SU881955A1 - Push-pull inverter - Google Patents

Description

(54) TWO-TIME INVERTER

I

The invention relates to a converter technique and can be used in power systems for electronic equipment.

Known push-pull inverter containing a transformer, transistors and the source of the din. chronizing pulses connected in series in the sending circuit of transistors 1.

The disadvantage of such a push-pull inverter is the loss of the power of the control signal and the decrease in the control current of the transistors, due to the presence of the internal resistance of the clock source.

Closest to the present invention is a push-pull inverter comprising a transformer, transistors and a synchronizing transformer, the secondary winding of which through counter diodes, connects to the bases of the transistors, and a resistor is connected between the common point of the diodes and the common terminal for connecting the source 2.

Dividing the control circuits and synchronizing the operation of the transistors reduces the shunting effect of the internal source resistance of the synchronized circuit.

impulses, however, in order to reduce the shunt effect, it is necessary to select diodes with such parameters that the voltage drop across the diodes exceeds the voltage across the bases of the transistors. When using silicon transistors, this condition is possible due to the series connection of several diodes, which complicates the device and at the same time does not completely eliminate the possibility of shunting transistors, mainly due to the strong dependence of the voltage on the collector current, temperature and transistor sample. Shunting leads to a decrease in the base current of the transistors, which may result in output

15 transistors from saturation and subsequent thermal breakdown. This disadvantage reduces the functional reliability of a known transistor inverter with a locking chain at the input of transistors.

20

The purpose of the invention is to increase efficiency.

The goal is achieved by the fact that a two-stroke inverter introduces an i capacitor, a shunt resistor.

The drawing shows the scheme of the proposed inverter.

The inverter contains a transformer 1, transistors 2 and 3, with bases which through a resistor 4 and diodes 5 and 6 are connected synchronize a transformer 7. Parallel) 1 is connected to a resistor 4 with a resistor 4. The collectors of transistors 2 and 3 are connected to the terminals of the transformer primary winding 1, and the bases with the leads of the secondary winding 9 of the control transformer 10. The primary windings of the transformers 7 and 10 are connected to the output terminals of the control unit 11.

The inverter works as follows.

The control unit 11 through the transformer 10 provides alternate switching of the transistors 2 and 3. In the end, each sub-period from the control unit through the transformer 7 to the bases of the transistors are supplied with blocking current pulses. The base voltage U, which supplies the base electrons of the transistors to the working creep, through the diodes 5 and 6, the winding of the transformer 7 charges the circuit voltage 8 in the polarity indicated on the drawing.

The locking synchronization pulses generated by the winding of the transformer 7 additionally charge this capacitor to a voltage higher than the same U. Therefore, in the interval between the synchronizing pulses, the diodes 5 and 6 are in the closed state.

The magnitude of the bias voltage on diodes 5 and 6 is determined by selecting the resistance of the discharge resistor 4. When the voltage Uj changes, for example, when a transistor is replaced, the voltage of the capacitor 8 changes by the same amount, as a result of which the bias voltage remains constant and the shunting of the base circuits of the transistors 2, 3 by the circuit 5, 6-7-4.8 is eliminated.

Switching a capacitor in parallel with the resistor allows reducing control power losses and increasing functional reliability.

Claims (2)

1. Moin V.S. and Laptev N.N. Stabilized transistor converters. Energy, 1972, p. 304, Fig. 9-26. 2. USSR author's certificate N 384181, cl. H 02 M 7/537, 1970.