Abstract:
The method for monitoring the end positions of a controlling element having a servomotor (1) comprises the recognition of the end position, for instance by interruption of the flow of current to the servomotor by limit switches (4, 5), and the subsequent action of a control pulse of opposite direction on the servomotor in order to brake the servomotor.
Abstract:
A motor control device provided on an electric sewing machine comprising a brushless permanent-magnet motor and in combination with a magnetic pole sensor, rotational-speed and rotational-speed polarity detector for sewing machine, detectors for needle-position and needle positioning signal, and the control systems of speed and needle stagnation thereof; with the specific ways of controlling the needle stagnant position and the strength of the reverse current for braking the motor, simple structure, less power wastage and no wearable friction clutch and brake device are needed, a quick sewing machine starting, quick stabilizing of speed control and precise stagnation of the sewing needle at a preset position can be achieved.
Abstract:
There is provided a moving body control device comprising a motor for driving a moving body, detector for detecting the speed of the motor, memory for storing a program for the phase comparison control of the speed of the motor, and control means for controlling the motor according to said program by inputting the output from the detector.
Abstract:
The present invention provides a machine driving apparatus which is composed of a brushless motor for switching the energization phase of the stator winding in accordance with the position of a rotor with a permanent magnet being provided in a rotor as a machine driving motor, compares a speed instructing signal to be generated from a speed instructing unit 32 in accordance with the displacement amount of a machine pedal 31 with a speed detecting signal detected by a speed detector 44 to control the rotational speed of a motor 42, also damps in reverse operation the motor 42 with a stop instructing signal to be generated by a position instructing unit 33 in accordance with the operation of the machine pedal 31 and a needle position detecting signal detected by a needle position detector 46 to stop the machine needle in a given position.
Abstract:
An anti-plug reversing circuit for use with a variable speed D.C. motor which provides safe and fast motor reversing with dynamic braking. The circuit, by sensing counter-EMF, prevents the premature application of a voltage of opposite (reversing) polarity until the motor armature has come to a full stop. The circuit advantageously utilizes a three-wire control input, is low cost, easily manufactured and applicable for use with low cost D.C. motors.
Abstract:
The invention pertains to a control system (46) for controlling the supply of power to a motor (12) to produce plugging electrical braking and current limit control, including a circuit (60) for controlling the direction of energization of the motor (12), a circuit (88) for generating digital numbers representing command motor speeds, a circuit (14) for generating a data signal representing a plugging condition, a programmable data processor (18) for generating pulse trains in dependence on the plugging condition, and a power transistor element (40) for coupling power to the motor (12) in response to the pulse trains. By using state-of-the-art digital, integrated circuit and software technology, prior, essentially linear or discrete component technology, which is relatively unreliable, expensive and slow, need not be used.
Abstract:
A plugging control circuit in a silicon controlled rectifier (SCR) control for a series-connected direct-current vehicle-propulsion motor. The plugging control prevents the main SCR from pulsing when plug current is high, restarts the SCR pulsing when the plug current decays but with a reduced pulse width, and delays application of power through the main SCR for a time to allow the vehicle to first come to a halt before power is applied to move the vehicle in the opposite direction.
Abstract:
A circuit for controlling the operation of a bi-directional motor. A motor energized to run in one direction is stopped by applying a reverse or braking current to its energizing field. When the motor is virtually stopped, means are provided to de-energize the motor to prevent the motor from reversing direction.
Abstract:
A separately excited speed-controlled D.C. motor which has constant armature current and pulse-controlled field current has its armature connected by way of a bridge rectifier and an inductor to an A.C. source of substantially greater r.m.s. voltage than the rated supply voltage of the armature, the inductor serving to regulate the armature current. The field winding is connected to a field excitation supply and to a thyristor chopper and the mean current through the field winding controlled by the thyristor chopper thereby to control the armature torque and therefore the speed. The field winding may comprise two field coils arranged to produce opposing magnetic fields, the thyristor chopper serving to control the net magnitude and direction of the motor field. A thyristor chopper may be provided in the armature circuit to maintain a constant armature current during plugging of the motor.
Abstract:
A claw mechanism for the transport of a film in a film projector. A claw arm is disposed parallel to the transport path and pivotable about an axis transverse to the direction of transport; a claw means is disposed substantially transverse to the transport path, pivotally connected to the free end of the claw arm about an axis transverse to the direction of transport; and a drive shaft disposed parallel to said two axes, which rotates continuously during operation, comprises a crank which engages a slot in the claw means. A cam follower, pivotally connected to the free end of the claw arm about an axis parallel to the direction of transport, is pressed against one of two cams on the drive shaft by spring force and is connected to the electromagnetic control means for engagement alternatively with a first cam for keeping the film perforations out of engagement with the claw means, or a second cam for intermittently advancing the film by one frame per revolution to control the movements of the claw arm and thus the speed of film transport.