SU1379923A1 - D.c. voltage converter - Google Patents

Abstract

The invention relates to electrical engineering, in particular, to an energy conversion technique, and can be used in secondary power supply devices. The goal is to increase reliability by improving the work symmetry. The introduction of a resistor between the base and the emitter of the unijunction transistor of the starting node of the inverter cell allows one to exclude circuits for the flow of the bias current to the base of the power transistor through the single junction transistor. 1 il.

Description

with

The invention relates to a technique for converting direct current energy into alternating current energy and can be used in devices for the secondary power supply of electronic equipment.

The purpose of the invention is to improve reliability by improving the symmetry of the work.

The drawing shows the printable circuit of the converter.

The converter contains power transistors 1 and 2 connected to transformer 3 having primary winding 4, feedback winding 5 and output winding 6. Extreme leads of primary winding 4 are connected to collectors of transistors 1 and 2. Feedback winding 5 is connected between the bases transistors 1 and 2. The collector of transistor 1 is connected to the cathode of diode 7, and the collector of transistor 2 is connected to the cathode of diode 8. The anodes of diodes 7 and 8 are connected and connected to the middle point of the primary winding 4 through a resistor 9.

Between the connected anodes of diodes 7 and 8 and the base of transistor 1, a single junction transistor 10 is connected, the emitter of which is connected via a resistor 11 to the anodes of diodes 7 and 8 and through a capacitor 12 to the emitters of transistors 1 and 2. The converter contains the first 13 and second 14 input terminals .

The Converter operates as follows.

When applied to a voltage converter, the power transistors 1 and 2 are closed. Diodes 7 and 8 are also closed. Starting from the moment the power is supplied, the capacitor I2 is charged through resistors 9 and 11. When the voltage on capacitor 12 reaches the threshold voltage of the single-transistor, the latter opens and the capacitor 12 is discharged.

0

5 0 5

0

P

five

It passes through the base-emitter junction of the power transistor 1. The power transistor 1 opens slightly, while due to the winding 5 a positive feedback circuit is closed and the converter is started. After starting the converter, the single junction transistor 10 is closed, and the capacitor 12 is discharged, since diodes 7 and 8 are alternately opened through open transistors 1 and 2 and the voltage between anode and diode 7 and 8 and second input terminal 14 becomes zero.

The absence of circuits through which current can flow through a single junction transistor improves the symmetry of the circuit and increases reliability.

Claims (1)

Invention Formula A DC converter containing an inverter cell on power transistors, one of which is connected to the output of the start node, the connection point of the first terminals of the first resistor and the capacitor of which is connected to the emitter of the unijunction transistor, the first base circuit of which is connected to the first input terminal through a second resistor and the second base circuit is the output of the start node, while the second capacitor lead is connected to the second input lead, and to the output electrodes of the power transistors The first electrodes of two diodes are connected, the second electrodes of which are combined, characterized in that, in order to increase reliability by improving the symmetry of the work, the point of connection of the second electrodes of the diodes is connected to the second terminal of the first resistor connected to the junction of the first base circuit and the second resistor.