SU1550614A1 - Reversing current switch for control of inductive load - Google Patents

Abstract

The invention relates to a pulse technique and can be used in various electrical and electronic devices. The purpose of the invention is to increase the speed of a reversible current switch for controlling inductive load by eliminating the inductive load from pulling down the output transistors of the bridge circuit. When the control voltage is removed from the bus 28, the transistor 13 closes, which breaks the base current of the keys 2 and 3. The key 2 and the transistor 9 are closed. The transistors 10 and 22 are turned on, because form a transistor analogue of the thyristor, which is maintained in the on state for the time of closing the current of self-induction of inductive load 25. 1 sludge.

Description

The invention relates to a pulse technique and can be used in various electrical and radio electronic devices, in particular, for reversing control of inductive loads, for example, polarized relays and direct current motors.

The purpose of the invention is to increase the speed of a reversible current switch for controlling inductive load by eliminating the load inductance of the switching off process of the output transistors of the bridge circuit.

The drawing shows a circuit diagram of the proposed reversible current switch for controlling inductive load.

The switch contains a bridge circuit on four transistor switches 1-4, which are made composite on transistors 5-12 of different conduction types, the first and second control transistors 13 and 14, four resistors 15-18, two diodes 19 and 20s, the first 21 and the second 22 additional transistors, pins 23 and 24 for connecting inductive load 25, power supply bus 26, common bus 27,

the first and second control buses 28 and 29, the first and second additional diodes 30 and 31 included in the collector circuit of the transistors 10 and 12.

The pins of one of the diagonals of the bridge circuit are connected to pins 23 and 24 for connecting inductive load 25, the pins of the other diagonal are connected to the power bus 26 and the common bus 27. The bases of the first and second control transistors 13 and 14 are connected to the first through resistors 15 and 16 and the second control buses 28 and 29, and the collectors are directly connected to resistors 18 and 17 and emitters directly to the bases of the respective transistor switches 2, 3 and 1, 4 of the opposite shoulders of the bridge circuit.

The emitters of the first and second additional transistors 21 and 22 are connected to the bases of the first and second control transistors 13 and 14, respectively, and through diodes 19 and 20 to the terminals 23 and 24 of the load, collectors to the bases of the second 2 and first 1 transistors 2 and 1, and the bases are connected to the common bus 27.

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A reverse current switch for controlling an inductive load operates as follows.

When a control voltage is applied to the first control bus 28, the first control transistor 13 is opened, which in turn opens the transistor switches 2 and 3 by passing their base current. Through the open transistor switches 2 and 3, according to the load 25, a current begins to flow in the direction from the pin 23 to the output 24.

When the control voltage is removed from the first control bus 28, the first control transistor 13 closes, which interrupts the base current of the transistor switches 2 and 3. The transistor switch 2 and the input transistor 9 of the composite transistor switch 3 are closed. Close the output transistor 10 of the composite transistor switch 3 does not occur, because when the transistor switch 2 is closed, breaking the power supply circuit of the inductive load 25, a self-induction voltage of the inductive load 25 arises, which opens the first through the diode 20 A transistor 22 which, by connecting the base through the first additional diode 30 and the collector through the base collector junction of the input transistor 5 of the composite transistor switch 1, respectively, to the collector and the base of the output transistor 10, maintains the transistor analogue of the thyristor with the latter, for closing current self-induction inductive load 25.

Thus, when the control voltage is removed, the inductive load circuit 25 is shorted through a diode 20 by a transistor analogue of a thyristor formed by the first auxiliary transistor 22 and the output transistor 10 of the composite transistor switch 3.

The operation of the switch when applying and relieving the control voltage to the second control bus 29 is similar.

The speed of a reverse current switch for controlling inductive load is higher than that known by eliminating the inductance of the load by deactivating the process of switching the output transistors of the bridge circuit.

Claims (1)

Claims of the invention A reverse current switch for controlling inductive load, containing a bridge circuit on four transistor switches, which are made composite on transistors of different conduction types, the outputs of one diagonal of the bridge circuit are connected to the power bus and the common bus, and the conclusions of the other diagonal are connected to the terminals inductive load, the first and second control transistors, the bases of which are connected respectively to the first and second control buses, and the collectors and emitters - to the bases of transistor keys of opposite shoulders of the bridge circuit, two the diode, the first and second additional transistors, the emitters of which are connected to the bases of the first and second control transistors and the turn of the diodes - with the terminals connecting the load, and the base - with a common bus, different with the fact that, in order to improve speed, two additional diodes, the collectors of the first and second additional transistors connected to the bases of the transistor switches, which are connected to the collectors of the first and second control transistors, respectively, the collector of each output transducer Anisistor other transistor switches through the corresponding additional diode connected to the common bus.