SU1241397A1 - D.c.electric drive - Google Patents

Abstract

This invention relates to electrical engineering and can be used in an automated direct current drive. The purpose of the invention is improving the accuracy of stabilization speed. The device contains a motor. 1, speed sensor (DS) 2, pulse shaper 3, differentiating unit 4, standby multivibrator 5, summing amplifier 6 and integrator 7. The introduction of the frequency comparison unit 8 and its connection in appropriate way ensure a comparison of half the follow-up period of DS 2 signals and the reference interval of time. In addition, the drive provides a reduction in the time the engine exits at the rated speed. 2 Il. (About 4: d9; about

Description

25

The invention relates to electrical engineering and can be used in an automated DC electric drive with high accuracy of stabilization of speed.

The purpose of the invention is to improve the accuracy of stabilization speed.

Fig. 1 shows a diagram of the direct current drive in Fig. 2, voltage plots. JO

The DC motor contains a motor 1, a speed sensor 2 connected in series, a pulse shaper 3, a differentiating unit 4, a standby multivibrator is 5, and a summing amplifier 6 and an integrator 7, frequency comparison unit 8, one of which is connected to the output of shaper 3 pulses, the other input - with the output of the despairing multi-vibrator 5, and the outputs of the comparison unit 8 of the frequencies through the series-connected summing amplifier 6 and the integrator. 7 are connected to the engine 1. The standby multivibrator 5 comprises a series-connected pulse generator 9, a counter 10 and a trigger 11, while the second input of the trigger 11 is the input of the standby multivibrator 5, the output of which is the output of the trigger 11 connected to the counter input of the counter ten.

The drive works as follows.

The operation of the electric drive is based on synchronizing the engine speed by comparing half the period of signals from the output of speed sensor 2 with the reference time interval generated by the standby multivibrator 5. At the same time, each speed sensor 2 signal determines the formation time of each reference time interval. The device is turned on by applying voltage to it.

The shaper of 3 pulses, realizing itself, for example, on a Schmidt trigger, has at the output a trigger 1 in the absence of a pulse from speed sensor 2 and a signal O in the presence of a specified pulse at the input.

Thus, at the moment the device is turned on, the first input of the frequency comparison unit 8 receives the signal 1 (A), the second input receives the signal O (B), which corresponds to the acceleration mode of the engine 1. At the same time, the difference signal (A B) from the first output blo30

35

40

4S

SO

As the frequency comparison 8 arrives at the non-inverting input of the summing amplifier 6, then the integrator 7 and the motor 1, which begins to rotate. An alternating voltage whose frequency is proportional to the rotational speed of the output shaft of the engine 1 ' of: speed sensor 2 (Fig. ≪ 2 >) the post falls to the input of the pulse generator 3. From the output of the imaging unit 3 pulses, the voltage (Fig. 2S) is fed to the input of differentiating unit 4, which produces narrow pulses (Fig. 21} These pulses from the output of differentiating unit 4 are fed to the input of trigger 11. On trigger 11, a counter 10 and a generator 9 pulses, pulses of a reference duration are formed. A pulse arriving at the first input of trigger 11 from differentiating unit 4 places the trigger in position. Signal 1 from the output of trigger 11 (Fig. 2a), representing the first input of counter 10, which starts counting pulses a stable frequency applied to its second input from the pulse generator 9. When the total number of pulses arrives at the output of the counter 10, a pulse O is generated and the counting stops. When the next pulse from the differentiating unit 4 is fused, the cycle repeats. The output of the trigger 11 forms a signal (Fig. 2m,), which is a sequence of pulses of the reference duration, the frequency and duty cycle of which is proportional to the speed of rotation of the shaft of the engine 1.

The signals of the alon duration are strictly in phase with the signals of the speed sensor 2, which ensures the stability of synchronization in a large control range and the reliability of the device operation. In block 8, the frequency is compared to half the period of the speed sensor 2 signals with a reference interval of 1 time and output to one of two outputs (Fig. 2e, g), depending on the error sign (A B,), a sequence of pulses proportional to the fiacTOT difference between the measured and reference signals. The signals from the outputs of the frequency comparison unit 8 are fed to the corresponding inputs of summing amplifier 6, where they are amplified and fed to the input of integrator 7. The signal from the output of integrator 7 controls the engine in such a way as to eliminate the mismatch between the actual speed of the output shaft of the engine 1 and its setpoint Speed : the rotation of the device is changed by changing the frequency of the pulse generator 9 or by changing the volume of the counter 10.

Thus, the proposed electric drive provides an increase in the accuracy of engine speed stabilization by comparing half the period of the speed sensor signals and the reference time interval. In addition, the drive provides a reduction in time

Claims (1)

engine running at rated speed. Invention Formula  A DC motor that contains a motor, a speed sensor connected in series, a pulse shaper, a differentiating unit, a waiting multivibrator, and a summing amplifier and integrator, characterized in that, in order to improve the accuracy of stabilizing the speed, a frequency comparison unit, one input is connected to the output of the pulse driver, another input to the output of the waiting multivibrator, and the outputs of the frequency comparison unit through successively connected summing | amplifier and integrator Op compounds iny to the engine. at Well Editor E. Kopcha Compiled by Y. Vorobiev Tehred L. Oleynik Proofreader M. Maksimishinets Order 3609/52 Circulation 631. Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 P fig 2