein the conductor is retained by an adhesive or the like. The optical fiber conductor may be arranged continuously over the entire length of the perimeter of the frame or over parts thereof.

Abstract: A control system for a device powered by an AC power source is presented. The control system includes a fixed controller adapted to be wall-mounted and powered by the AC power source. The fixed controller is also adapted to transmit control signals to the device. The control system further includes at least one movable controller adapted to be powered by a DC power source and transmit control signals to the device. In one embodiment, both movable controller and the fixed controller are adapted to transmit to the receiver via the same transmission medium, such as RF or infrared. The electronic device to be controlled may, for example, comprise a ceiling fan and associated light fixtures.

Abstract: A power window apparatus is provided for detecting pinching in accordance with the opened/closed position of the window and a state of rotation of a motor, the apparatus having a position sensor which detects a safety-control suspension region of the window and which is an accurate sensor. A spiral guide groove is formed in the inner surface of a housing opposite to a rotational plate which is rotated by an output shaft of a motor which opens/closes a window. A follower which is guided by the spiral guide groove is able to move along a straight guide groove provided for the rotational plate in the radial direction. Terminals in the form of conductive films are provided for a printed circuit board accommodated in the housing. When the rotational plate has been rotated, the follower is guided by the spiral guide groove so as to be moved in the straight guide groove. Thus, a slide member provided for the follower is brought into contact with the terminals so that the terminals are conducted with each other.

Abstract: A drapery actuator to open and close draperies and the like, comprising a housing and a drive pulley supported by the housing to engage a drapery cord. A motor is supported by the housing for reversibility rotating the drive pulley to move the drapery cord between a first extreme position and a second extreme position. A first electrical switch is operatively connected to the motor and a second electrical switch is also operatively connected to the motor. Switch actuator cooperate with the drive pulley such that the first electrical switch is actuated when said drive pulley moves the drapery cord to the first extreme position and the second electrical switch is actuated when the drive pulley is reversibly rotated by the motor to move the drapery cord to the second extreme position whereby when the drapery cord is in the first extreme position and the second extreme position the motor is deactivated and the drapery cord ceases moving.

Abstract: A device for controlling the tilt angle of window blind blades having a motor with an output shaft and a slip clutch coupling the output shaft to a tilt control mechanism. A receiver and demodulator receives a modulated infra red carrier signal modulated with a code and to demodulate the carrier to produce corresponding electrical pulses. A decoder is coupled to an output of the receiver and demodulator and when powered provides an output on one of several output lines depending upon the coding of pulses from the receiver and demodulator. A motor driver circuit has an input coupled to the decoder and an output coupled to the motor, is operative to drive the motor in either a forward or reverse direction depending upon the output from the decoder, and a decoupler decouples the motor from the wand upon reaching an extreme of tilting of the blade when the motor is still running.

Abstract: Drive device for closing parts in motor vehicles, especially sliding roofs, sliding/lifting roofs, and the like, with a drive motor, a sensor for determining the actual rpm of the drive motor and a clamping protection means for disengaging or for reversing the direction of rotation of the drive motor when the danger of clamping of the closing parts arises. The device has a speed controller which delivers an actuating signal which is a function of the deviation of the actual speed from a set speed of the drive motor. The drive device also includes an actuating means for varying the supply voltage delivered to the drive motor depending on the actuating signal of the speed controller, and an evaluation means which triggers the clamping protection means and which determines the existence of incipient clamping based on a signal which is dependent on the actuating signal of the speed controller.

Abstract: A three state switch detection circuit converts a three state input to a two-bit binary output readable by a micro-controller or other digital logic. The circuit utilized complementary NPN and PNP transistors having coupled emitters and coupled bases connected by a resistor. The collector of the PNP transistor is connected by a resistor to ground while a complementary resistor ties the collector of the NPN transistor to V.sub.BATT. Additional circuitry preferably converts the voltage output from the collectors to a suitable voltage level readable by the micro-controller or other digital logic device.

Abstract: A DC motor control circuit which contains a DC motor as a part of bridge resistance constituting a bridge circuit includes a first terminal connected to one end of the DC motor in the bridge circuit. A switching transistor is connected to the first terminal. A second terminal is connected to the other end of the DC motor. A switching control circuit detects an unbalanced condition of the bridge circuit via the second terminal and controls the switching period of the switching transistor so as to restore the bridge circuit to a predetermined unbalanced condition or balanced condition. A part of the bridge circuit, the switching transistor and the switching control circuit are integrated into an IC, thereby the number of terminals for the IC is reduced and a coil and an externally added capacitor both for smoothing are unnecessary.

