Abstract: A control circuit can drive an electric motor such as a stepping motor and a DC torque motor within a wide supply voltage range so that its rotor follows a selected speed pattern without error. The control circuit includes a monitoring circuit for monitoring a level of the supply voltage to output a detection signal. The control circuit also includes a memory storing a plurality of speed patterns, the plurality of speed patterns corresponding respectively to different levels of the supply voltage. One of the plurality of speed patterns is selectively read in response to the detection signal. The electric motor is then driven in accordance with the read speed pattern.

Abstract: In a numerical control device for machine tools, a tool path is determined for a workpiece according to the machining data, and is divided into machining units, and the amount of machining for each machining unit is calculated to set a tool feeding speed data thereby to control the tool feeding speed of the machine tool.

Abstract: A system for the actuation of a setting element with a digital actuation device, particularly for a motor vehicle, wherein the digital actuation device is connected with a monitoring circuit which, upon failure of the digital actuation device, switches a by-pass of the digital actuation device. Preferably the digital actuation device comprises a microcomputer, from an output of which uniform signals are supplied during the course of the program, which signals are evaluated by the monitoring circuit.

Abstract: An apparatus for actuation of a setting element has a desired value transmitter and an actual value transmitter for the deflection of the setting element from a rest position. The apparatus includes an electronic controller, particularly for a motor vehicle, wherein the deflection of the setting element is proportional to an electric current fed to the element by the controller. An operating mode of the controller is provided by which a signal emanating from the desired value transmitter is converted into a current proportional to a desired value.

Abstract: The invention concerns an electrical signal generator system and its applications. According to the invention, the signal generator system includes at least one electric current generator of the photovoltaic cell type and an impulse generator fed by the cell, and delivering a signal which is a function of the electrical energy delivered by the cell. The invention is applicable in particular to driving a step-by-step motor or to feeding a light integrator.

Abstract: A stepping motor driving device of this invention includes: a first ROM for outputting an intermittent drive signal, a second ROM for outputting a continuous drive signal, a bus selector into which these signals are input, the bus selector also selectively outputting either one of these signals in response to a selection signal, and a driver for driving the stepping motor intermittently or continuously on the basis of the signal selected by the bus selector. In consequence, the stepping motor can be driven intermittently or continuously by a single driver.

Abstract: A switched reluctance motor is cyclically energized to operate at a desired speed. The energizing current is sampled at a predetermined time after the beginning of the cycle, the energizing current at that time being a function of rotor position. The sampled current value is compared with a reference to generate an error signal representative of the difference between the rotor position and the desired rotor position at the beginning of the cycle. The energization current is controlled in response to the error signal so as to correct the rotor position during the next cycle in the direction of the desired position. The energizing current is compared with the current limiting value derived from the error signal so that the current limiting value reflects the difference between the actual rotor position and the desired rotor position. The energizing current is limited to the current limiting value to correct the rotor position.

Abstract: A method and apparatus for moving a moving member of a positioning mechanism to a target position by means of a stepper motor as a driver. The method and apparatus alleviate the positioning error attributable to the hysteresis of the stepper motor, which is inherent in stepper motor drive systems, by controlling the oscillation damping condition when the stepper motor has entered a damped oscillation phase in the vicinity to the target positon. The damping condition is controlled by varying the solid friction factor of the mechanism or the drawback torque constant of the stepper motor.

Abstract: A stepping motor includes a primary side magnetic flux generator unit having a plurality of magnetic poles and a secondary side magnetic member provided rotatably in the primary side magnetic flux generator, characterized in the primary side magnetic flux generator unit generating a magnetic flux passing through a magnetic flux path formed by at least two of the magnetic poles and the secondary side magnetic member to produce an attraction force between the magnetic poles and the secondary side magnetic members for thereby moving one of the primary side magnetic flux generator unit and the secondary side magnetic member, the magnetic poles having coils respectively provided therebetween and having a semihard magnetic member provided over tip ends thereof forming a magnetic flux path among a plurality of the magnetic poles, the semihard magnetic member being magnetized by a magnetic flux produced in the magnetic flux path every time the magnetic flux is produced, the semihard magnetic member producing a magnet

Abstract: In a printer in which a printing medium is moved by a line-feed stepping motor during line-feed operation, and the line-feed stepping motor is stopped during printing operation and in a ready state, the line-feed stepping motor is caused to generate a first holding torque for preventing unwanted movement of the printing medium while permitting the operator to feed the printing medium manually, in the ready state of the printer, and the line-feed stepping motor is caused to generate a second holding torque which is greater than the first holding torque, during the printing operation.

