Abstract: An actuator control device used for, for instance, dampers of automobile air conditioners including first and second fixed contacts which are discontinuous on a path along which a movable contact travels and third and fourth fixed contacts which are also in a discontinuous fashion on the movable contact's path. A motor, that is, an actuator, is connected to a battery and rotated forward when the movable contact is in contact with the first contact and is rotated reversely when the movable contact is in contact with the third contact, thus opening and closing the damper. A first diode is connected to the second contact so that when the damper, which is rotated in a linkage with the movable contact, is opened and the movable contact comes into contact with the second contact, the first diode cuts off the current to the motor, thus completing the damper opening action.

Abstract: A motor drive circuit, in which a first transistor at a drive stage, a second transistor at an output stage to be driven by the first transistor and a third transistor downstream the output stage for a short braking operation are formed in a common substrate or a common well of the substrate, a region of either a P type or an N type in either the substrate or the well is connected with the first transistor via a conductor so that a parasitic transistor is formed in which the substrate or the well serves as its base, whereby a current flowing from the first transistor to the second transistor during the short braking operation is sinked by turning on the parasitic transistor.

Abstract: A method of operating bridge circuit for control of an inductive load is disclosed. The bridge circuit has a pair of input terminals for connection across a power source and a pair of output terminals for connection across the inductive load. Each arm of the bridge includes a transistor switch connecting an input terminal with an output terminal. Clamp circuits are connected to each pair of input and output terminals, taking inputs therefrom and responding to a transition through a predetermined voltage differential between the terminals for driving the transistor switch connecting the output terminal to the remaining input terminal, thereby limiting the output terminal to a predetermined voltage level.

Abstract: Provision of a digital controller in which the controller controls the bearing coil current by means of a switching bridge that periodically reverses the applied voltage to the coil. The controller selects an applied voltage from a plurality of discrete voltage sources. When a rapid change in the load current is required, a relatively large magnitude of applied voltage is used. When a relatively constant magnitude of average load current is required, a relatively smaller value of voltage is applied.

Abstract: A positioning control for linearly displacing an object (31) has a direct current motor (1) and a gear (2,21) for converting rotary into linear motion, a current supply (4) of current pulses having given frequency, amplitude and duration; a pole reverser; a rotatable operating element (51) coupled to an angular step generator (5) and a sensor of the sense of rotation. The pulse frequency of the current supply (4) is determined by the angular step generator (5) and the polarity of the pole changer is determined by the sensor of the sense of rotation. The characteristic curve of the speed of displacement of the object (31) as a function of the pulse frequency is kinked, in that for low pulse frequencies the speed increases proportionally slowly, and up from the level of a pulse frequency threshold, the speed increases markedly quicker. The invention is useful for microscope focussing drives.

Abstract: A spin motor assembly of a disk drive apparatus includes a stator having a plurality of wound coils associated therewith, and a rotor having a plurality of magnetic poles. Each winding structure of the stator is made up of two winding portions, with only one winding portion being used to drive the rotor relative to the stator upon drive current being applied to the winding structure, but with both winding portions being used to generate back electromotive force when drive current is cut off from the winding structure. This generated electromotive force is used to actuate an actuator motor to unload the read-write heads from the disk surface. As an alternative, each winding structure of the stator is made of a single winding, and the winding structures are used successively to drive the rotor relative to the stator, but with at least two winding portions generating back electromotive force when drive current is cut off.

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 dc motor switching circuit is disclosed, and the circuit includes: a forward revolution switching circuit section 1; a reverse revolution switching circuit section 2; a constant voltage section 3; a switching circuit section 4; an automatic circuit section 5; a manual circuit section 6; a resetting circuit section 7; and upper and lower limit detecting sections 8a, 8b. The dc motor switching circuit of the present invention can be applied to the power window switch of an automobile in a simple manner. Even in the case where upper and lower limits are set up as in a closing/opening device of a garage shutter, a universal application is possible. In all such cases, its constitution is simple, and the circuit is capable of preventing any undesirable result (such as degradation, burning and the like). Further, the automatic and manual operations can be carrier out in a convenient manner.

Abstract: The invention is a chopper control for electric cars. In the control device, the currents of the armatures A1 and A2 of electric car driving shunt motors connected to a power source L are controlled by first chopper devices CH1 and CH2, the currents, in the forward direction, the field coils SF1 and SF2 of the shunt motors are controlled by a second chopper device FCH1, and the currents, in the reverse direction, of the field coils are controlled by a third chopper coil FCH2.