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: Electronic control circuits for model railroading including a reversing motor control circuit. An on-board electronic state machine indicates one at a time of a predetermined series of states including forward, neutral and reverse, and is clocked to the next state responsive to an interrupt in the track power signal. The circuit further includes reset means for resetting the state machine directly to a neutral state responsive to an interruption of the track power signal of extended duration. The state machine can be remotely programmed to reset to any desired one of the series of states in response to a track power signal interrupt. The unique reset state is useful for receiving various remote control signals without driving the motor.

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: An electronic control system for model railroads incorporates a motor control unit, an electronic state generator that generates particular operating state signals and a remote control signal generator that multiplies the number of remote control effects that would be available from the remote control signals alone.

Abstract: A vehicle window regulating apparatus is designed to move a window glass in a door on the side of a passenger seat up and down by operations of a remote contol switch installed on the door on the side of a driver seat. A relay is provided on a power supply line for supplying electric power to a motor in the door on the passenger seat side. This relay and the remote control switch are connected by way of a signal line and is of a diameter smaller than that of the power supply line. With operations on the remote control switch, switching signals are supplied to the relay via the signal line, and the relay is thereby turned on and off so as to supply electric power to the motor via the power supply line, so that the window glass is moved upward or downward.

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 signal generator 16 is disclosed. The invention is adapted for use with industrial positioning systems and includes an integrating circuit 22 for integrating an input error signal to provide an output error signal and a limiting circuit 24, connected between the input and output of the integrating circuit 22 for limiting the output error signal. The output error signal is then used in a conventional manner to control a work piece or an implement. The integration of the low level input error signal rapidly increases the power delivered to the positioning system to overcome initial static friction. When the amplitude of the error signal indicates that the industrial apparatus is within a predetermined tolerance, the amplitude of output error signal decreases exponentially to diminish rapidly the power delivered to the positioning system. The apparatus will therefore be positioned within a given tolerance range.

Abstract: A mechanism which engages the pull-cord that opens and closes draperies, whereby the mechanism possesses a unique motor control for its automatic operation by a lamp timer (any of the commercially available clock actuated switches which are used in many households to automatically turn lamps ON and OFF at desired times). An alternate control system whereby the mechanism may be operated by a wireless remote control system in concert with the lamp timer. An adjustable means whereby the draperies may be opened and closed to any of two independently selectable positions within the means of the drapery rod. An easy to install mounting bracket with an easy to adjust tension means for driving engagement and hand-operation of the pull-cord.

Abstract: For the purpose of achieving an efficient and long-lived switching contact making on the basis of a structural design saving space and material, a reversing circuit for direction reversal in the case of direct current drives comprises four single-pole contactors which are arranged in a square and which are provided with coils 1 and with contact bridges 2 as well as four contact pieces 3 for connecting the outer terminals with fixed contacts formed by said contact pieces 3, the contact pieces 3 being arranged on one side of the coils in a square within one plane.

Abstract: There is disclosed a safety apparatus for a motor driven window that comprises an elongated sensing mechanism that extends substantially across the width of a window aperture and along that side of the window aperture toward which a closing, motor driven window moves. Such elongated sensing mechanism is comprised, at least in part, of a piezoelectric cable for generating electrical pulses upon an obstruction extending across the path of the closing window being pushed against the sensing mechanism by the closing window. Coupled to the motor driven window is an electric motor that is connected so as to be responsive to the electrical pulses generated by the piezoelectric cable for automatically reversing the direction of rotation of the electric motor.

Abstract: A circuit for controlling three modes of operation of a multiple terminal load using a single positive DC voltage 12, simple circuitry, two relays 26, 30 and a single input control line 17. The circuit senses a switch 16, or logic device generating three conditions: open circuit, connection to positive voltage or connection to ground. Three operating modes are effected while minimizing the number of wires needed to control the multiple terminal load.

Abstract: Apparatus for using an a.c. power supply to bidirectionally drive a d.c. motor includes a first silicon controlled rectifier (SCR) having a cathode connected to a terminal of the motor and an anode connected to a circuit common junction. A second SCR has an anode connected to the motor terminal and a cathode connected to the common junction. An amplifier circuit including a PNP transistor connected in a common base configuration is connected between the gate of the first SCR and the common junction for selectively enabling or disabling the first SCR. Separate means are provided for selectively applying a signal to the amplifier circuit or to the gate of the second SCR for enabling the rotation of the motor in a first or second direction.

Abstract: Signal apparatus including an assembly for producing a signal beam and another assembly for sweeping the beam in at least one zone of rotation. A control circuit connected to the sweeping assembly causes it to sweep the signal beam in periodically reversed motion at a substantially constant angular velocity across the zone of rotation between preselected endpoints thereof.

