Abstract: A device includes at least one photoconductor configured for exhibiting an electrical resistance Rphoto dependent on an illumination of a light-sensitive region of the at least one photoconductor and at least one photoconductor readout circuit. The photoconductor readout circuit is configured for determining a differential voltage related to changes of the electrical resistance Rphoto of the photoconductor. The photoconductor readout circuit includes at least one bias voltage source configured for applying at least one periodically modulated bias voltage to the photoconductor such that the electric output changes its polarity at least once. The device further includes at least one electrical circuit configured to balance the differential voltage at a given illumination level.

Abstract: A semiconductor integrated circuit device includes a first voltage terminal, a second voltage terminal, an output terminal, a high-side MOSFET connected between the first voltage terminal and the output terminal, a low-side MOSFET connected between the output terminal and the second voltage terminal and having first and second gate electrodes, a drive circuit that complementally switches on and off the high-side MOSFET and low-side MOSFET, and a second gate electrode control circuit that generates a second gate control signal supplied to the second gate electrode of the low-side MOSFET. The second gate electrode control circuit has a voltage generating circuit that supplies a negative voltage negative in polarity relative to a voltage at the source of the low-side MOSFET, to the second gate electrode of the low-side MOSFET.

Abstract: A semiconductor integrated circuit device includes a first voltage terminal, a second voltage terminal, an output terminal, a high-side MOSFET connected between the first voltage terminal and the output terminal, a low-side MOSFET connected between the output terminal and the second voltage terminal and having first and second gate electrodes, a drive circuit that complementally switches on and off the high-side MOSFET and low-side MOSFET, and a second gate electrode control circuit that generates a second gate control signal supplied to the second gate electrode of the low-side MOSFET. The second gate electrode control circuit has a voltage generating circuit that supplies a negative voltage negative in polarity relative to a voltage at the source of the low-side MOSFET, to the second gate electrode of the low-side MOSFET.

Abstract: A driver circuit for driving a portion of a motor system is disclosed. The driver circuit may include a current reverse detector operable to detect a current direction associated with the portion of the motor system, an insulated gate bipolar transistor (“IGBT”) driver, and an IGBT. The IGBT driver may include: a first input coupled to an output of the current reverse detector and a second input coupled to an operation indication signal.

Abstract: A transistor circuit includes a transistor having a control electrode, a first current electrode, and a second current electrode. A turn off mode change circuit has a signal input that receives a series of pulses, an output coupled to the control electrode of the transistor, and a control input. The turn off mode change circuit has a fast turn off mode and a slow turn off mode. A turn off mode detection circuit is coupled between the first current electrode and the second current electrode. The turn off mode change circuit detects when a transition from the fast turn off mode to the slow turn off mode is desired and when a transition from the slow turn off mode to the fast transition mode may be performed.

Abstract: A semiconductor integrated circuit device includes a first voltage terminal, a second voltage terminal, an output terminal, a high-side MOSFET connected between the first voltage terminal and the output terminal, a low-side MOSFET connected between the output terminal and the second voltage terminal and having first and second gate electrodes, a drive circuit that complementally switches on and off the high-side MOSFET and low-side MOSFET, and a second gate electrode control circuit that generates a second gate control signal supplied to the second gate electrode of the low-side MOSFET. The second gate electrode control circuit has a voltage generating circuit that supplies a negative voltage negative in polarity relative to a voltage at the source of the low-side MOSFET, to the second gate electrode of the low-side MOSFET.

Abstract: A semiconductor integrated circuit device includes a first voltage terminal, a second voltage terminal, an output terminal, a high-side MOSFET connected between the first voltage terminal and the output terminal, a low-side MOSFET connected between the output terminal and the second voltage terminal and having first and second gate electrodes, a drive circuit that complementally switches on and off the high-side MOSFET and low-side MOSFET, and a second gate electrode control circuit that generates a second gate control signal supplied to the second gate electrode of the low-side MOSFET. The second gate electrode control circuit has a voltage generating circuit that supplies a negative voltage negative in polarity relative to a voltage at the source of the low-side MOSFET, to the second gate electrode of the low-side MOSFET.