Abstract: There is provided an optical scanning apparatus having an angular positioning means that is generally comprised of a variable capacitor including a rotor disc with a plurality of equally spaced conductors and a stator disc with twice as many equally spaced conductors axially spaced from the rotor disc for capacitive coupling. Excitation of the variable capacitor provides a feedback signal to the controller of the optical scanning apparatus that is proportional to the angular position.

Abstract: A microangle drive circuit for a stepping motor and the system therefor comprising output elements pairs of which are connected to one another in series, a sense resistance connected to the output elements in series to make a motor coil control circuit for a phase or coil, a stepping motor control circuit made for n-phases, and motor coils. These circuit and system increase accuracy in rotation and stop by dividing the rotation angles of the stepping motor into microangles.

Abstract: A stepping motor control device is provided with a current control circuit by which the levels of currents of different driving power sources arranged to drive a stepping motor are virtually continuously changed, so that the motor can be controlled at intermediate phases thereof.

Abstract: A servo-control system is provided for the steerable front wheels of a vehicle, particularly the steerable nose gear of an aircraft, at least the lower part of which having at least one wheel may rotate about its longitudinal axis. This system includes a high pass filter device whose input receives a signal containing at least a part representative of the oscillations about its longitudinal axis to which said lower part of said nose gear is subjected and whose output is connected to a device for subtracting the output signal of said high pass filter from said difference between said order and said signal representative of the real orientation, and the pass bank of said high pass filter covers the natural oscillation frequency of said lower part of the gear about its longitudinal axis.

Abstract: A two wire control circuit for a bidirection variable speed stepping motor having motor drive logic adjacent to the motor. The control signals are momentary pulses which are superimposed on the supply line. The very short duration pulses are not recognized by the motor, but are used to trigger the sequence of the motor drive logic and through a low pass filter, the same modulated power supply line can power the drive logic.

Abstract: In a servo-system of a conventional numerical control (NC) device, a delay in response or deformation is always observed on an output side with respect to an inputted speed command or position command and an actual output response behaves differently from a command value. Such delay or deformation of the output response constitutes a significant problem particularly in case of controlling one object simultaneously by a plurality of servo-system, which results in a remarkable defect in a controlling performance. According to this invention, when a transfer function of a servo-system of the type comprising a control system and a control object is designated by W, a device or a signal conversion system with an inverse function 1/W of the transfer function W is located a a pre-compensation system in advance of the control system thereby to input a speed or position to be controlled into the pre-compensation system.

Abstract: A commutator for a microcomputer based switched reluctance drive employs a selectively addressable non-volatile memory, e.g. a ROM, to store stator phase firing patterns and facilities selective adjustment of turn-on angle and pulsewidth of phase switching current pulses. Firing patterns differing only in pulsewidth of their respective pulses can be stored in different sections of the memory or in the same section where word bit width permits. The adjustment of pulse position and duration allows torque control of the motor over a very wide speed range.

Abstract: By examining parity for a bit combination representing the present phase state of a stepping motor, a selection can be made as to which phase state should be changed in order to produce rotation of the step motor in a predetermined direction. By including within the parity determination not only the present phase state of the stepping motor, but the logic level of a direction bit (DIR), appropriate phase sequence for either CW or CCW rotation can be selected. In a hardware embodiment of the invention, a conventional parity generator module is used with inputs representing the present motor phase states as well as a logic level for a DIR bit. The output of the parity generator then determines which phase state to change to produce the desired rotation. In a software embodiment, a digital computer dedicates a phase state byte with a bit from each motor phase state and an additional DIR bit. Parity can be determined using a conditional branch on parity instruction or merely summing the phase direction byte.