Abstract: A reversible electric motor is operatively arranged to drive an air circulating fan. Circuitry is provided to reverse the direction of rotation of electric motor periodically to provide alternating direction of air movement. Timing and reversal is provided by either a timing clock, a microprocessor, a thermal relay or a rotating disc which carries a pair of touch stops therein.

Abstract: A control circuit for a reversible D.C. window drive motor that allows for one touch operations of the motor to automatically lower the associated window to its full down position following a relatively short actuation of the control switch in the "DOWN" position. Subsequent actuation and release of the control switch will cause interruption and inhibit the automatic lowering of the window. Longer actuations of the control switch allows for direct movement control of the window in the downward direction. Stall current sensing and excessive time sensing provide protection to the motor and the drive circuitry.

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: A child's battery-powered riding toy includes a floorboard with two spring-biased switches that must be closed by the child operator to place the vehicle in self-powered motion and can only be reached simultaneously of the child operator is safely aboard. The battery power supply is capable of providing high or low voltage to the motor drive, but a reversing switch is connected between the battery power supply and the motor drive, and it must be in its "forward" position to receive the high battery voltage. In its "reverse" position, the reversing switch separately connects the motor drive to only the low battery voltage. The spring-biased switch connected directly to the reversing switch has a dynamic braking load connected to it to be placed across the motor drive when the reversing switch is in its "forward" condition and the latter spring-biased switch is allowed to be under the control of its biasing spring.

Abstract: A H-switch circuit is disclosed for rotationally driving a DC motor in a forward or reverse direction. The H-switch circuit comprises overcurrent-detecting circuits for four output transistors, which are respectively provided in order to detect the output transistor having an overcurrent, a circuit for generating an output signal upon detecting an overcurrent an integrating circuit controlled to be in a charge or discharge state according to the output signal representative of an overcurrent condition, and a circuit for turning off the output transistors when the integrating circuit is in the charge state and setting the integrating circuit to a discharge state. The charge and discharge operations of the integrating circuit are intermittently repeated until the overcurrent condition of the output transistor ends.

Abstract: For a sliding roof device (100) having a panel transfer mechanism (11, 12, 13b, 31, 33, 34, 7, 21) for moving a roof panel (2), which is adapted to open and close a roof opening (3a) of a roof (1), between a close position and an open position, a tilt-up mechanism (11, 12, 13a, 32, 33, 34, 7, 21) for moving the roof panel between the close position and a tilt-up position, and a reversible electric motor (51) for actuating the panel transfer mechanism and the tilt-up mechanism, there is provided a control circuit (50) including a first operation switch (58) for actuating the motor to thereby have the roof panel moved from the close position to the open position and the tilt-up position, and a second operation switch (57) for actuating the motor to thereby have the roof panel moved from the open position and the tilt-up position to the close position.

Abstract: A system is disclosed for energizing an electric motor for forward or reverse rotation, which motor operative to open or close a side window pane of a door or a sun roof panel of an automobile. The motor is energized for forward or reverse rotation in accordance with the status of a pressure sensitive switch which is mounted on a window frame to detect the presence of an object or hand and an operation of up/down command changeover switches. If the presence of an object is detected by the sensor during the forward rotation of the motor which is effective to close the window pane, a self-hold circuit is triggered or set, and the motor is energized for reverse rotation. The motor is deenergized at a given time interval after the sensor has ceased to detect the object. The motor remains at rest as long as the self-hold circuit is set. In certain embodiments, the self-hold circuit is reset when up command changeover switch is moved from its up position to its non-operative position.

Abstract: A control unit for operating the motor of a motor driven headlamp carrier mechanism includes oscillator circuitry for generating a series of pulses for energizing the motor, voltage responsive means for sensing a motor counter-EMF related voltage as an indication of motor rotation, output circuitry for interrupting motor energization when the voltage responsive circuitry senses motor stall, and start circuitry for energizing the motor independent of the oscillator circuitry for a period of time sufficient to produce motor counter-EMF. Such control permits sensing of the engagement of the headlamp carrier with fixed mechanical stops without the use of position or torque limit switches.

Abstract: A position control system for controlling a motor-driven mechanism capable of occupying a plurality of specified positions comprises a plurality of switches for specifying a position to be occupied by the mechanism and an encoder for generating a specified position signal representative of the specified position and a loading circuit for providing a present position signal representative of the position presently occupied by the mechanism. A read-only memory circuit uses the specified and present position signals to provide a control signal for controlling the motor to move the mechanism to a particular position and a comparison signal and a particular position signal indicative of that particular position. A position detector responsive to the position of the mechanism provides a detection signal representative of the particular position when the mechanism reaches it.