Abstract: A large scale integrated circuit has a first circuit section with input terminals external of the integrated circuit connected to output terminals of a second portion of the integrated circuit for use in an environment not requiring intrinsic safety. When the circuit is to be installed in an environment requiring intrinsic safety the external connectors are disconnected from one another. An excess voltage suppression circuit is connected to the external connections of the second circuit section.

Abstract: An apparatus for driving an electric motor, including a full-wave rectifier which rectifies an alternating current supplied from an alternating-current power supply, and supplies a full-wave rectified current to the motor, a chopper which chops the full-wave rectified current supplied from the rectifier to the motor so that the chopped current is applied to the motor, and a control device which generates a chopping pulse signal having a first signal characteristic corresponding to a given motor control target and a second signal characteristic to reduce an alternating-current component of the full-wave rectified current supplied to the motor, the control device supplying the chopping pulse signal to the chopper so that the chopper chops the full-wave rectified current according to the chopping pulse signal.

Abstract: A bi-directionally actuated hand tool provides a power assist during loose forward and loose backward (low torque) operation. The subject tool can be used in conventional mechanisms such as a sleeving spanner, gear wrench, mobile wrench, screwdriver, hoist, power puller, or crane, using only a light torque auxiliary motor drive, power cells, and relevant operation switches to provide a power assist for the purpose of speeding-up low torque operations while permitting manually application of high torques. The operation switches of the auxiliary drive may be synchronized with the switch that normally controls tool direction, and the value of the torque output by the auxiliary motor drive can be limited by either a mechanical or electrical torque detector to cut-off automatically whenever the torque is exceeded.

Abstract: In a musical system, a transmitting device transmits performance data, a first receiving device is connectable to the transmitting device to receive and pass the performance data, and a second receiving device is connectable subsequently to the first receiving device to receive therefrom the performance data. The transmitting device operates to transmit first performance data arranged to drive a first sound source to generate musical tones and to transmit second performance data arranged to drive a second sound source of a type different than the first sound source. The first receiving device operates if the same has the first sound source for admitting the first performance data so as to drive the first sound source and for issuing a control message to the second receiving device. The second receiving device having the second sound source operates in response to the control message to prohibit admission of the second performance data to thereby disable the second sound source.

Abstract: A power feed system for feeding power to an electric vehicle includes a motor driving circuit provided with a smoothing capacitor. The motor driving circuit is capable of preventing the smoothing capacitor from being discharged and has a comparatively short main current supply line to reduce unnecessary power loss. The motor driving circuit converts dc supply power into ac supply power to feed the ac supply power to a motor. The motor driving circuit includes the smoothing capacitor and a plurality of semiconductor switching devices, which are built in the motor. An electromagnetic relay is placed within a case housing the motor driving circuit and the electromagnetic relay is controlled to supply a main current to the motor driving circuit and to interrupt the supply of the main current to the motor driving circuit.

Abstract: A method and apparatus for slowing back spin of a rod string of a progressing cavity pump powered by an electric motor when power is lost. Pulse direct current voltage into the windings of the electric motor powering the progressing cavity pump to magnetize a stator of the electric motor thereby reducing the rotational speed of a rotor of the electric motor and consequently the rotational speed of the back spinning rod string of the progressing cavity pump.

Abstract: A light beam, which scans in opposite directions across a bar code, is controlled in velocity and scan angle by monitoring the voltage across a winding of a motor, such as one of the phase windings of a two phase stepper motor, which causes the beam to scan across a field of view where the bar code is located. In order to enable the winding, which carries current for driving the motor, circuitry that inhibits the voltage from inductive generation (the back EMF) into the winding during periods when the drive current is applied to the motor. The drive current is applied in pulses, and preferably in groups of pulses, which groups recur periodically. In one embodiment of the invention, which utilizes a motor with two phase windings, the groups of pulses are applied alternately to different ones of the windings and the voltage due to inductive generation is derived from one of these windings during the time period where the pulses are applied to the other winding.

Abstract: The present invention provides a method for substantially eliminating backlash in drivetrain gears of a vehicle propelled by an electric motor. The method includes detecting whether brakes of the vehicle are applied. The method further comprises only if the brakes are applied, applying a torque from the electric motor to move at least some teeth of the gears into contact with one another. The present invention further provides a system for substantially eliminating backlash in a drivetrain of a motor vehicle. In one embodiment, the system comprises a plurality of wheels and a drivetrain coupled to at least one of said wheels and comprising engaging gears. The embodiment also includes brakes proximate to at least one of the wheels and adapted to selectively apply braking torque to the at least one of the wheels to which the brakes are proximate.

Abstract: In a d.c. brushless motor drive circuit, the output amplifier produces a motor winding drive current with dulled rise/fall edges from a detected sinusoidal back e.m.f. voltage induced on the winding during the steady-state operation when the motor runs at the rated speed. The output amplifier includes a set of transistors each brought to a saturated conductive state or a cutoff state in accordance with the phase conduction sequence to connect one end of each motor winding to a ground voltage source, and another transistor operated continuously to connect the neutral point, which is opposite ends of the motor windings connected together, to a power voltage source.

Abstract: A method and apparatus are disclosed for improving the efficiency of operation of AC induction motors. The method and apparatus utilizes a microprocessor to tune a motor control system such that the time interval between the turn-on of a bi-directional switch and the time of sensing the resultant inrush current through the stator is maintained substantially constant as the load is varied.

