SU700910A1 - Dc motor control device - Google Patents

Description

(54) DEVICE FOR CONTROLLING DC MOTOR MOTOR

This invention relates to adjustable electric drives and can be used in electric drives of film-making apparatuses.

A device for controlling a direct current electric motor, comprising a series-connected reference frequency generator, a frequency-phase discriminator, to the second input of which the output of a speed sensor is connected, and a motor speed controller 1, are known.

The specified device is the closest to the technical nature of the invention.

 A disadvantage of this device is the presence of a large overshoot in the zone of abrupt changes in load, characteristic mainly for electric drives of film-making apparatuses. Films are characterized by cyclical changes in the moment of resistance, which are caused by intermittent motion of the film. A large overshoot in the zone of sudden changes in load torque is due to a large disturbing effect on the control voltage outside the phase comparison zone as a result of sudden changes in the feedback sensor frequency with a small value of. The purpose of the invention is to reduce the overshoot of sudden changes in load at the time and increase the synchronism of rotation of the drive. This goal is achieved by the fact that a series-connected optocoupler

actuator, element AND, - delay line, trigger and voltage generator, the output of which is connected to the input of the motor speed controller, and the output of the optocoupler

The sensor is also connected to the second trigger input, and the output of the reference frequency generator is connected to the second input of the And element.

FIG. 1 shows a block diagram of the device; in fig. 2 is a diagram of his work.

The device contains a reference frequency generator 1 and a feedback sensor 2, connected respectively to

Claims (1)

different inputs of the frequency-phase discriminator 3, the output of which is connected to the control circuit 4 by the electric motor 5, as well as a correction chain connected in parallel to the frequency-phase discriminator 3, and the correction chain consists of the element Ib in series connected to the delay line 7, trigger 8 and voltage generator 9, and opto-sensor 10, the output of which with the second inputs of the element Ib and trigger 8. The process of stabilizing the speed is as follows. The feedback sensor 2 generates a pulse train with a frequency proportional to the rotational speed of the electric motor 5. The signals from the feedback sensor 2 are fed to one of the inputs of the frequency-phase discriminator 3. The other input of the discriminator 3 receives a signal from the reference frequency generator 1, - The phase discriminator 3 generates a control signal proportional to the phase matching of these signals, thereby maintaining synchronism of the rotation of the engine 5 (average of its speeds). The opto-sensor 10 mounted on the shaft of the obturator, records the moment of a certain position of the shaft of the obturator or grab. This position is determined by the onset of a sharp increase in load (moment (Start of the tooth transport by the grapple film), but with a slight delay in order to take into account the initial part of the transition process that occurs during intermittent film transport. At this point, the optron sensor 10 generates a control pulse triggering through 8, a rising voltage generator 9, the voltage of which is an additional control of the control signal 4 of the electric motor 5, resulting in a certain .c A repair equal to the duration of a sharp increase in load determined by the element 6 and the constant time of the delay line 7 is added to the power used to compensate for the disturbance caused by a sharp increase in the load. The time diagrams explaining the operation of the device are shown in Fig., where the output state of the optocoupler 10, 11; 12 is the state of the delay line 7; 13 is the state of the trigger; 14 is the state of the voltage generator 9; 15 is the change in speed within one cycle before the correction; 16 - introduction of additional power; 17 is the resulting rate change characteristic. The introduction of a correction chain into the speed stabilization system leads to a decrease in the overshoot zone caused by an abrupt change in load, to a decrease in aperiodic processes within one cycle, which increases the stabilization of the instantaneous speed, and this, in turn, leads to a more stable speed stabilization. It means that it will improve the quality of work of electric drives of film-making equipment. An apparatus for controlling a direct current electric motor comprising a series-connected reference frequency generator, a frequency-phase discriminator, to the second input of which a speed sensor output is connected, and an engine speed regulator, characterized in that, in order to improve the accuracy of speed stabilization, An optocoupler position sensor of the actuator, an element I, a delay line, a trigger and a voltage generator, the output of which is connected to the input, are connected in series regulating engine speed torus photocouple wherein the sensor output is also connected to the second input flip-flop and the second input of AND gate connected to the output of the reference oscillator. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 379031, cl. H 02 R 5/16, 1970. Fig. / 11 1i / 3 It sixteen ) Fig.2.