Abstract: A drive transistor is connected to a resonant load in a low-side drive configuration. The voltage across the conduction terminals of the drive transistor is sensed and compared to an over-voltage threshold. An over-voltage signal is asserted in response to the comparison. The drive transistor is controlled by a PWM control signal in normal mode. In response to the assertion of the over-voltage signal, the drive transistor is forced to turn on (irrespective of the PWM control signal) to relieve the over-voltage condition. Operation of the circuit may be disabled or forced into soft start mode in response to the assertion of the over-voltage signal. Additionally, the pulse width of the PWM control signal may be reduced in response to the assertion of the over-voltage signal.

Abstract: A servomotor drive device has a first converter, a regenerative resistor circuit having a first switching element and a regenerative resistor, a first connection part configured to connect a second converter in parallel to the regenerative resistor circuit in an attachable and detachable manner, and a first control unit configured to control the on and off states of the first switching element. The second converter has a second switching unit and a second control unit configured to return regenerative energy to an AC power source side by bringing the second switching element into the on state when the second converter is connected to the first connection part.

Abstract: This invention relates to a servo system for operating an exoskeleton adapted to encircle an object of interest and for supplying a force thereon. A servomotor is coupled to a power source and operates the position of the exoskeleton and thus the force exerted by the exoskeleton on the object of interest. A measuring unit measures a raw driving current signal Iraw supplied by the power source to drive the servomotor. A low pass filter applies a low pass frequency filtering on the measured a filtered current signal Ifiltered. A processing unit determines an actuated current signal Iactuated based on the servomotor setting parameters, where Iactuated indicates the contribution to Iraw from the servomotor when operating the position of the exoskeleton. The processing unit also determines a driving force current signal Iforce indicating the force exerted by the exoskeleton on the object of interest, where Iforce is proportional to the difference between Ifiltered and Iactuated.

Abstract: A servomotor drive device has a first converter, a regenerative resistor circuit having a first switching element and a regenerative resistor, a first connection part configured to connect a second converter in parallel to the regenerative resistor circuit in an attachable and detachable manner, and a first control unit configured to control the on and off states of the first switching element. The second converter has a second switching unit and a second control unit configured to return regenerative energy to an AC power source side by bringing the second switching element into the on state when the second converter is connected to the first connection part.

Abstract: One embodiment includes an apparatus comprising a closed loop feedback controller and a power output stage to couple to the closed loop feedback controller. The closed loop feedback controller and the power output stage are combined to form a single element.

Abstract: A system and method for generating commands for current subject to dynamic determinations of a limit. In one embodiment, the dynamically determined limit is a function of power dissipation in a component estimated from a measured current level and as a function of a measured temperature proximate to the component. In another embodiment, the limit is a lesser of two dynamically determined current levels. The system and method may be of particular use in a motor having limits determined with respect to a transistor and a motor winding. More particularly, estimated temperatures are established for a transistor and a motor winding for use in dynamically determining limits. Dynamic current limiting may be applied to a left and right wheeled vehicle such that the limit applied to both wheels is the lower of the limits dynamically determined for each wheel.

Abstract: For applying a driving current to a motor, an H-bridge circuit is constructed by a first and a second switching unit and a first and a second linear unit. An error amplifier generates an error signal representative of a difference between the driving current detected by a current detecting circuit and a command current signal. A state control circuit synchronously controls the first and second switching units and a feedback circuit. Through the feedback circuit, the error signal is selectively applied to the first or second linear unit such that one is operated in a linear mode and the other is operated in a nonconductive mode, thereby controlling the driving current to become proportional to the command current signal. The state control circuit further controls a brake circuit for transforming the error signal into a brake signal to operate the first and second linear units simultaneously in a conductive mode.

Abstract: A branch amplifier card for a nuclear reactor control rod drive control system is provided. The control system includes a control processor, a plurality of transponder cards arranged in clusters with each cluster under the control of a branch amplifier card. The branch amplifier card is configured to receive commands from the control processor, send the converted commands to transponder cards under the control of the branch amplifier card and to a downstream branch amplifier card, receive an acknowledge word from transponder cards under the control of the branch amplifier card, add AC voltage threshold level information about the transponder cards under the control of the branch amplifier card to the acknowledge word, permit transponder trouble information attached to the acknowledge word to remain in the acknowledge word, and resend the acknowledge word including the transponder trouble information to an upstream branch amplifier card.

