SU1531205A1 - Power transistor gate - Google Patents

Abstract

The invention relates to a pulse technique and can be used as power transistor switches in inverters. The purpose of the invention is to expand the scope of application of a power transistor switch by allowing it to work with both active and reactive loads. The device contains an auxiliary transistor 2 and a power transistor 1, which form the first trigger pair, a low-voltage power supply 14, a bi-polar pulse input voltage source 11, the first and second resistors 5 and 7, the first and second isolation diodes 6 and 15, and the first reverse diode 4 current. To achieve this goal, an additional transistor 3, the second and third reverse current diodes 12 and 13, and the third, fourth, and fifth resistors 8-10 are introduced into the device. The additional transistor 3 and the auxiliary transistor 2 form a second trigger pair, allowing the power transistor 1 to operate normally with zero or low voltage on it when it is closed. 2 Il.

Description

The invention relates to a pulse technique and can be used as power transistor keys in inverters.

The purpose of the invention is to expand the scope of application of a power transistor switch by allowing it to work with both active and reactive loads.

FIG. 1 shows a circuit diagram of a power switch; 2 shows timing diagrams for the operation of the key.

The power transistor switch contains a power transistor 1, which, when paired with an auxiliary transistor 2, constitutes the first trigger pair allowing it to control short pulses.

 The auxiliary transistor 3, together with the auxiliary, constitutes the second trigger pair, which allows the power transistor to operate normally at zero or low voltage of the private key.

To implement the inverter mode, the power transistor is shunted by the first diode 4 of the reverse current.

The first resistor 5 determines the maximum current at which the switch closes, determines the level of protection current of the switch. Through the first dividing diode 6, the second 7 and third 8 resistors of the base circuit of the additional transistor 3 are connected to the collector of the auxiliary transistor 2.

In the base circuit of the auxiliary transistor 2, there is a fourth resistor 9, which connects it with the collector circuit of the auxiliary transistor, containing the fifth resistor 10. The source 11 of the input two-pole pulsed voltage produces pulses of different polarity. The second 12 and third 13 reverse diodes create a circuit for passing current from a pulsed source. The low-voltage source 14 and the entire circuit it feeds are protected from the high voltage of the key by the second isolation diode 15.

The scheme works as follows

The input signal from source 11 acts on the bases of transistors 2 and 3 (Fig. 1). The polarity refers to the open state of the power transistor 1.

In this case, the current flows through the circuit: source of 11 pulses, diode 13, emitter-base of transistor 2, minus source of 11 pulses. The transistor 2 is in the open and 3 in the closed state, the trigger pair 2-1 keeps the transistor 1 in the open state when the pulse from the source 11 ends.

Upon receipt of a reverse polarity 1 pulse from the source 11 transistor

3 opens, which leads to the locking of transistors 2 and 1. This state is fixed by a trigger pair of 2-3 and does not depend on the magnitude of the voltage on the closed transistor 1.

In the open state of transistor 1, transistor 2 is also open, and transistor 3 is closed. As the key current increases, the voltage on it starts to increase, which leads to a decrease in the base current of transistor 2. With a certain voltage on the key, the saturation coefficient of transistor 2 becomes equal to one and the base current of transistor 1 begins to fall, which increases the voltage drop across it, and this leads to a further decrease in the base current of transistor 2

. Trigger 2-1 capsizes, i.e. the transistors 1-2 are switched to the closed state, and the transistor 3 is opened.

In this process, transistor 3 accelerates the process of shunting the base current of transistor 2.

Transistor 2 has a collector load separated by diode 6 (resistors 5 and 8). At the same time, the current from the pioneering transistor 3 flows, and the base circuit of the power transistor 1 flows. This prevents the opening of the power transistor 1.

Claims (1)

Invention Formula A power transistor switch containing a trigger pair on transistors of different types of conductivity, one of which is power and the other an auxiliary, first and second terminals of a low-voltage power source, first and second terminals of an input two-pole pulse voltage source, first and second resistors, first and second delimiter 11th diodes, the first reverse current diode, output terminal, the emitter of the power transistor is connected to the second terminal of the low-voltage power source and to the anode of the first reverse current diode, the cathode of which is connected to the collector of the power transistor and to the cathode of the second isolation diode, characterized in that application areas, an additional transistor of the same conductivity as the auxiliary, second and third reverse current diodes, the third, fourth and fifth resistors, the first pin of the first resistor is connected li ne first separator to the anode of the diode and to the collector of the auxiliary transistor, the emitter of which is connected to the emitter of the additional transistor and the first terminal of the low voltage power source, the second terminal of the first resistor connected to the base of the power transistor, the collector koto- connected to the output terminal, the first output of the second resistor is connected to the cathode of the first isolation diode and the first output of the third resistor, the second output of which is connected to the second terminal of the low-voltage power supply, the second output of the second resistor is connected to the base of the additional transistor - polar pulse voltage, the first terminal of which is connected to the base of the auxiliary transistor and to the first terminal of the fourth resistor, the second terminal of which is connected to To the collector of the additional transistor and to the first output of the first resistor, the second output of which is connected to the anode of the second separation diode, the base-emitter junctions of the auxiliary and additional transistors are shunted by the second and third reverse current diodes. / vv / T / vy one Compiled by A. Tsekhanovsky Editor G. Volkova Tehred M. Didykkorrektor I. Muska Order 7965/55 Circulation 884 VNSH-SHI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab., A / 5 FIG. 2 Subscription