SU1264288A1 - Device for stabilizing rotational speed of d.c.electric motor - Google Patents

Abstract

The invention relates to electrical engineering and can be used in devices for stabilizing the frequency of rotation of DC motors. Improving the accuracy of the stabilization of the rotational speed of the electric motor 2 with the key 1 in the core circuit is achieved with fluctuations in the voltage of the power source by combining the power supply bus of the intergrading unit 6 and the pulse-width modulation node 5 with the power supply bus of the electric motor, 3 sludge.

Description

eleven

The invention relates to electrical engineering and can be used in devices for stabilizing the frequency of rotation of electric motors of direct current.

The aim of the invention is to increase the accuracy of stabilization of the rotation frequency.

, Figure 1 shows a block diagram of a device for stabilizing the rotation frequency of a direct current electric motor; 2 is a schematic diagram of an integrating node; FIG. 3 is a schematic diagram of a pulse-modulation node.

The device (Fig. 1) contains a switch 1, an electric motor 2 connected to the electric motor circuit 2, a generator of 3 pulses, a pulse sensor 4 of the rotational speed of the electric motor 2, a pulse-width modulation node 5, the output of which is connected to the control input of the key 1, and the first input the output of the generator is 3 pulses, and the integrating node 6. The input of the integrating node 6 is connected to the output of the pulse sensor 4 rotational speed, and the output to the second input of the node 5 is pulse-width modulation, and the power supply bus of the integrating node 6. and node 5 latitude pulse modulation with dineny with power bus elektpodg igatel 2.

Integrating node 6 figure 2). Consists of a transistor 7, a diode 8, a capacitor 9, resistors 10 and 11 and a diode 12,

The pulse width modulation node (FIG. 3) consists of resistor 13, transistor 14, capacitors 15, zener diode 16, resistors 17 and 18, transistor 19, resistor 20, diode 21, and resistor 22.

The device works as follows.

The pulse-frequency signal from the rotational speed sensor 4, connected to the input of the integrating node 6, via diode 12 is fed to the base of the active element - transistor 7, which is an emitter follower connected to the resistive divider 10 and 11 and the capacitor 9,

The emitter of transistor 7 through diode 8, the cathode of which is an output, is connected to the input of a pulse-width modulation node 5. The latter is implemented on two transistors 14 and 19 and performs the function of a new vibrator with

64288 2

by launching, at the output, pulses, the duration of which does not depend on the scatter of parameters of transistors, Node 5 of pulse-width modulation

5 is triggered by a positive pulse coming from the 3-pulse generator to the base of the transistor 14. Depending on the frequency of the input signal coming from the sensor 4, turn on the frequency 10 p |; en, the resistance changes: transistor 7 - diode 8 - capacitor 15 - transistor 14 is a shunt resistor 20. As a result, the charging current of the capacitor 15 changes, and, consequently, the duration of the output impulse taken from the collector of transistor 19, which controls CL1 of the electric motor 2.

20 Stabilization of the motor speed when the voltage of the power source is changed is realized by supplying the bias voltage from the motor power source to the base of transistor 7, as well as connecting the 5 pulse width modulation node to the indicated power source.

Thus, in the proposed device, the stability of the rotation frequency of the DC motor is increased when the integrating node and the pulse-width modulation node are powered by an unstabilized circuit.

Claims (1)

Invention Formula A device for stabilizing the frequency of rotation of a DC motor, comprising a key included in a motor core circuit, a pulse generator, a pulse frequency sensor of the motor, a pulmonary modulation node, the output of which is connected to the control input of the key, and the first input from the generator output impulses, integrating node, characterized in that, in order to increase the accuracy of stabilization of the rotational speed of the motor, the input of the integrating node is connected to the output of the pulse rotational speed sensor, and the output to the second input of the pulse width modulation node, and the power bus of the integrating node and the pulse width modulation node connects to the power supply of the electric motor.