SU1653109A1 - Dc voltage converter - Google Patents

Description

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(21) 4691435/07

(22) 13.03.89

(46) 30 .. Bull. Number 20

(72) В „Р. Biryukov and N "IP Zenkin

(53) 621.314.058 (088.8)

(56) USSR Author's Certificate No. 801208, cl. H 02 M 7/537, 1979.

USSR author's certificate 963127, cl. H 02 M 7/537, 1978.

Author's certificate of the USSR 1141545, cl. H 02 M // 537, 1983.

(54) CONSTANT VOLTAGE CONVERTER

(57) 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 goal is to increase reliability by simplifying

scheme. The device contains a transformer 1, the extreme conclusions of the primary winding are connected via the first 2 and second 3 switching transistors with the second input terminal. The base-emitter transitions of the switching transistors 1, 2 are bridged by the first 4 and second 5 additional transistors, the bases of which are connected to the outputs of the master oscillator 8. When one of the additional transistors 4, 5 is locked by the signal of the master oscillator, the circuit of the base of the currently open base is broken a switching transistor, which causes the said transistor to turn off and change the polarity of the voltage on the windings of the transformer 1. 2 Il.

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ABOUT -

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

The purpose of the invention is to increase reliability by simplifying the circuit.

Figure 1 shows an electrical circuit of a constant converter.

figure 2 - current and voltage diagrams on the circuit elements

The constant voltage converter contains a transformer 1, the first 2 and the second 3 switching

transistors, the first 4 and second 5 additional transistors, the first 6 and second / resistors, the first master oscillator 8C

The device works as follows

When the power is turned on due to the non-randomness of the parameters, one of the transistors 2.3, for example 2, starts to open. The collector current of the transistor 2 is increased, induced in all the windings of the transformer 1 by an emf of the corresponding polarity (Fig 2). The positive feedback winding of transformer 1 is connected so that the induced emf in it opens transistors 2, 5 and closes transistors 3,4.

Switching of the transistors 2 and 3 starts at the moment when the closing positive voltage pulse arrives from one of the outputs of the master oscillator 8 to the base-emitter junction of the transistor 5 (plot 11, fig 2). The current in the base circuit of transistor 2 is interrupted and it begins to close. Therefore, the voltage induced in all the windings of the transformer (plot 9, fig. 2) decreases to zero and then changes its polarity. Now open

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transistors 3 and 4, and transistors 2 and 5 are closed. Transistors 2 and 3 are switched with the frequency of the master oscillator (plots 10, 11, Fig. 2) higher than the frequency of the multivibrator. Thus, the additionally introduced transistors 4 and 5 allow control of low-power signals, including pulsed levels of TTL chips. This makes it possible to reduce the number of elements of the device by about 2 times and thereby increase its reliability.

Claims (1)

Invention Formula A DC converter containing a transformer, the output winding of which is connected to the output terminals, the middle terminal of the primary winding is connected to the first input terminal, and the first and second extreme terminals of the primary winding are connected to the second input terminal through the first and second switching transistors, whose bases are connected through a resistor with a winding of positive feedback, the first and second additional transistors, the bases of which are connected to the outputs of the master oscillator, and the collectors to the first the findings of the first and second resistors, characterized in that, in order to improve reliability by simplifying the circuit, the conductivity of the additional transistors is opposite to the conductivity of the first and second switching transistors, the base emitter junctions of which are shunted respectively by the first and second additional transistors, the emitters of which are connected to the second input terminal, and the bases are connected to the second terminals of the first and second resistors, respectively. FIG. 2