Abstract: A deviation comparator (10) compares an output signal of a deviation detector (6) with a set limit value to anticipates a runaway, and if the runaway is judged thereby, an object unit (12) is isolated by a switch circuit (11), thereby to prevent destruction of a driving amplifier (9) and the object unit (12).

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 proportional control circuit for the direction and precise speed control of D.C. electric motors such as those used to drive camera tilt/pan mountings. The circuit applies current to D.C. motors in a push/pull proportional scheme whereby slewing speed is smoothly and precisely controlled and electromotive force provides motor braking. A single current source powers the motors through an "H" bridge switching amplifier arrangement responsive to the balance between two voltage dividers, one of which includes a controlling potentiometer that regulates both direction and speed.

Abstract: An isolator for connection between an informational signal source and a high voltage controlled load may be used with numerous combinations of different input signal type and magnitude and output signal requirements. The compensation for input and output signal variation is accomplished by changing a minimum number of easily accessible plug-in passive circuit components.

Abstract: A servo motor control system for accurately pointing and controlling the speed of a servo motor using a low resolution PWM signal. A PWM command value given in each control operation cycle for driving other servo motors is divided, and output to a power control device operating signal generation circuit.

Abstract: A load control system (10) generates a periodic failsafe signal (CO) and two control signals. The failsafe signal (CO) is used to drive a charge (20) pump which acts as a voltage multiplier to generate an enable signal. A DC bridge circuit (30) includes four n-channel MOSFETs (Q1-Q4), and the load control signals are used to close respective diagonally opposed pairs of the MOSFETs to apply voltage to a load. The load control signals also isolate selected switch drivers (K1-K4) from a power supply in order to prevent shorting of the bridge (30). The enable signal generated by the charge pump (20) is applied to two of the MOSFETs, and voltages are selected such that the MOSFETs will not close unless the enable signal is at a sufficiently high level to indicate proper oscillation of the failsafe signal (CO).

Abstract: A circuit is disclosed which provides power isolation between the initializing and driven circuit, allowing the logic of a wide pulse width signal to be effectively transmitted across pulse transformers and faithfully reproduced.

Abstract: An amplifier system for energizing a d.c. motor from a power source in response to an error signal includes a bridge circuit including a first switching transistor pair for supplying a first current from the power source through the motor in one direction and a second switching transistor pair for supplying a second current from the power source through the motor in the opposite direction. A zero crossing detector determines the sign of the error signal and enables the first transistor pair when the error is positive and enables the second transistor pair when the error is negative. A current sensing resistor senses the first and second currents through the motor and provides a motor current signal representative thereof. An absolute value circuit provides an absolute value error signal representative of the magnitude of the error signal.

Abstract: A power MOSFET reversing H-drive system having a first pair of N-channel and P-channel MOSFETs (Q1,Q2) connected in series with a load (LD1,LD2) to a power supply source (T1) and a second like pair of N-channel and P-channel MOSFETs (Q3,Q4) connected in series with the load (LD1,LD2) to the source (T1), each pair having a resistance voltage divider (R1-R2, R5-R6) for providing the P-channel MOSFET (Q1,Q3) with a different voltage level gate signal from the logic level input signal by which the N-channel MOSFET (Q2,Q4) is gated, an overvoltage protector (Z1,Z2) allowing extension of the supply voltage (T1) range under which the system is operable, and the on-state resistances and the flyback current capability of the intrinsic diodes (ID1-ID4) being matched to the size of the load to be driven.

Abstract: A servo system which generates a position error signal (PES) provides for periodically calibrating the magnitude of the PES to increase or decrease its magnitude as required by modifying the gain of a variable gain amplifier in the servo loop.

Abstract: By using the fly-wheel current effectively, the d.c. servo motor current can be rapidly decreased when the circuit becomes non-driving state or the driving polarity is changed, and the inexpensive circuit of the high performance driving circuit, in which the form factor of the driving signal is improved, can be obtained.

