SU943676A1 - Protected dc voltage stabilizer - Google Patents

Description

(5) CONSTANT VOLTAGE STABILIZER WITH PROTECTION

one

This invention relates to electrical engineering; in particular, to integral voltage stabilizers, and can be used as a secondary power source for automation and computer technology.

A voltage regulator is known, comprising a control transistor, a supporting element, a device for comparing output and reference voltages, a control transistor, resistors of the collector load of the control transistor, a transistor, a protection and a capacitor, a shunt control transdistor

The closest to the technical essence of the invention is a DC voltage regulator with protection comprising a control element connected in series with a resistive current sensor 20 to the power bus with a field-effect transistor in the control circuit, a differential feedback amplifier, one input of which is connected midpoint divider output voltage,. and the other input is with a reference voltage source, a resistor-diode voltage sensor, a threshold transistor, and a current-stabilizing transistor (2j.

The disadvantages of the stabilizer are the low input resistance of the regulating element, its dependence on the load resistance of the stabilizer, which significantly reduces the stabilization factor and increases the output resistance of the stabilizer.

The aim of the invention is to improve the reliability of the stabilizer with a field effect transistor at the input of the regulating element.

The goal is achieved by introducing into the stabilizer an actuating protection transistor, an emitter connected to the emitter of the threshold transistor, a base to the collector of the threshold transistor, and a collector with the drain of the aforementioned field transistor 33 36764

the additional diode, the cathode, the collector current of the actuator connected to the output of the differential transistor 10, is the current of the amplifier protection transistor, base with midpoint output voltage divider.

The drawing shows a voltage regulator circuit.

 The voltage stabilizer contains a current sensor 1 connected to the collector of the power transistor 2 of the regulating element 3- A field-effect transistor is connected at the input of the regulating element. The resistor-diode voltage sensor 5 is connected to the current sensor 1 and the collector of the power transistor 2 by one output, the other to the output terminal. The differential feedback amplifier 6 is connected via an inverting input to an output voltage divider 7, and non-inverting to a voltage source 8. The threshold transistor 9 is connected by an emitter to a current sensor 1, an emitter of an executive transistor 10, and an input bus. The diode 11 is connected by an anode to the gate of transistor 4, and a cathode to the output of an amplifier. A current stabilizing transistor 12, the emitter of which is connected through a current-supplying resistor 13 to a common bus, a collector to the base of the executive and a collector of the threshold transistors, and the base to a voltage divider. The collector of the Executive transistor 10 is connected to the drain of the transistor .. The stabilizer operates as follows. 8, the operating mode of the transistor 10 is in the saturation mode, which is provided by the current generator on the transistor 12, and the transistor 9 is closed. The current through the transistor 10 and in series with it the switched on transistor 4 is determined by the load current and the current gain factor of transistor 2. then the voltage drop across the resistive current sensor increases, the threshold protection transistor 9 opens and shunts the base-emitter junction of the protection protection transistor 10, its base current decreases, it starts AET close. As a result of the field-effect transistor of the regulating element, and hence the basic

Claims (1)

the current of the power control transistor 2 decreases, and it begins to close. The voltage drop across the regulating element increases, the output voltage decreases. In this connection, the bias voltage of the current stabilizing transistor 12 decreases, which leads to a decrease in the response time of the protection and an increase in the slope of the characteristic of the protection circuit. The output voltage decreases until the voltage at the junction of the collector-emitter of the power transistor 2 of the regulating element 3 reaches the magnitude of the trigger voltage of the zener diode in the diode-resistor voltage sensor 5, the current flowing through the sensor 5 creates an additional bias unlocking the transistor 9, which leads to the locking of the transistor 10 and the complete cutoff of the drain current of the field-effect transistor and the locking of the power transistor 2 of the regulating element 3, thus, is carried out by the regulating transistor e only from overcurrent but also ° voltage and power. In the short circuit mode, transistors 9, Yu and 12 are closed. The diode 11 prevents the occurrence of a forward gate-to-source transition current of the field-effect transistor. When the overload is removed or the fault is eliminated, the output voltage is restored, the stabilizer returns to normal operating mode. The above protection scheme makes it possible to significantly increase the operational reliability of the voltage regulator without compromising the stability of the output voltage when the load, supply voltage, and temperature changes. Claims of a Direct-Voltage Stabilizer with Protection Containing a control element connected in series with a resistive current sensor to a power bus with a field-effect transistor in the control circuit, a differential feedback amplifier, one input of which