SU1023585A1 - One-cycle transistorized dc voltage converter - Google Patents

Abstract

SINGLE-TRANSACTOR CONSTANT VOLTAGE TRANSMITTER, containing APH (Yu transformer, power transistor, the base of which is connected to the junction point from-: Pirankhde and e sh) and trachea anne and stor, which are connected consistently, and the type of conductivity I, I. .., ...,. I -f .. .....; iV, 4 I p- .i. (Id Sfi vTyaTHiJA of the wound and power transistors are the same and the input transistor associated with the base of the blocking transistor, in order to increase Efficiency, a R C-chain is inserted in the converter, connected between the input terminals of the converter, and a current reference, a resistor connected to the emitter circuit of the transistor, whose conductivity type is opposite to the power transistor, and the base of the transistor unlocked is connected to an intermediate point (C-chain a parallel condensate The ATSF RC circuit switched on the entered discharge transistor, the base of which is through the specified input transistor and ballast (the L resistor is connected to the base of the blocking transistor. tND 00 SL 00 SL

Description

The invention relates to electrical engineering and can be used in power supplies for automation systems and radio electronics.

Single-ended transistor DC voltage converters are known, in which the power transistor is controlled by a current transformer, which ensures the proportionality of the base current of the power transistor to the collector current f and 21

The disadvantage of these devices is the difficulty of miniaturization due to the presence of a winding element - a current transformer.

The closest to the proposed technical entity is a single-ended DC / DC converter containing an output transformer, a power transistor, an unlocking and a locking transistor, having the same type of conductivity with a power transistor, connected in series with the locking transistor connecting point with the locking transistor. to the base of the power transistor, and the base of the blocking transistor is connected to the collector of the input transistor, the emitter of which is connected to the input terminal PP converter.

- However, in the famous converter

the base current is not proportional to the collector current of the power transistor, which causes significant losses in the control circuit.

The purpose of the invention is to increase efficiency.

The goal is achieved by the fact that in a single-stroke transistor converter voltage, containing an output transformer, a power transistor, the base of which is connected to the junction point of the unlocking and locking transformers connected in series, the conductivity type of the locking and power transistor is the same, and the input transistor connected to the base of the blocking transistor, are introduced in series with an RC circuit, connected between the input terminals of the transducer, and the current setting resis the torus included in the emitter circuit of the enabling transistor, the conductivity type of which is opposite to the power transistor, the base of the enabling transistor is connected to the intermediate point of the Rc-chain, and parallel to the RC circuit capacitor the input transistor is connected, the base of which is through the specified INPUT transistor and ballast resistor connected to the base of the blocking transistor.

The drawing shows a diagram. proposed converter.

The Converter contains a power transistor 1, in the collector circuit

which included the primary winding of the output transformer 2. The base of the transistor 1 is connected to the junction point of the unlocking 3 and locking 4. transistors.

The emitter of transistor 3 is connected via a current-generating resistor 5 to the input terminal of the converter, and its base is connected to an intermediate point of an RC chain consisting of capacitor 6 and resistor 7, and a collector of the discharge transistor 8, the base of which is connected to the collector of the input transistor 9. Base the transistor 4 is connected via a ballast resistor 10 to the emitter of the input transistor 9, the base of which is the input for clock pulses.

The Converter operates as follows.

When the input synchronization pulse appears at the base of transistor 9, the latter opens, as a result of which the discharge transistor 8 and transistor 4 are opened. If the capacitor previously had a charge on it, the voltage is shunted by the transistor 8. At this moment the power transistor 1 remains closed because the fero input is shunted by the transistor 4. This ensures the forced locking of the transistor 1, if it was previously opened, as accelerated absorption of the excess charge of the saturated transistor occurs

When the sync pulse is removed, transistors 8, 9, and 4 are also closed on the capacitor b. a voltage of approximately triangular shape begins to rise, which is determined for a given capacitance. capacitor: 6 by the value of resistor 7. This leads to the opening of the transistor 3 and the appearance of a triangular voltage on the tokadak resistor 5, which determines the base current of the power transistor 1,

Further, the processes are repeated.

Consequently, the shape of the base current of the power transistor 1 is determined by the law of voltage rise over the time of the master capacitor and, with the appropriate choice of circuit parameters, it can with a sufficient degree of accuracy ensure the proportionality of the base current to the collector current of the power transistor of the converter operating in the discontinuous current mode.

Thus, the present invention makes it possible to reduce the power taken by the control circuit from the primary source and the power dissipated by the circuit elements, to optimize the saturation level of the power transistor as a result of reducing the excess charge supplied to the base of the power transistor, which allows

31023585.

increase the frequency of converting the reliability of the operation of the convector due to the injection of direct current (increase the reduction of loads on the elements of the speed of the circuit), increase the circuitry of the converter.

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Claims (1)

(57.) A SINGLE-STROKE TRANSISTOR DC / DC Converter containing an output transformer, a power transistor, the base of which is connected to a connection point of a turn-on and turn-off transistor, is connected according to the type of conductivity of a single-wound, open and power transistor. kVD and the input transistor associated with the base of the locking transistor, characterized in that, p. In order to increase the efficiency, a serial R C-circuit is inserted into the converter, connected between the input outputs of the converter and the current supply, a resistor included in the emitter circuit of the turn-on transistor, the conductivity type of which is opposite to the power transistor, and the turn-on transistor base is connected to the intermediate point RC -chains, and in parallel with the capacitor of the RC-chain, the introduced discharge transistor is turned on, the base of which is connected through the specified input transistor and ballast resistor to the base of the blocking trans Stora