Abstract: The servo amplifier is used for driving power transistors supplying current to a D.C. servo motor. The servo amplifier includes a control signal input; a tach signal input; circuitry coupled to the inputs for creating an error signal between the control signal and the tach signal; a triangular wave generator for generating a triangular wave form; a summing network for summing the error signal with the triangular wave; a modulator for modulating the resultanat signal; tri-state drive logic circuitry; and power transistor drive circuitry adapted to be coupled to the power transistors. The triangular wave modulator is coupled to the output of the summing network for supplying modulated signals to the tri-state drive logic circuitry and the drive logic circuitry having outputs coupled to the drive circuitry. The tri-state drive logic circuitry provides fast response to the error signals indicating a desired change in speed of the D.C. motor, and without over-shoot or hunting of the D.C. servo motor.

Abstract: In a method and a circuit for the monitoring of electromotive setting elements which are connected to a bridge output stage, the actual values of the currents in the branches of the bridge are compared with the desired values which apply to the corresponding state of switching. Depending on the result of the comparison and the state of switching of the bridge output stage, an error possibly present is read from a table. It should be emphasized, in particular, in this connection that with only one bridge circuit, two motors which are connected in parallel can be completely monitored.

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: 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: A normally non-conducting motor drive transistor is connected in parallel with a freewheeling diode. The transistor is briefly enabled while reverse recovery transition current is flowing in the freewheeling diode and thereby reduces noise created by the diode when it switches from conducting reverse recovery current to blocking reverse voltage.

Abstract: A novel electric, gear driven, frequency controlled oscillating device that oscillates a toy mouse or other toys to amuse, occupy, and entertain pets. Because this unit is gear driven, it provides enough torque to insure self restarting after being stopped by a playful cat. The device has a low profile, thereby making it difficult to tip over. The cat toy operates in a very low variable voltage range, 6 volts DC, for maximum safety. The device is battery operated and has no exposed wires for pets to chew on. Device may be mounted in virtually any plane for further variation.

Abstract: The bidirectional rotation device comprises a direct current motor connected in series with a capacitor and a reversible switching means. When a direct current voltage is applied to the series-connected combination of direct current motor and capacitor through the switching means in one position, the charged capacitor causes the motor to rotate in one direction for a short period of time; and when the voltage is again applied to the combination in the reversed polarities, the reversely charged capacitor will cause the motor to rotate in the reverse direction.

Abstract: An electric system for use in a motor vehicle. The system includes a battery mounted in the vehicle body; a controlling device mounted in the vehicle body and having first and second switches; and a positive/negative switching device mounted in the vehicle body and electrically connected to the battery and the controlling device. The switching device has an output member which includes first and second output parts. The switching device assumes, when the first switch of the controlling device is turned ON, a first condition wherein the first and second output parts are charged positive and negative respectively, and assumes, when the second switch of the controlling device is turned ON, a second condition wherein the first and second output parts are charged negative and positive respectively. First and second electric devices are mounted in the door and have an input member which includes first and second input parts.

Abstract: A magnetic bearing device that incorporates a magnetic movable member, a first supporting member having a first coil and a permanent magnet, a second supporting member having a second coil and a permanent magnet, state detecting means for detecting the displacement of the movable member, a first and second wirings for applying current, and switches connected to the first and second wirings for switching the direction of current applied to the first and second coils. The first and second supporting members are located so as to position the movable member between them. During operation, the movable member is magnetically supported so as not to be in contact with either of the supporting members. The first wiring has a first switch circuit connected to a first drive circuit, wherein the bottom end of the first coil is connected between the first switch circuit and the first drive circuit. The first and second wirings are connected in parallel between a dc power source and ground.

Abstract: A device for the electrical excitation of the coil or coils of an electromagnetic actuator, especially that of a linear motor, the coil of which has a low self-inductance. This coil is supplied by a bridge of transistors. The error between a reference voltage and a voltage proportional to the current in this coil is used to turn off a pair of transistors of the bridge, and simultaneously saturate a transistor of the other pair and make the other transistor work in linear mode. Two electronic switches and one sign discriminator are used to this end.

Abstract: A direct current powered, linear resonant cryocooler having a compressor in which the piston is reciprocated by a linear motor at substantially resonant frequency and the length of stroke of the piston is varied as a direct function of cryocooler temperature. There are two control loops, a temperature control loop and a voltage control loop which is independent of the temperature control loop. In the temperature control loop, temperature is sensed at the cryocooler or expander and the temperature signal is compared with a reference temperature signal to produce a temperature error signal or voltage. The voltage control loop controls motor voltage. As input to the voltage control loop, the linear motor voltage is fed back and compared with the temperature error voltage V.sub.TE to produce a voltage level signal V.sub.L in the input of the voltage control loop, representative of the correction required to obtain and then to maintain the cryocooler temperature represented by the reference temperature voltage.

