SU1252896A1 - D.c.electric drive - Google Patents

Abstract

The invention relates to electrical engineering, in particular to actuating mechanisms of automation systems. The purpose of the invention is to increase reliability by providing a linear law of inhibition. The electric drive contains an electric motor (E) 1, keys 2, 3, reverse diode 4, pulse-width modulator (PWM) 5, pulse shapers 6 and 7. The relay element (RE) 8 and 13 of the switching unit 9, the integrator 10, comparator (K) 11, key 12. to SP to 00 f Od

Description

If there is a control signal at the PWM input 5, the switching unit 9 generates a signal that permits –– PWM operation 5 and prohibits the passage of a signal from output K 11. In the absence of a control signal at the outlet of RE 8, the voltage changes abruptly, PWM 5 unlocks key 2 and locks the key 3. At the same time, the integrator 10 generates a sawtooth voltage, which is compared to

The invention relates to electrical engineering and can be used in actuators of various automation systems.

The aim of the invention is to increase the reliability of the electric drive by providing a linear law of braking,

The drawing shows a diagram of the device.

The electric drive contains the electric motor 1 connected via the first switch 2 to the power source, the second switch 3 and the reverse diode 4 connected in parallel to the electric motor 1, the pulse-width modulator - torus 5, whose outputs through the first 6 and second 7 pulse shapers are connected to control inputs of the first 2 and second 3 keys. The device is connected in series with the first relay element 8, switching unit 9, integrator 10, comparator 11 and third key 12, as well as the second relay element 13. The pulse width modulator 5 and the second driver 7 pulses are provided with additional inputs the output of switching unit 9 is connected to an additional input of a pulse-width modulator by controlling the input of the third key 12, the output of which is connected to the additional input of the second shaper 7 impulse, the input of the first relay element 8 a first input ene Rotne Shih-width modulator 5, a second input of the relay member 13 and the second comparator 11 vhbd - with an electric motor 1, and the output of the second reley-

It is driven with a current voltage value proportional to the speed of rotation E 1. The K 11 opposite-polarity pulses drive the key 5, providing

mode controlled dynamic braking. The rate of the braking process is determined by the constant integration time. After stopping E 1 at the output of the operating system, a voltage jump brings the circuit to the initial state. 1 Il.

Line element 13 is connected to the second input of the switching unit 9.

The device works as follows.

When there is a control signal at the input of the pulse-width modulator 5, the output from the switching unit 9 is a signal that permits the operation of the pulse-width modulator 5 and prohibits the passage of the signal from the output of the comparator 11.

When the control signal is removed at the output of the first relay element 8, a voltage surge occurs, which is fed to the first input of the switching unit 9 and changes the state at its output, under the action of which the pulse-pulse modulator 5 switches to the mode wherein the first key 2 is open, and the second key 3 is closed. At the same time, a sawtooth voltage is formed at the output of the integrator 10, which post falls on the first input of the comparator 11, where it is compared with the current value of the load proportional to the rotational speed of the electric motor 1, which is fed to its second input.

At the output of the comparator 11, there are different polarized voltage pulses depending on the current relationship between the sawtooth voltage from the output of the integrator 10 and the voltage on the engine, which through the third switch 12 closed at that time is fed to an additional , the input of the voltage driver 3 and the time of the on and off states of the second switch 5 are controlled by the time

thus ensuring controlled dynamic braking.

The rate of the braking process is determined by the constant integration time.

Upon completion of the braking process, the voltage across the motor t drops to zero and a voltage jump will occur at the output of the second relay element 13, which is applied to the second input of the switching unit, bringing the circuit back to its initial state.

Claims (1)

Formula invented A DC motor containing a motor connected via a first key to a power source, a second key and a reverse diode connected in parallel to the motor, a pulse-width modulator whose outputs through the first and second pulse drivers are associated with the control inputs of the first and second keys, characterized in that, in order to increase reliability, the first relay element, a switching unit, an integrator, a comparator and a third key, a second relay element, a pulse-width module are introduced into it the torus and the second pulse shaper are equipped with additional inputs, while the output of the switching unit is connected to the auxiliary input of the pulse-width modulator and the control input of the third key, the output of which to an additional input of the second shaper mpulsov 1, the input of the first relay element is connected to the first input and shipotno-mylcnogo modulator input of the second relay element and the second comparator input - to the motor, and the output of the second relay element is connected to the second input of the switching unit.