SU959246A1 - Apparatus for controlling dc electric motor speed - Google Patents

Description

(5) DEVICE FOR REGULATING THE SPEED OF DC MOTOR MOTOR

one

The exemption relates to electrical engineering and can be used in automation devices, telemechanics, magnetic recording equipment, and a number of other devices for controlling the speed of DC motors.

A device is known in which an electric motor is powered by a pulsed voltage, and the counter-emf measurement is made in the pauses between the pulses of Cl.

The closest technical solution to the present invention is a device. for controlling the speed of a direct current electric motor, containing a power source connected to a motor core circuit, a program setter connected to a comparator input, the second input of which is connected to a motor core circuit, a comparator output connected to a power switch.

included in the electric motor circuit, pulse generator 2.

The disadvantage of these devices is the relatively low accuracy of the speed control of the electric motor due to the fact that the speed control process is pulsed. At the time of applying a voltage to the engine, a voltage pulse arrives, the amplitude of which is

to the magnitude of the supply voltage, and the engine begins to accelerate sharply. In the pause, the voltage from the engine is completely removed and it dramatically slows down. Engine speed,

J5 thus varies relative to a predetermined wide range, and in a number of cases, the accuracy of maintaining the speed of the electric motor 8 times provided by these devices,

20 does not appear to be sufficient.

Claims (2)

The purpose of the invention is to improve the accuracy of motor speed control. The goal is achieved by the fact that an analog key is additionally introduced into the device, a two-terminal current and an AND element, and the output of the pulse generator is connected to one input, the AND element; to the second input of which the output is connected to the parator, the second input of the comparator is connected to an analog switch, one input of which is connected to the electric motor core, and the second to the output of the element I, and to the power switch, the core of the electric motor is connected to the power supply through a current generator of two poles The drawing shows the device diagram. The device contains a direct current motor 1, the output of the generator 2 pulses is connected to one input of element 3 I, to the second input of which the output of comparator 4 is connected, the second input of comparator is connected to analog switch 5i one input of which is connected to the electric motor 1, and with E 1 of the element 3 And and with the power switch 6, included in the electrical motor 1 core circuit, the measles of which is connected to the power source through a tozoz giving a two-terminal 7, program setpoint 8, connected to the input of the comparator. The device works as follows. After switching on, the pulses from the generator 2 through the open, the element 3 and the power switch 6 are fed to the electric motor U. The engine 1 starts to accelerate, the value of the back-EMF core increases. The mode of operation of the analog key is chosen so that at the moments of arrival of the supplying pulses to the bark, the key 5 is closed, when there is no pulses, it is open and the magnitude of the counter-EMF is input to the input of the paratator kf and the second input receives the reference voltage from program 8 . Therefore, at the moment when the counter-EMF exceeds the reference voltage, the comparator k triggers and closes element 3 I. The feeding pulses do not flow to the engine, its speed begins to decrease, and at the moment when the counter-EMF becomes less than the reference voltage, the comparator k returns to the initial state and the pulses from the generator 2 through the opened element 3 And and the key 6 are fed to the engine, maintaining its speed around a predetermined value. At the moments when the power switch 6 is closed, the current passing through the winding ykor is not equal to zero, but is determined by the current setting two-pole 7. The adjustment process is somewhat smoothed, the maximum deviations of the speed from the nominal become less, the accuracy is adjustable. rises. In addition, such a connection of the two-terminal 7 allows to eliminate the dependence of the speed on the voltage of the power source. This is achieved due to the fact that during the pauses between the supply pulses to the input of the comparator k, the sum of the voltages is applied through the analog switch 5: OPTIVE-E4C core and the voltage drop on the core winding created by the current flowing through the two-terminal circuit 7, the current of which depends on the value I have something to stress. Thus, the proposed device provides a more accurate formation of pulses, powered by an electric motor, and consequently, more accurate speed control. Claim device A device for adjusting the speed of a permanent toKa electric motor, comprising a power source connected to the electric motor's main circuit, program set-up connected to the comparator input, the second input of which is connected to the electric motor's main circuit, the comparator output connected to the power switch included in A motor core circuit, a pulse generator, characterized in that, in order to improve accuracy, an analog switch, a current-supplying two-port network and an element are additionally introduced into it. And, the output of the pulse generator is connected to one input of the element I, the second input of which is connected to the output of the comparator, the second input of the comparator is connected to an analog key, one input of which is connected to the motor bark, and the second to the output of the element Measles electric motor59592 16 " tel connected to power supply 1. Patent of England t 13 "28 9, through tokoyadusayuschiy dvukhpolyusnik.kl. G 3 R, 1970. Information sources, 2. USSR author's certificate taken into account in the examination -W 639115, cl. H 02 P 5/16, 1978. ffti / m -0 I 6