SU1497735A1 - Transistor switch - Google Patents

Abstract

The invention relates to a pulse technique. The purpose of the invention is to increase the reliability of work. To do this, the device has two circuits: for unlocking the transistor 1, first through the 6.8 RC circuit, then through the 5.4 resistors

for locking in case of overload on the output bus 10 via the feedback element 7 and the transistor 2. The signal on the presence of an overload is removed from the current-to-voltage converter 3. 1 il.

Description

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The invention relates to a pulse technique and can be used in various switching devices where protection of the SILOR transistor from overload currents is required.

The purpose of the invention is to increase the reliability of the transistor switch.

The drawing shows the electrical key diagram.

The transistor switch contains first 1 and second 2 transistors, a current-to-voltage converter 3, three resistors 4-6, a feedback element 7, a capacitor 8, a control bus 9, an output bus 1 O, and a common bus 11, but the base of the transistor 1 through a resistor 4 is connected to the collector of transistor 2 and through a capacitor 8 to the first output of resistor 6, the second output of which is connected to the control bus 9 and through a resistor 5 to the collector of transistor 2, the base of which is connected to the output bus 10, which through the converter 3 tons k - voltage is connected to the collector of the transistor 1 whose emitter and the emitter of transistor 2 connected to ob- conductive bus 11.

Transistor key works as follows.

In the initial state, a low voltage level is applied to the control bus 9, while the transistor 1 is in the closed state and the transistor 2 is in the open state. When a high voltage is applied to the control bus 9, transistor 1 is opened through resistor b and capacitor 8. For a cToHJiHa-i, the time of this circuit is enough to open transistor 1. As the transistor 1 turns 1, the transistor 2 closes due to - the current of its base, caused by a decrease in the voltage on the output bus 10, which ensures the flow of the base current of the transistor) from the control bus 9 through the resistors 4 and 5.

When an overcurrent occurs, the current-to-voltage converter 3 generates a high voltage level, without delay the opening transistor 2 through feedback element 7. In this case, transistor 1 closes As a reverse element

The connection may be an Isolta} resistor.

After elimination of malfunctions in the tension, the opening of the transistor 1 occurs when applying a voltage drop to the control spike 9 from a low voltage to a high level.

The proposed key allows to increase the reliability of operation by reducing the pulsed power dissipation on the first transistor 1, due to the reduction of the closing time of the first transistor 1 in the emergency mode, since (unlike the prototype) opening of the transistor 1 when the high voltage on the control bus 9 is provided by flowing the current C11 of the circuit through the circuit consisting of the resistor 6 and the capacitor 8, and then (as the transistor 1 is opened and the transistor 2 is closed) through the circuit consisting of A tori and 5; in emergency mode, the flashing of transistor 1 occurs along a circuit consisting of feedback element 7, transistor 2, the latter circuit not contributing to the transmission of the signal from the output bus 10.

Claims (1)

Invention Formula A transistor switch containing the first and second transistors, the current-voltage converter, the first and second resistors, the capacitor, the power transistors of the first transistor are connected in series with the current-voltage converter and connected between the output bus of the device and the common bus, the collector of the second transistor is connected to the first the output of the first resistor, and the emitter - with a common bus, characterized by the fact that, in order to increase the reliability of operation, a feedback element and a third resistor are introduced, the base of the first transistor is connected second vsho- house the first resistor and the first terminal of the capacitor, the second terminal of which is connected via a second resistor to the control bus, which is connected via a third resistor to the collector of the second transistor, whose base via the feedback element is connected to the output bus.