SU1051716A1 - Semiconductor switch - Google Patents

Abstract

A SEMICONDUCTOR KEY, containing a composite transistor and a solid one on two trazists, the base of which includes the first one. diode, and to the point of connection of collectors EUdkeye} the first output of the second diode and the output terminal; the base of the composite transtrans, and KonneKTqpfj to the first terminal of the respective voltage sources. At the same time, the second KneiMtMa.oflHoro from the notochnikov and the emitter of the composite transistor Tqpa are connected to the common bus from l and tea and the second diode, which is connected to the second terminal of the same diode, is introduced to the second (L terminal Another source of jagfaokeni and an emitter of a composite transistor.

Description

The invention relates to a pulse technique and can be used as a power switch in a conversion device for various purposes. Known semiconductor key containing transistors, two diodes, the co-limiting resistor, the input and output terminals YJ. The disadvantages of the well-known key & are low speed when switching on and large size and weight due to the presence of reactive elements (transformer and capacitor). Also known is a semiconductor switch containing a composite transistor, implemented on two transistors, between the bases of which the first diode is connected, and the first terminal of the second diode and the output terminal, power amplifier, of the first and second transients TqpOB of different conductivity, the bases of which are connected connected to the input terminal, the emitters through the current-limiting resistor to the base of the composite transistor, and the collectors to the first terminals of the corresponding voltage sources, while at the same time o from the sources and emitter of the composite transistor are connected to the common bus 2j. However, the disadvantage of this switch is also $ 1, which results in a slow response rate due to a decrease in the decay rate of the collector current of the output transistor after locking the emitter junction due to passive resorption of excess media in the collector region. The purpose of the invention is to increase the fast operation. The goal is achieved by the fact that a semiconductor switch containing a composite transistor made on two transistors, between the bases of which the first aiop is connected, and the first terminal of the second diode and the output are connected to the junction point of the collectors consisting of the first and transistor tori of different conductivity, the bases of which are connected to the input terminal, the emitters through the current limiting resistor to the base of the composite transistor, and the collectors to the first terminals of the cooTBeTCTByKv their voltage sources, while the second terminal of one of the sources and the emitter of the composite transistor are connected to a common bus, a third diode is inserted (the cathode is connected to the second terminal of the second diode of the same name, the second terminal of another voltage source, and the composite transistor emitter. FIG. Fig. 1 shows the electrical circuit of the key driver; Fig. 2 shows the time diagrams of voltages and currents (the transition line in the prototype is shown by comparison line). The semiconductor key contains a composite transistor 1, made on two transistors 2 and 3 ,. For example, the PN conductivity of the midfield bases of which are connected to the first diode 4, and the cathode of the second diode 5, the power amplifier 6, CONTAINING from the first transis- sion, is connected to the junction point of the collectors. Tqpa 7 n conduction and the second transistor 8 pnp conductivity. The bases of transistors 7 and 8 are connected to the input terminal & emitters via TB co-limiting resistor iO to the base of the composite transistor 1, and the collectors to the positive terminal 11 of the unlocking and the negative terminal 12 of the locking voltage sources, while the minus terminal of the unlocking source the voltage and the emitter of the composite transistor 1 are connected to the common bus 13. The anode of the third diode 14 is connected to the anode of the second diode 5 and the positive terminal 15 of the blocking voltage source, and the cathode to the emitter of the corresponding transistor 1, whose collector dinen with output terminal 16. Semiconductor key works as follows. At the moment when the polarity of the signal at the input terminal 9 changes from positive to negative (the beginning of the switching off process), transistor 7 closes, transistor 8 opens and current flows from circuit voltage source through terminal 15 - diode 5 - junction-collector transistor 2 - resistor 1O - the emitter-collector circuit of transistor 8 - terminal 12. At the same time, excess noytels in the collector region of transistor 2 actively dissolve and its base-collector voltage increases (transistor 2 goes out of the saturation region). After this, the current from the blocking voltage source begins to flow through the circuit terminal 15 - diode 5 - base-collector junction of transistor 3 - parallel transSHcrqpa 2 base-emitter junction and diode 4 - resistor 10 pept emitt-e collector of transistor 8 terminal 12. In this case, excessive carriers are actively absorbed in the collector region of the power transistor 3, and transistor 2 is actively locked. Such a state is maintained in the circuit until those nopi until the excess but CHxefoi in the collective region of the transistor 3 are resolved and the collector-emitter voltage on it does not increase so much that diode 5 is closed. After that, the current From the blocking voltage source flows through the circuit terminal 15 - diode 14 junction base-emitter of the power transiotor 3 - diode 4 (junction base-emitter of transistor 2 is already locked at this moment) - resistor 10 - emitter-collector circuit of transistor 8 - terminal 12.

In the case of using a composite transistor on p-W transistors, the polarity of the voltage sources and the polarity of switching on the diodes, as well as the conductivity of the transistors of the power amplifier, are reversed.

In the particular case with a small output power, a composite transistor with a diode connected between the bases of the transistors on which the composite transistor is made can be replaced with a single medium power transistor.

In order for the key to work effectively, the direct voltage of diode 5 is less than the direct voltage of diode 14; therefore, it is possible to use a diode 5 in series as a diode 14 or select diodes 5 and 14 with different straight lines. right & mi.

Thus, the use of the proposed semiconductor key makes it possible to reduce the switching of the output transistor to 3-4 microseconds and increase the efficiency to 95%.

This greatly simplifies the circuitry of the device (the peaks of protection from through currents, the formation of safe switching paths of the output transistor are simplified), and cost-effectiveness and reliability are improved.

tH

inc

phage 2

Claims (1)

SEMICONDUCTOR KEY containing a composite transistor made on two transistors between the bases of which the first diode is connected, and the first output of the second diode and the output terminal, a power amplifier consisting of the first and second transistors of different conductivity, the bases of which are connected to input terminal, emitters through current-limiting re; the resistor is to the base of the composite transistor, and the collectors are to the first terminals of the corresponding voltage sources, while the second ¹ terminal of one of the sources and the emitter of the composite transistor are connected to a common bus, which is based on the fact that, in order to * To improve performance, a third diode is introduced, which is connected to the same name. <the second terminal of the second diode, the second terminal of another voltage source and the emitter of the composite transistor. J, „. 1051716 105171 "