Abstract:
A brake control system of a motor is provided. When a control circuit intends to brake the motor, the control circuit controls a driver circuit to turn off a first high-side switch and a second high-side switch, and to fully turn on the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off one of the first low-side switch and the second low-side switch, and to continually turn on the other one of the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off the other one of the first low-side switch and the second low-side switch, and to turn on the one of the first low-side switch and the second low-side switch, for a period of time.
Abstract:
A control circuit includes a first high-side transistor coupled between a voltage supply terminal and the first terminal of a DC motor and a second high-side transistor coupled between the voltage supply terminal and the second terminal of the DC motor. The control circuit includes a first low-side transistor coupled between a ground terminal and the first terminal of the DC motor and a second low-side transistor coupled between the ground terminal and the second terminal of the DC motor. The control circuit includes a first pull-up resistor coupled between the voltage supply terminal and a gate terminal of the first low-side transistor and a second pull-up resistor coupled between the voltage supply terminal and a gate terminal of the second low-side transistor. The pull-up resistors apply bias currents to turn ON the first and second low-side transistors to provide a conductive path to brake the DC motor.
Abstract:
An actuating device for displacing a control device, such as a gate valve or other control mechanism, in particular for use in oil or gas production systems, includes a motor-gear unit and a threaded spindle drive, which is operable by said motor-gear unit. The threaded spindle drive includes at least a threaded spindle and a screw nut. The threaded spindle is displaceable in an essentially axial-direction so as to displace the control device between an advance position and a retracted position. The threaded spindle drive further includes a position holding means holding the attained position of the threaded spindle. The position holding means is directly connected to a motor shaft of the motor-gear unit so as to apply a holding torque to said motor shaft.
Abstract:
In a drive control circuit of a linear vibration motor, a drive signal generating unit generates a drive signal used to alternately deliver a positive current and a negative current to a coil. A driver unit generates a drive current in response to the drive signal generated by the drive signal generating unit and supplies the drive current to the coil. An induced voltage detector detects an induced voltage occurring in the coil. After a running of the linear vibration motor has terminated, the drive signal generating unit generates a drive signal whose phase is opposite to that of the drive signal generated during the motor running; this drive signal of opposite phase includes a high impedance period during which the driver unit is controlled to a high impedance state. The induced voltage detector detects the induced voltage occurring in the coil during the high impedance period.
Abstract:
In a drive control circuit of a linear vibration motor, a differential amplifier circuit includes an operational amplifier in which an P-channel type transistor is used as a transistor that receives an input voltage, and the differential amplifier circuit detects an induced voltage occurring in a coil. Before the H-bridge circuit is controlled to a high impedance state, a drive signal generating unit turns on a first transistor and a second transistor, and delivers a regenerative current through the coil, the first transistor, the second transistor and the power supply potential.
Abstract:
A method of breaking a motor includes the step of applying a pulse width modulated signal to the winding of the motor. A switching voltage is used to intermittently reverse the poles of the motor for selected time periods. The time periods are separated by pauses the duration of which is dependent upon the breaking force needed to stop the motor.
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.