SU1244776A1 - D.c.voltage converter - Google Patents

Abstract

This invention relates to electrical engineering and can be used in secondary power supply sources. The purpose of the invention is to increase reliability by eliminating the simultaneous open state of transistors. When the control switch 9 (10) is closed, current flows through the resistor 11 and the transistor (T) 1 (2) opens. The collector current T 1 (2) through the resistor 17 and the diode 16 opens T 4 (3). Failure in the control unit of the device does not cause failure of T 1-4 transistors. When the control keys 9 and 10 are closed, T 1 and 2 will be open at the same time, and T 3 and 4 will be closed, as the currents of their bases will be shunted by keys 9 and 10 through diodes 13 and 14. At the same time, the base currents decrease to zero during switching diodes 13 and 14, which is very small. Thus, the through currents through the transistors are determined only by the charge of minority carriers in the bases of the transistors due to the introduction of diodes 13-16. 1 il. with o (L yu 4 4 Od

Description

The invention relates to electrical engineering and can be used in the sources of secondary power supply systems of radio engineering, automation and computer technology.

The aim of the invention is to improve the reliability of the voltage converter by eliminating the simultaneous open state of the transistors.

The drawing shows a diagram of the proposed device.

The constant voltage converter contains the first, second, third and fourth transistors 1-4, whose control junctions are bridged by resistors 5-8, the first 9 and second 10 control keys, resistors 11, 12., two pairs of diodes 13, 14 and 15, 16 and two current-limiting resistors 17, 18.

The converter of a constant eg xeni works as follows. In the initial state, the control keys 9 and 10 are open and the transistors 1-4 are closed. The current in the load is external. there is.

When the control key 9 is closed, a current arises through the resistor 11, which opens the transistor 1. The collector current of the transistor 1 through the resistor 17 and the diode 16 opens the transistor 4, and a positive (conditionally) direction flows in the load. laziness. After opening the key 9, the converter returns to the initial state.

Similarly, when the control key 10 is closed, transistors 2 and 3 are opened and the current flows in a negative (conditional) direction in the load.

In normal operation, the control unit. control (they use keys to provide control pulses without overlap in time. However, as in any device, a control unit may cause a failure or malfunction with — which both control units: (9, 10 control signals leading to their closure, which usually leads to failure

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cellular transistors. In this converter, when two keys 9 and 10 are closed, both transistors 1 and 2 are open, and transistors 3 and 4 are closed, because currents from the bases are shunted by keys: 9 and 10 through diodes 13 and 14,

When the control keys 9 and 10 are closed, the base currents of the transistors 3 and 4 are reduced to zero during the switching time of the diodes 13 and 14, which are very small, and therefore the through currents through the transistors are determined only by the charge of the minority carriers in the bases of the transistors.

Claims (1)

Invention Formula Constant voltage converter containing the first and second. swarm transistors, the emitters of which are connected to the first input terminal of the converter, the control transitions are bridged by resistors, and the collectors are connected to the first and second output terminals of the converter and the collectors of the third and fourth transistors, the control transitions of which are bridged by resistors, and the emitters are connected to the second input terminal of the converter, the first and second control keys, the first terminals of which are connected to the second input terminal of the converter, and the second terminals with Dineny through resistors with bases, respectively, of the first and second transistors, two current-limiting resistors, which are based on the fact that, with the aim of increasing, reliability by eliminating the simultaneous open state of the transistors, two diodes connected by cathodes are introduced into it to the second terminals, respectively, of the first and second control keys, and the anodes, to the anodes of two, other inserted diodes and through current-limiting resistors, respectively, to the second and first output terminals of the converter, while the cathode the other two diodes are connected to the bases of the third and fourth transistors. Subscription