SU1614088A1 - Multimotor electric drive of tape transport mechanism - Google Patents

Abstract

The invention relates to electrical engineering and can be used in device drives of tape-conducting mechanisms with collector three-phase electric motors. The aim of the invention is to increase reliability. As a sensor for loop loop sagging, selsins 8 with transformers 9 and 10 are used. Threshold elements 15, 16 with time delay elements 17, 18 of the motor frequency synchronization block allow you to set the time of relay 21 on and off depending on the value of the output signal of the selsyn. 22 testing the actuator to compensate for the change in the level of slack of the loop and thereby synchronize the operation of the electric motors of the tape drive mechanism. The use of threshold elements 15, 16 allows to exclude the accidental operation of the block 5. 2 Il.

Description

FIG. 2

The invention relates to electrical engineering and can be used in electric appliances with tape mechanisms.

The purpose of the invention is to increase the reliability of the device.

FIG. 1 shows a diagram of a tape drive mechanism; in fig. 2 is a block diagram of motor speed synchronization.

The electric drive of the tape drive mechanism contains two three-phase collector motors 1 and 2 with two auxiliary servomotors 3 and 4. The unit 5 synchronizes the rotation frequency of the motors 1 and 2, the sensor of the loop loop sag 7, made in the form of selsyn 8 with three output terminals.

The rotation frequency synchronization unit 5 is made in the form of two transformers 9 and 10 with one primary and two secondary windings each, four rectifiers 11-14, two zero-organs 15 and 16, two time delay elements 17 and 18, with four inputs and one output, two amplifiers 19 and 20, two relays 21 and 22 with coils and two adjustable resistors 23 and 24, two capacitors 25 and 26; One terminals of the primary windings of transformers 9 and 10 are combined and connected to one output terminal of the selsyn 8, the other two output terminals of which are respectively connected to other terminals of the primary windings of transformers 9 and 10. The terminals of the secondary windings of each of the transformers 9 and 10 are connected to the AC inputs rectifiers 11-14. The DC inputs of the first 11 and third 13 rectifiers are connected to the inputs of the corresponding nug-bodies 15 and 16, the outputs of which are connected to the first inputs of the corresponding time delay elements 17 and 18, the first DC output of the second 12 and fourth 14 rectifiers are connected to the second inputs of the time delay elements 17 and 18, which regulates the output and the first output of each adjustable resistor 23 and 24 are combined and connected to the second DC outputs, respectively, of the rectifiers 12 and 14, one output of each cond. Ators 25 and 26 are connected to the third inputs of the corresponding time delay elements 17 and 18, the fourth input of which is connected to the other terminals of the respective capacitors 25 and 26 and the second terminals of the respective resistors 23 and 24, the outputs of each of the time delay elements 17 and 18 through the respective series-connected amplifiers

19 and 20 and the coils of the relay 21 and 22 are combined and connected to the power supply bus. The device works as follows

The operation of the device is reviewed on

an example of one channel consisting of a transformer 9, a rectifier 8, a zero-body 15, an element 17, an amplifier 19). When the revolutions of the engines are equal, rural 8 is set to a position in which the voltage difference between the pins is equal and minimum, these levels of voltages are not processed by the zero-bodies 15 and 16. Zero-bodies 15 and 16 are activated only when the voltage exceeds the value established in the absence of a mismatch.

When the speed is not matched, the voltage taken from one secondary winding of the transformer 9 through the rectifier 11 is fed to the null organ 15. At the same time, permission is issued to work out the time delay from its output. The voltage taken from the secondary winding 5 of the transformer 9 connected to the time-master circuit on the resistor 23 and the capacitor 25 determines the dependence of the time delay on the voltage

During this time, through the power of the thal 19 turns on the relay 21 with a coil, which includes one of the servomotors 3 or 4 of the traverse movement with the brushes of the corresponding collector motor 1 or 2. The greater the initial 5 mismatch of rotational frequencies, the longer the servomotor . The level of sagging loop 6 of the tape 7 is restored, the signal from the output of the selsyn 8 decreases, the relay 21 with the coil disconnects the 0 servomotor. In the electric drive, the rotational frequency of the collector three-phase electric motors has been equalized. Similarly, another channel works.

The application of the invention makes it possible, by using a loop-selsyn as a sensor, by eliminating contact elements of the synchronization circuit of the rotational frequencies of electric motors and galvanically isolating the sensor and the control circuit, to increase the reliability of the electric drive of the tape drive mechanism.

Claims (1)

Invention Formula A multi-motor electric drive 55 of a tape drive mechanism, comprising two three-phase collector motors, two auxiliary servomotors for rotating the traverse of the brushes of the respective collector motors, a synchronization unit for the rotational speed of the motors, and a belt loop saver sensor, characterized in that, in order to improve reliability, the tape loop sag sensor is made in the form of selsynsin with three output pins, the synchronization unit of the frequency of rotation of the electric motors is made in the form of two trans formers with one primary and two secondary windings each, four rectifiers, two zero-organs, two time delay elements, with four inputs and one output, two amplifiers, two relays with a coil each, two adjustable resistors, two capacitors, one the primary windings of the transformers are combined and connected to one output terminal of the selsyn; two other output terminals of Kpjoporo are respectively connected to the other terminals of the primary windings of transformers, the secondary windings of each of the transformers rmatorov accession Nena to inputs AC, respectively first, second, third and fourth rectifiers outputs a DC current of the first and third rectifying - tifiers connected to inputs corresponding zero-organs, whose outputs are connected to the first inputs of the corresponding time delay elements, the first DC output of the second and fourth rectifiers are connected to the second inputs of the first and BToporti time delay elements, respectively, the middle and one of the outputs of each adjustable resistor are merged and are connected to the second DC terminals of the second and fourth rectifiers, respectively, one terminal of each of the capacitors is connected to the third input of the corresponding element Time delays, the fourth input of each of the time delay elements is connected to a different output of the corresponding capacitors and to another output of a corresponding adjustable resistor, the outputs of each of the time delay elements are connected to the input of a corresponding amplifier, whose outputs are connected to the coil inputs of the corresponding relays, outputs which are combined and intended for connection to the power supply bus.