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 bridge circuit (2) for driving a load such as an electric motor (36) in one direction or an opposite direction as desired, the circuit comprising first (4) and second (24) parallel arms for connection across an automobile battery supply voltage, each arm comprising an FET switch (6, 26) and a bipolar PNP transistor (8, 28) connected in series via mid-point nodes for connection across the load. In each arm the intrinsic diode of the field effect transistor and the base-emitter junction diode of the PNP transistor are arranged to conduct forward-biased current in opposite directions. In this way, no current path is provided through the arms of the bridge circuit in the event that the voltage supply to the circuit is reversed.

Abstract: A motor driving device for rotating a motor in forward and reverse directions which includes a switching circuit arranged in an H-bridge connection with both terminals of the motor, a controlling circuit, and an interception device provided on the respective terminal sides of the motor. The switching circuit includes two sets of switching transistors. The interception device protects the switching circuit by preventing both transistor sets from entering the ON-state at the same time, and thereby prevent the switching means from breaking down.

Abstract: An infrared remote control toy which needs a small amount of motor starting current includes a logic IC and a motor drive circuit consisting of four transistors connected in the form of a bridge, in which the bases of the third and fourth transistors are connected to the first and second junctions of the bridge.

Abstract: A tilt and trim operating mechanism for a marine outboard drive including a simplified electrical arrangement for operating a reversible electric motor from a DC power source. The circuitry includes four relay switches operated in such a manner as to simplify the cost of the components since four double contact relays can be employed rather than two, three contact relays.

Abstract: Motor control apparatus comprised of a drive circuit for supplying drive current to a motor, an overload detector coupled to the motor for detecting the magnitude of the motor current to produce an output signal if that current exceeds a predetermined threshold level caused by motor overload, and a control circuit coupled to the drive circuit and responsive to the output signal for controlling the drive current supplied to the motor, thereby controlling motor operation.

Abstract: A motor driving device is provided with switches connected with both terminals of a motor in an H-bridge connection and malfunction detectors connected with both terminals of said motor. The malfunction detectors are comprised of an impression part and a detection part which can detect the breakdown of the respective switches caused by open breakage or short breakage according to an output signal from the detection part corresponding to an input signal from the impression part.

Abstract: A multipurpose integrated circuit for driving in a switching mode an externally connected load or loads permits implementation of any appropriate supply scheme of the external load or loads through six output terminals thereof and is therefore useful in a large number of applications. The integrated circuit uses six integrated power switching devices provided with respective recirculation diodes and a single externally connected sensing resistor for generating, by means of a customary PWM control loop, a control signal by which means of a logic circuit configurable by progrmaming permits the generation of driving signals as a function of the control signal for all six integrated power switches in accordance with a configuration of the driving signals which conforms with the particular scheme of connection of the load or loads selected among the different bridge type and unipolar-motor type schemes which may be selected by programming.

Abstract: A fail-safe arrangement for an electrical power steering system is directed to providing a control arrangement for a power steering motor which will prevent abnormal operation from having adverse impact. The control system detects the welding or sticking together of closed relay contacs and functions to prevent such a situation by monitoring the motor terminal voltage so as to cut off power above a predetermined value regardless of position of the relay contacts.

Abstract: In accordance with the present invention, there is provided an electric reversing switch comprising an insulated base having an elongated cavity defined therein. An elongated insulation member is provided for oscillatory motion about an axis through the cavity through an angular interval between a first and second position. Conductive bridging elements are provided on the ends of the insulation member and biased outwardly from the insulation member along the axis thereof. A first pair comprising first and second fixed contacts is supported in the base, each including a contact portion within the cavity and being symmetrical disposed relative to the axis through the cavity.

Abstract: A logic-controlled circuit superimposes a constant voltage across an actuator or motor load that is driven by a bridge-type amplifier to control the constant velocity operation of such load in response to an applied logic signal that may also disable the bridge-type amplifier.

Abstract: A steering assembly for multiplying steering torque and motion applied from a steering wheel of a vehicle by fixed and selectively varying ratios, respectively. The applied steering torque and motion are coupled via an input shaft to a sun gear of a planetary gear set. Supplementary torque and steering motion are generated by a servo motor which is coupled to a ring gear of the planetary gear set via an irreversible differential planetary gear set. Rotational motion of the input shaft is determined and rotational motion of the servo motor is controlled as a selected function of the rotational motion of the input shaft. Actual rotational motion of the servo motor is measured and additional rotational motion of the servo motor is terminated if the actual rotational motion of the servo motor does not substantially match the selected rotational motion. A set of planetary gears mounted in a planetary carrier receives combined output torque and rotational motion from both the sun and ring gears.

