SU864272A1 - Dc voltage stabilizer - Google Patents

Description

(54) DC VOLTAGE STABILIZER

I

The invention relates to electrical engineering and can be used to power an electronic device.

. Known constant voltage regulators, current-with overload protection and short circuit. 1.1

The closest in technical essence and achievable result to the proposed is a voltage and direct current stabilizer containing a regulating node connected by a collector and an emitter to the first input and output pins of the stabilizer, measuring and amplifying node whose output is connected to the base of the regulating transistor ,, and the input is connected to the output pins of the stabilizer, the protection node consisting of a current detector connected between the second input and output OUT of the stabilizer, resistive divider, on between the second input and the first output pins of the stabilizer, the DC amplifier, the input connected between the resistive divider output and the second output pins of the stabilizer / and the output of the regulator of the bias resistor regulating transistor, the single pin of the stabilizer connected to the first input pin of the stabilizer t 3 This device is impacted by a low e (i) effectiveness of the overload protection of the stabilizer, consisting in the low sensitivity of the protection node to the change in resistance no load.

1 $

The purpose of the invention is to increase the effectiveness of the protection of the stabilizer against overcurrent.

Claims (1)

The goal is achieved by the fact that, in a known DC regulator, the DC amplifier of the protection node is made of two transistors with conductivity similar to the regulating transistor, and the base and emitter of the first transistor form the aforementioned amplifier input, the collector and the emitter of the second transistor form the amplifier output and shunt the base-emitter junction of the control transistor, and the collector of the first transistor is connected to the base of the second transistor and the second output of the bias resistor. To start the stabilizer, a switch, a capacitor and a resistor, are additionally introduced into it. at the same time, the closing contact of the switch is connected to the collector of the first protection transistor, and the opening and switching contacts, respectively, are connected via a resistor and a capacitor to the second output of the stabilizer. The drawing shows a circuit diagram of a DC voltage regulator. The device contains a sequential regulating node of a transistor 1-3 connected to the positive power supply bus, a measuring amplifier section consisting of resistors 4-12, transistors 13-19 and a zener diode 20 connected to the output of the stabilizer, and the output to the base of the transistor 3 control unit, current sensor 21, connected to the negative power bus, voltage divider 22 in the form of a potentiometer, connected between the positive output and negative input terminals of the stabilizer, the first 23 and second 24 protection transistors, resis Op offset 25, trigger circuit stabilizer consisting push button switch 26 and a momentary, start capacitor 27 and the discharge resistor 28, vy lane 29 and a second input 30 and first 31 and second 32 output terminals. The device works as follows. In normal operation, the transistor, protection 23 is open, because the voltage at the output of the potentiometer 22 is higher than the blocking voltage on the current sensor 21. The second protection resistor 24 is closed, because the collector voltage of the transistor 23 with load 25 is less than the output voltage and the base-emitter junction of the transistor 24 is a locking voltage. In the overload mode, when the load resistance becomes less than the threshold value, the voltage drop across the current sensor 21 reaches such a value that the transistor 23 goes out of the down mode to the gain mode, the voltage drop on its collector increases. As soon as the output voltage of the stabilizer is higher, it opens; protection transistor 24 and reduces the control current of the regulating node. As a result, the load current decreases, the output voltage unlocking the voltage of the transistor 23, which begins to pass into the cut-off region, and the transistor 27 - into the open region, completely shunt the control transitions of the regulating node. Thus, an avalanche-like process of locking the stabilizer occurs. To return the stabilizer to working condition, overload elimination is necessary with the help of over-. switch 26, the discharged capacitor 27 is connected to the collector of protection transistor 23. At first, capacitor 27 short circuits the collector-emitter transition of transistor 23, which causes the transistor 24 to close, which ceases to affect the operation of the regulating node and ensures the stabilizer returns to working condition. Resistor 28 is required to discharge the starting capacitor 2 / after self-resetting switch 26. The proposed invention reveals the sensitivity of the stabilizer protection to overloads and thereby increases its effectiveness. Claims. A DC voltage regulator containing a regulating node, connected by a collector and an emitter to the first input and output pins of the stabilizer, a measuring and amplifying node whose output is connected to the base of the regulating transistor, and the input is connected to the output of the stabilizer. the current sensor connected between the second input and output pins of the stabilizer, resistive depot, connected between