Abstract: A circuit for controlling the position of a driven member is disclosed which includes a control circuit for controlling the application of electrical power to a motor and a circuit element operable for generating position error signals corresponding to the position of the load which may in one embodiment constitute a rotor element of the motor. A comparator section is provided for comparing the position error signals with position reference signals and for generating control signals to effect rotation of the load in a desired direction. In one embodiment, the error signal is generated by a feedback loop including a potentiometer having a movable element coupled to the load or motor rotor, wherein the voltage magnitude of the error signal is varied in accordance with the rotational position of the load or rotor element. In a preferred embodiment, the comparator section includes first and second comparators respectively responsive to position deviations of the rotor in first and second rotational directions.

Abstract: Controller for an antenna rotator having a rotatable member on which is mounted an antenna to be rotated to various headings. Switching circuitry selectively energizes a motor in the rotator to rotate the member in either of two, opposite directions. Antenna headings are user selectable and pre-programmable, the controller including control circuitry for accepting pre-programmed headings entered from a keyboard, storing the pre-programmed headings and retrieving headings. Users can select a pre-programmed heading or enter a new heading via the keyboard, the control circuitry controlling the motor switching circuitry to rotate the antenna to the selected heading. Circuitry is also provided to energize a brake solenoid in the rotator to, in the absence of jamming or binding, release the brake.

Abstract: A motor-driven rotary actuator includes an electric drive motor adapted to be configured for providing one of a plurality of output torques and power transmission means including a rotatable output shaft. The transmission means is coupled to the drive motor and includes drive elements adapted to be formed of disparate materials selected for transmitting one of the output torques. An electric controller is coupled to the motor for providing rotation positioning control of the actuator output shaft in response to analog command signals.

Abstract: In a control circuit, which has a current switching-over circuit including at least four switching transistors for controlling a current flowing through an electromagnetic device, the control circuit has driving circuits each of which drives the switching transistors in such a way that a short circuit does not occur during the switching-over operation thereof.

Abstract: A driving circuit for use in controlling a motor for controlling an air mixing door, an inner and surrounding air change-over door and a mode setting door and the like used in a vehicle air conditioning device, or a motor used in opening or closing of window panes of a vehicle or in opening or closing the door which includes a control transistor for use in controlling a transistor circuit having a transistor to cause both normal and reverse directed currents to flow in a vehicle motor, the control transistor being operated until a specified period of time has elapsed after the power supply switch is turned on, the motor input being shut off by the control transistor so as to prevent erroneous operation of the motor just after the power supply switch is turned on or to prevent the production of a chattering sound caused by the operation of gear trains with the motor.

Abstract: Disclosed is an industrial robot having a function for controlling a current of a motor for driving, which comprises a circuit (41) for summing a plurality of input signals to which input signals of speed command, speed feedback, current command and current feedback are supplied, a switching circuit (23) for selectively switching the input of speed command to the inputs of current command and current feedback by a switching command signal and an operational amplifier (38) to which the switched signal is supplied. In this industrial robot, the position control is switched over to the current control by a switching command signal from a robot control device (22), and by the position control, an article to be held is shifted to a predetermined position and by the current control, driving electric motors (Mr, M.theta.

Abstract: A motor control device includes first and second pairs of transistors each connected to a power source, the first pair of transistors being adapted for connection to the terminals of the motor and capable of operating to connect the motor to the power source so that the motor is driven in a forward direction when the first pair of transistors conduct, the second pair of transistors being adapted for connection to the terminals of the motor and capable of operating to reversibly connect the motor to the power source so that the motor is driven in a reverse direction when the second pair of transistors conduct, first and second input terminals capable of receiving as input a signal for controlling the motor, a first element connected to the first input terminal and responsive to said signal to cause the first pair of transistors to conduct, the first element including a device responsive to said signal to prevent conduction of the second pair of transistors, a second element connected to the second input termin

Abstract: A power source for a pair of solenoid coils selectively acting in opposite directions on a single armature. The source includes a selectively variable D.C. power source selectively energizing either coil with opposite magnetic polarity and a dither signal generator which continuously supplies out of phase dither signals to the two coils.