Abstract: An arm drive device for an industrial robot comprises a first arm rotatably supported on a supporting body, a second arm rotatably supported at the first arm and, a ball screw having a base portion adapted for rotatably supporting the end portion of a screw element which is rotatably supported at the supporting body. A nut portion is rotatably connected to a member for driving the first arm or the second arm, and a drive motor is provided for rotationally driving the ball screw. The drive motor is disposed at a position shifted but parallel to the center axis of ball screw, and the drive motor and ball screw are connected by a torque transmission means. Accordingly, resonance with frequency in the lower frequency region is prevented, thus making it possible to maintain a high level of locus accuracy of the robot arm.

Abstract: A system and method is disclosed for feedback velocity control of a D.C. motor. The system includes a motor (30) which is represented by its circuit equivalent--a series combination of an inductance (32), a resistor (34) and a back EMF source (36). The drive to the motor (30), supplied by a controller, is periodically inhibited by timing logic (22) and AND gate (20). Once the inductive transient decays via clamping diode (38) such that the motor current is zero, switch (40) is closed and the internally generated motor voltage is sampled by a capacitor (42). A/D converter (44) transforms the sampled value to a digital value and sends it to the controller. The controller compares it to a predetermined desired value then makes the necessary adjustments to the drive signal.

Abstract: An electrical circuit for controlling start windings in induction motors of various sizes or horsepowers providing a broad range of application. The circuit for controlling start winding switching measures the current through both the start and run windings of the motor allowing the use of a single solid state device in the circuit. This combined current develops a voltage across a resistor which is used to gate on the solid state device when the voltage exceeds a threshold level. By using the solid state device in combination with the special resistor, a motor start switch is formed which can be used to start a wide range of dual voltage motors.

Abstract: A micropositioner has a coarse positioner and a fine positioner, with a separate closed loop control circuit for the fine positioner. A disk head being positioned over a disk is attached to the stage of the fine positioner. The fine positioner includes a parallelogram flexure having first and second opposite sides attached respectively to the coarse positioning stage and the fine positioning stage. A piezoelectric translator translates the second side of the flexure relative to the coarse positioning stage. In order to sense displacement of the fine positioning stage relative to the coarse positioning stage, a differential electric field sensor is employed. The sensor includes a pair of side plates both mounted fixedly relative to one of the stages and opposing each other to create an electrical field between them, and a probe plate mounted fixedly relative to the other of the two stages and between the two side plates.

Abstract: In accordance with the present invention, an electric vehicle drive control system is provided. The system of the present invention controls the supply of actuating power to an electric motor for driving the vehicle. One preferred embodiment of the system permits a user to temporarily override a previously selected maximum power usage level for the motor so as to permit the amount of power supplied to the motor to be increased to a higher maximum power usage level.

Abstract: The present invention involves a control system for a motor having a main winding and an auxiliary winding disposed on a stator. A microprocessor determines the phase difference between the line voltage and the voltage between the main winding and the auxiliary winding to determine the rotational status of the rotor. In a moving rotor, a measurable phase difference exists. This phase difference can be measured by monitoring the zero crossings of the respective voltages. One method of measuring the phase difference is to check the logic state corresponding to the voltage between the main and auxiliary windings when a predetermined time period has elapsed after a zero crossing of the line voltage. Another method measures the time delay between the zero crossings of the two voltages. The control system of the present invention is particularly adapted for use with single phase AC motors having a main winding and an auxiliary winding disposed electrically out of phase on the stator.

Abstract: A gate operator with an extensible actuating arm adapted for light to moderate gate passing traffic. The operator comprises a small drive unit, such as an electric motor drive, and a rotatable drive shaft, such as a worm shaft driven through operation of the motor. An extensible shaft or so-called ball race shaft, cooperates with the rotatable shaft and extends inwardly or outwardly in response to rotation of the rotatable shaft. A microprocessor operated control circuit is used with or forms part of the operator, and measures a number of counts generated by magnetic elements rotatable with the worm shaft, and which are equivalent to distance units of measurement. In this way, the distance on the opening and closing movement is measured and stored in the microprocessor, so that on subsequent movements, the gate can open and close to precisely the open and closed positions without stopping short of or banging into such end positions.

Abstract: A dc motor wherein a driving force thereof can be used effectively with a simple and compact mechanical construction and a motor controlling system which can control such a dc motor to be driven efficiently. The motor comprises at least two coils, and change-over means for changing electric connection of the coils to change over the motor, when power is selectively supplied to the coils, between a first mode in which the torque produced is relatively high and the rotational frequency is relatively low and a second mode in which the torque is relatively low and the rotational frequency is relatively high. The motor controlling system includes selecting means for automatically selecting one of the first and second modes to control the change-over means in response to a given condition of the motor.

Abstract: An automated drafting system particularly suitable for drafting textile strands of sliver is provided. The automated drafting system includes a synchronous drive sliver drafting roller system utilizing toothed gears in the preferred embodiment operatively connecting a pair of drafting rollers with one of the rollers being directly driven by a motor to thereby cause identical rotation of both rollers. The automated drafting system also includes a system for securing and pressuring together upper and lower sliver drafting rollers wherein the lower roller of a pair of drafting rollers is preferably maintained in a fixed but rotational position while the upper roller of the pair is pressured towards the lower roller and controllably restricted as to both horizontal and vertical movement during the drafting process.

Abstract: Method and apparatus for accurately determining electromagnetic and mechanical information from electrodynamic rotary field machines, such as, for example, asynchronous, synchronous or reluctance machines that utilize voltage discontinuities generated by an associated inverter. The apparatus according to the present invention obtains information from machines running at a low rpm without using a mechanical transducer, as well as with machines running at a high rpm.