SU1374370A1 - Variable a.c. to a.c. converter - Google Patents

Abstract

The invention relates to electrical engineering. The purpose of the invention is to simplify and increase reliability. At the beginning of each half-cycle of the supply voltage, depending on its polarity, one of the thyristors 7 or 8 is turned on, the transformer 1 is operating in a lowering mode. Then, at a certain moment, depending on the magnitude of the input voltage, the control unit 16 turns on one of the thyristors 9 or 10, the transformer remaining part of the half-cycle is operating in the boost mode. At the same time, the reverse voltage of the winding 3-5 of the transformer 1 is applied to the thyristor 7 or 8 that worked earlier. When the input voltage changes, the control unit G6 automatically changes the switching time of the thyristors 9, 10 in such a way that the output voltage removed from pins 4-6, remains stable. 1 il. 1C (L

Description

00 Nj

four

00

ten

15

11374370

The invention relates to electrical engineering.

The purpose of the invention is to simplify and increase reliability.

The drawing shows a schematic diagram of a device for stabilizing an alternating voltage.

The device contains a transformer 1, made in the form of an autotransformer with pins 2-6, of which pins 3 and 5 are adjusting lower and higher stages, respectively, pin 4 is an output tap, pin 6 is a common pin, pin 2 is an additional winding pin, a thyristor switch consisting of thyristors 7 and 8, and a thyristor switch consisting of thyristors 9 and 10, a trigger pulse generator I1, connected to the control output of the thyristor 7, a resistor 12, connecting the thyristor anode. 8 with its control terminal through diode 13 and through diode. 14 - with pin 2 of the additional winding of the transformer 1. The common connection point of both of the thyristor switches is connected to the input pin 15. The control unit 16, powered by the second additional winding 17, is connected to the control terminals of the thyristors 9 and 10.

20

25

thirty

to h q

The device o works as follows.

At the beginning of each half-period of the supply voltage, depending on its polarity, one of the thyristors 7 or B is turned on, the transformer 1 is operating in a lowering mode. Then at a certain moment, depending on the magnitude of the input voltage, the control unit 16 controls the corresponding thyristor 9 or 10, the transformer

with voltage sensor and output amplifier. Thyristors 7 and 8 have separate control circuits. The thyristor 7 is controlled by a driver 11 for triggering pulses. The thyristor 8 is turned on by the current from the anode through a resistor. 12 and diode 13. In this case, a voltage appears in the additional winding 2-3 of transformer I, which through diode 13 is applied to diode 14 in the opposite direction and prevents the control signal from bypassing through winding 2-3, the thyristor 8 shunts its power a control circuit consisting of resistor 12 and

diode 13, and the reverse voltage of winding 2-3 of transformer 1 is applied to diode 14. After switching on the thyristor 9, the thyristor 8 and, therefore, JK diodes 13 and 14 are applied, with a reverse winding voltage of 2-3-. and there is no current in the thyristor control circuit 8. In the next half-period, when the thyristor 10 is turned on after the thyristor 7 is working, and the reverse voltage of the winding 3-5 of the transformer 1 is applied to the thyristor 7, which is direct for the thyristor 8, the thyristor 8 cannot turn on, because the additional voltage windings 2-3 are applied to the diode 13 in the opposite direction and the current flowing through the resistor 12 is shunted through the diode 14 and winding 2-3.

Claims (1)

Invention Formula An adjustable AC-to-voltage converter that contains a transformer whose primary winding is high. with adjusting pins, thyristor keys according to the number of adjusting pins, made in the form of counter-pas 50 1 the remaining part of the half-period is parallel to the connected thyristors and melts in an upward mode. At the same time, the reverse voltage of the winding 3-5 of the transformer 1 is applied to the thyristor 7 or 8 that was previously operated. 6, remains stable. The control unit-16 may consist, for example, of the following nodes: a voltage synchronizer, a saw-tooth voltage generator connected in series 55 associated with the corresponding control leads, the control unit whose output is connected to the control leads of the bi-directional thyristor keys associated with the adjusting leads of the highest control stage, the driver of the thyristor trigger pulses associated with the adjusting lead of the lower control step, different the fact that, in order to simplify and increase reliability, the driver of the thyristor trigger pulses connected with the cathode parallel connected thyristors and associated with the corresponding adjusting pins, the control unit, the output of which is connected to the control pins of the bi-directional thyristor keys associated with the adjusting pins of the higher regulating stage, the driver of the thyristor trigger pulses associated with the adjusting output of the lower regulating stage, characterized by In order to simplify and increase reliability, the driver of the thyristor trigger pulses associated with the cathode with the regulator At the same time, the lower stage of the regen-serially connected lithium diode is made in the form of an additional one — connected to the control output of the pilot winding of the transformer, on the switch connected to the cathode and the primary winding of the lower stage, sequentially, In addition, the anodes of the diode of the additional winding of the transformers are combined and connected to the thyristor anode through a resistor of the resistor, but connected to a lower control level, but It is the cathode with the adjusting output of its other output through two opposite | Q houses of the lower control level.