Abstract: An inverter (34) which provides power to an A. C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A. C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A. C. machine is optimized. The control circuit includes a microcomputer and memory element which receive various parametric inputs and calculate optimized machine control data signals therefrom. The control data is asynchronously loaded into the inverter through an intermediate buffer (38). A base drive and overlap protection circuit is included to insure that both transistors of a complimentary pair are not conducting at the same time.

Abstract: A linear solid state servo amplifier operated from a low voltage source and which develops a voltage across the servo motor equal to the source voltage diminished only by the saturation voltages of two of its output transistors has a bridge output stage of complementary transistors and a bridge driver stage of complementary Darlington transistors having as its load a preselected resistor.

Abstract: A control circuit is disclosed for operating a pulse motor which contains a first winding and a second winding. A first bridge can connect the first winding to a power source in two directions and can also disconnect the first winding therefrom. Likewise, a second bridge can so connect and disconnect the second winding from the power source. A sequencer operates the bridges so that such connection and disconnection takes place according to a predetermined sequence, in order to allow the motor to be rotated in discrete steps. A comparator stage compares current flowing through the first and second windings with an adjustable voltage reference, and regulates the bridges so as to regulate such current in accordance with a value to which the adjustable voltage reference has been adjusted. A means adjusts the adjustable voltage reference in accordance with the predetermined sequence.

Abstract: Precision incremental-output integrator of the type comprising: an operational amplifier mounted as analog summing integrator, which sums currents I.sub.1 and I.sub.2 at the integrator input, characterized by the fact that current I.sub.2 is obtained by the discharge of a capacitor C.sub.2 and that the symmetrical reference voltage generator (Vr-), (Vr+) is replaced by a simple voltage generator (Vr) and incremental-output servosensors resulting from utilization of the said precision incremental-output integrator in which the measured magnitude, originally electrical, becomes a physical magnitude, evidenced by an electromechanical force generator by the fact that the analog amplifier of the precision incremental-output integrator (terminals A-S, FIG. 2) is replaced by the force generator of the servosensor (FIG. 3), the return current of which is current I.sub.2 discharged from capacitor C.sub.2.

Abstract: The switching amplifiers of the prior art improved by a variable hysteresis in the comparator circuitry of said amplifier. Said variable hysteresis is controlled by the power supply voltage and a frequency sensitive feedback circuit. If the amplifier load creates an excessive frequency which cannot be controlled, a fault detector circuit disables the amplifier.

Abstract: A photoelectric transducer (14) produces first and second periodic signals (A), (B) which are 90.degree. out of phase with each other in response to rotation of a servo motor shaft (12a). The first and second signals (A), (B) are differentiated, directly full wave rectified and summed to produce a velocity signal (Vw-) having a magnitude proportional to the rotational velocity of the shaft (12a). The peaks of the first and second signals (A), (B) are detected to produce a reference signal (Vr) having a magnitude corresponding thereto. The magnitude of the reference signal (Vr) is reduced in accordance with the difference between the present position of the shaft (12a) and a command position to produce a velocity command signal (Vc+). The velocity signal (Vw-) is compared with the velocity command signal (Vc+), to produce a drive signal corresponding to the difference therebetween which is applied to the motor (12). Fluctuations in the amplitude, D. C.

Abstract: A device for the remote control of the angular position of an aerial rotor comprising a d.c. motor for the rotation of the rotor and a drive circuit adapted to cause the rotation of the motor in one direction when it receives as input a d.c. voltage higher than a reference value and in the opposite direction when it receives as input a d.c. voltage lower than the reference value. The device provides for a feeder, in proximity of the receiver, for generating at least one d.c. control voltage and comprising a regulator of the value of the voltage as a function of the desired angular position of the rotor of the aerial, and a regulator and stabilizor of the d.c. control voltage, located in proximity of the drive circuit of the motor, to obtain from the d.c. control voltage a stabilized constant voltage of a value lower than the minimum value of the d.c. control voltage, for the feeding of the drive circuit and the motor.

Abstract: A power driver control circuit (38) provides control signals (44, 46, 48, 50, 52, 54) for switching transistors in a power driver (56) for an electromagnetic actuator (11) of the type used for controlling a servo head (12) in a closed loop servo system. The control circuit includes variable time delay circuits (70, 71) connected to threshold detectors (74, 84) so that dead zones can be created when the servo error signal changes polarity thereby isolating the switches and preventing switch burn-out.

