SU733043A1 - Device for controlling three-phase load switching circuit built abound trigger diode - Google Patents

Description

one

The invention relates to the field of control of starting and braking and can be used for electric pumps, fans, lifting mechanisms.

A device dp for controlling a triac switch of a three-phase load is known, which contains pulse triggers for controlling triacs equipped with a vertical-pulsed control circuit l. A disadvantage of this device is voltage dips during engine starting and the occurrence of shock moments.

The closest in technical essence and the achieved result is a device for controlling a triac switch with a three-phase load, containing triacs for controlling triacs connected through three single-phase transformers with star-connected primary windings to the load supply network, and connected to the network through an additional

the transformer is a common driver control unit equipped with a rectifier, a stabilizer, a sawtooth signal generator and capacitors, the outputs of the unit are connected to the inputs of the driver 2.

A disadvantage of this device is insufficient reliability.

 The purpose of the invention is to increase reliability by implementing a soft start load.

This goal is achieved by the fact that the control unit is equipped with two additional rectifiers and stabilizers, the generator and one of the stabilizers are made on composite transistors, and the outputs of each stabilizer are shunted by capacitors.

The drawing shows a diagram of the device.

Claims (2)

Asynchronous motor 1 is connected to the mains through triacs 2–4, which are shunted by chains 5. Triac control circuits include a mains-powered power supply unit of the synchronization unit, consisting of three single-phase transformers connected in a star, and the semi-winding 1O15 secondary windings are connected to the inputs of control driver formers 16–18, the outputs of which 19–21 are connected to the control electrodes of the triacs 2–4. In the control unit 22, the primary winding of the transformer 23 is connected to the mains, and the secondary windings are connected to sources of stabilized voltages via rectifiers 24-26. The output of the rectifier 24 includes a capacitor 2, the Zener diode 28, a resistor 29 and a clamp 30 with plates 31 and 32. The output of the rectifier 25 includes a capacitor 33, a resistor 34, a stabilized 35 and an amplifier at the composite transistor 36 and resistor 37, which are connected with capacitor 38 with plates 39 and 4O, the output of rectifier 26 includes a capacitor 41, a resistor 42, a Zener diode 43, an amplifier on a composite transistor 44, a switch 45, a resistor 46, a capacitor 47, a resistor 48 and a capacitor 49c with plates 50 and 51 When applied power supply on circuit and circuit breaker 45 b ca. 6 supplies the synchronization control conditioners 16-18 w boiling pulse voltage network voltage. EinOK control 22 supplies stabilized voltages, the first of which, taken from points 31 and 39, is used to supply the working circuits of the formers, the second, taken from points 32 and 40, through a resistor 52, is the bias voltage. And the third control voltage, taken from points 5O and 51, which changes when the starter is turned on l from the maximum value to zero. This happens as follows. When the circuit breaker -45 is closed, the charged capacitor 47 begins to discharge to the composite transistor 44, the output voltage of which smoothly changes. At the same time, the triacs 2-4 begin to open and when the control voltage is equal to zero, the triacs are fully open, the motor 1 goes to a natural characteristic. By changing the value of the resistor 46, you can adjust the engine start time. The invention is a device for controlling a triac switch with a three-phase load, containing triac control pulse drivers connected through three single-phase transformers with star-connected windings connected to the power supply network of the load, and connected to the network via an additional transformer common generator control unit equipped with a rectifier, stabilizer , the generator has a sawtooth-shaped signal and capacitors, with the outputs of the block being connected to the inputs of the drivers, excl Considering that, in order to improve reliability by performing a soft start load, the control unit is equipped with two additional rectifiers and stabilizers, the generator and one of the stabilizers are made on composite transistors, and the outputs of each stabilizer are bridged by capacitors. Sources of information taken into account in the examination 1. Pirozhenko V, X. Mine thyristor electric drive. Kiev, 1974, p. 93, fig. 40 2. Technical Reference Thyristors. M., Energie, 1971, p. 248, fig. 9-39 (prototype).