Abstract: A circuit for signaling an operator when a linear actuator, driven by a reversible direct current motor, has reached opposite end positions. Two normally closed series-connected switches which open at the respective positions and diodes, connected across each switch and to each other in opposition, stop the motor when the actuator reaches either position. A third switch and third diode cause a lamp to energize at one of the positions and remain energized until the actuator moves to the other position.

Abstract: A motor is connected in series with a power supply through a reversing device for reversing the direction of rotation of the motor and a speed control circuit. The reversing device includes two switches normally in a standby position in which the supply circuit of the motor is open. A command device is capable of alternatively and temporarily switching the switches into an operating position, for starting the motor in the respective opposite directions of rotation, when it receives a signal to do so from detector elements which generate the signal only when they detect a condition of normal operation of the control device of the motor.

Abstract: A circuit in accordance with the invention has a complementary pair of a MISFET and a COMFET with their drains connected together. This allows fabrication on a single substrate for greater reliability and reduced cost. The circuit can be used in a full or one half "H-bridge" configuration for controlling current through a load such as a motor.

Abstract: The disclosure describes an impedance matching circuit for maintaining the input impedance, of a drive transistor as sensed by a driver circuit, substantially constant. The circuit is connected to the input of the drive transistor such that when the drive transistor is forward biased, the input impedance sensed by the drive circuit is the input impedance of the drive transistor, and when the drive transistor is reverse biased, the input impedance sensed by the driver circuit is the combination of the input impedance of the drive transistor and an impedance of the matching circuit.

Abstract: A DC motor is supplied, from a motor driver, with a brake voltage constituted by a forward drive voltage, a reverse drive voltage, and a stop voltage of a zero potential level. An operational current of the motor driver is supplied to a low-pass filter whose output is supplied to first and second sample and hold (S/H) circuits. The first S/H circuit performs its sampling operation after a minute period of time in which the brake voltage goes through a polarity inversion from the reverse drive voltage to the forward drive voltage. The second S/H circuit performs its sampling operation after a minute period of time in which the voltage applied is changed from the forward drive voltage to the reverse drive voltage. The outputs or sampled values of both S/H circuits are compared with each other by a comparator. When the sampled values equal each other, i.e., when the number of rotations of the motor becomes zero, the comparator outputs a coincidence pulse. This pulse is supplied to a stop detector.

Abstract: An interface circuit between a microcomputer and a MOSFET driver for motor control includes logic for failsafe motor control particularly to protect the driver. AND gates supply driver signals when a set of conditions are met. Certain conditions are mandated directly by the microcomputer. An analog oscillator and digital counter are used to time data signals from the microcomputer to assure continual computer operation. Other conditions are determined by the logic and include monitoring faulty motor current conditions, assuring that forward and reverse signals are not given concurrently, and assuring that there is a dead time between forward and reverse signals to the driver.

Abstract: An electric circuit with limit-switch for limiting rotatable range of an output shaft of an electric drive unit disposed between an electric motor and a control device for supplying a drive current thereto, comprising a first snap action limit switch disposed on a first input terminal of the motor, and a second snap action limit switch disposed on a second input terminal of the motor, the limit switches having pivot points of movable contacts on a motor side, their normally-closed contacts being connected to an output side of the control device and their normally-open contacts being connected to a common connecting point, and the normally-closed contacts of the first limit switch is connected to the common connecting point through a diode in the direction allowing an electric current to flow from each of the normally-closed contacts toward the common connecting point, and further comprising a diode for allowing an electric current to flow in parallel to the second limit switch, bypassing between the normally-

Abstract: A field installable motor operator for a circuit breaker includes a bidirectionally controllable motor that is coupled through a torque limited module to a circuit breaker operating mechanism. The motor is bidirectionally driven by a transistor switching bridge that supplies output current in reversible flow directions through one of the windings of the motor to the input of a rectifier bridge that supplies the other winding with currents that flow in the same direction. The torque limited module includes a centering and spacing ring which precisely confines the clutch elements to provide consistent torque. The motor is supplied with a current pulse of 250 milliseconds duration that is longer than the time required to fully operate the breaker. The clutch slips when breaker operation is completed and permits the motor to overrun without damage.