Abstract: A power amplifier is disclosed for controlling the current flow through a load, such as a d-c servo motor. The amplifier includes a plurality of switching elements connected in bridge fashion with the load and a predetermined power source for coupling the load across alternate output terminals of the power source in accordance with the levels of a plurality of control signals respectively coupled to the plurality of switching elements. Logic circuitry, when enabled, couples each of the control signals to their respective switching elements for controlling same. Sensing circuitry is coupled to the load for generating an actual current signal indicative of the actual level of current flow through the load. A current limiter is coupled to the sensing circuitry for comparing the actual current signal with high and low level limit signals and for generating a current disable signal when either the actual current signal exceeds the high limit signal or the low limit signal exceeds the actual current signal.

Abstract: The servo circuit is operable both in a dual and in a single mode and includes an analog gate for multiple gap inputs. Dual operation is required where more than one gap is involved such as in the situation where multiple electrodes are carried by a common machine tool ram. In the servo operation, the unwanted information over a relatively wide voltage range is eliminated and the more significant voltage excursions around the 30 volt or gap breakdown voltage level are employed. This compensates for the non-linearity that is inherent in the electrical discharge machining gap.

Abstract: A system is disclosed for positioning an instrumentality over a predetermined range in response to a digitally coded position signal. To effect a controlled reduction in the instrumentality movement, an operational amplifier is provided having a feedback circuit including a fixed resistor and a controllable switch connected across the resistor. The switch is selectively controlled to short circuit the resistor at a controlled rate to effect a controlled gain reduction for the operational amplifier.

Abstract: A motor control circuit of the Wheatstone bridge type is described for driving a direct current motor, selectively, in one direction or the other for the general purpose of automatically setting the diaphragm of a photographic camera in accordance with the light impinging on a photo-responsive element.

Abstract: A solid state electronic circuit for controlling a reversible direct curr motor from a voltage source such that it may be rotated in either direction. The reversible direct current motor is connected into a bridge circuit with semiconductor switching elements which provide that the full supply voltage is available for starting in either direction. A pair of comparators receives input signals from a triangular wave generator and a signal source and in conjunction with a cross-fire protection circuit generates the drive pulses which control the semiconductor switching elements.

Abstract: Motor driver/control apparatus employs a motor speed regulating amplifier configuration, e.g., two push-pull power amplifiers operable responsive to a motor speed-direction command input signal, and having the motor differentially connected between amplifier output ports. The amplifier(s) are supplied with an energizing potential of variable amplitude just sufficient for amplifier operation and to satisfy the then obtaining motor consumption. Accordingly, system power is effectively utilized; needless power drain avoided; and the amplifier cost and complexity is reduced since the amplifier need not dissipate inordinate source-supplied energy not required for motor actuation.In accordance with one further aspect of the present invention, a power supply switching regulator for a motor utilized in a radar application is operated at the radar pulse repetition rate. This produces a non-interferring zero frequency beat between the power supply and radar pulse rate in the radar receiver.

Abstract: A servo amplifier system includes first and second operational amplifiers, with the second amplifier having a low output impedance. A torque coil is connected directly from the output circuit of the first amplifier to the input circuit of the second amplifier free of any impedance elements which would tend to make the torque coil subject to frequency response variations. Various circuits are provided to feed back error signals from the output circuit of the second amplifier to the input circuit of the first amplifier. A test signal may be connected across torque coil to test the response of the accelerometer including the torque coil.

Abstract: A servo-system is provided for self-balancing systems using an ac servomotor capable of maintaining loop gain substantially constant irrespective of span adjustment and without capacitor coupling. It includes a direct-coupling dc amplifier for comparing input and comparison signals and amplifying the result, a servo amplifier having a differential direct-coupling amplifier with inverting and non-inverting input terminals, with feedback from its output to the inverting input terminal and a switch to the non-inverting input terminal operating at the same frequency as the ac power source for the servomotor, to maintain the loop gain constant irrespective of span adjustment, and means causing the ac servomotor to move a slide resistor to bring the compared signal into balance with the input signal.Provision is also made for receiving input signals from thermoelectric or resistance thermometers and balancing the system using these signals.