Abstract: A power window switch for an automobile having a switching mechanism which includes a fixed contact plate and a circuit board secured within the inside of a resinous casing, the casing including a port. Positioned above the port is a button which includes a sloped elastic portion having its outer edge secured to the casing around the port. Compression of the button's sloped elastic portion places a conductive rubber contact attached to the bottom surface of the button into contact with a fixed contact on the fixed contact plate. The circuit board includes a switching circuitry which is responsive to variations in position of the button and attached conductive rubber contact.

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: A signal amplifier including a bridge output stage, a comparator stage arranged to control a first part of the output stage in accordance with the polarity of an input signal, and a modulating stage arranged to control a second part of the output stage in accordance with the magnitude and polarity of the input signal. The signal amplifier is particularly suitable for fabrication as an integrated circuit.

Abstract: A circuit for sensing the magnitude and sense of a current flowing through the load of an H-bridge stage driving the load in a switching mode by means of a clocked, square-wave driving signal and the inverted signal thereof applied, respectively, to two pairs of analog switches arranged in a bridge configuration and functionally switching the load between a supply node and a virtual ground node is made by utilizing a single sensing resistance connected between the virtual ground node and the real ground node of the circuit, the signal across the resistance and the inverted signal thereof are fed to two inputs of an analog multiplex whose output signal is fed to the input of a comparator in order to obtain at the output of the latter a signal with an amplitude proportional to the intensity of the current and a polarity determined by the polarity of a reference voltage which is applied to another input of the comparator.

Abstract: A motor controlling switch device is disclosed which comprises a casing and an operating member provided in a casing which is movable from an original position and a first operating position and from the first operating position to a second operating position. A depressing piece is disposed in one of the casings and the operating member. Sloped surfaces and holding surfaces are formed in the casing and the operating member and coact with the depressing piece, respectively, for storing the operating member to the original position when the force on the operating member is released after it has moved to the first operating position and for holding the operating member in the second operating position when the operating member is moved through the first operating position. Forward and reverse rotation switches ae provided for establishing forward and reverse motor rotation circuits when the operating member is moved to the first and second operating positions for forward and reverse rotation.

Abstract: To control a reversible element (E), such as a motor and especially a motor operating a tape recorder tape transport, actual operating level input signals in form of timed pulses, depending on speed, and operating sign input signals are applied to a controller (8) through a frequency measuring circuit (5). The controller (8) compares the command level input signal and the actual input signal and provides corresponding error or control output signals. In accordance with the invention, a switch or gate (6) is interposed between the actual operating level input and a frequency measuring circuit (5) which, in turn, controls the controller, the gate or switch being conductive if and only if the sign of the actual operating signal and the sign of the command signal agree, as determined by an antivalence or AND-function gate (7). Upon disagreement of the sign signals, the gate is opened.

Abstract: A half-bridge driver circuit extends the duration of recirculating decaying currents in an inductance type indicating gauge after source voltage is cutoff. An inverter circuit controls a source transistor to provide a lower resistance path for the decay current than provided by the suppression diodes of the half-bridge driver.

Abstract: A method of and an arrangement for controlling the operation of a reversible D.C. electric motor including a winding having two ends each of which is connected to both the positive and negative terminals of an electric current source through respective control switches that can be selectively closed and opened in response to command signals to apply voltage differentials across the winding with attendant electric current flow through the winding in one or the opposite direction for operating the electric motor in one or the other of its senses of rotation with intervening rotation sense reversals utilize the original command signals for determining when the sense of rotation reversal would result in an excessive electric current flow through the winding.

Abstract: In a pocket size portable sound recorder, a special pushbutton swith is provided, and pulses are generated according to the number of operations of the pushbutton switch and are applied to a counter as upcount inputs. Also provided is a timer in which a pulse is generated whenever a specified time elapses after depression of the push button switch, and the pulse output is applied to the counter as a downcount input. Since the counter output is applied to the operation control circuit of the recorder, after the pushbutton switch is depressed, the recorder action will be carried out for a predetermined time period until the count value of the counter becomes zero. Also when the counter counts down to a predetermined value a flickering light is generated to indicate that the predetermined time is about to expire. If the special pushbutton is continuously depressed the counter is automatically reset to zero.

Abstract: A DC brush motor amplifier control includes a current switch power supply together with switching logic for operating the motor in response to a predetermined motor current signal. An encoder coupled to the DC brush motor provides a feedback signal used to control the motor operation. An overspeed detection system senses motor speeds in excess of a predetermined threshold and disables the switching logic to avoid overspeed failure.