SU1171769A1 - D.c.voltage stabilizer - Google Patents

Abstract

CONSTANT VOLTAGE STABILATOR, containing a regulating transistor connected to the output terminal of the first power, second to the first output of the current sensor, second power to the diode cathode and the output of the feedback amplifier connected to the output voltage of the reference voltage source and average divider voltage. connected by the inputs between the output terminal and the common bus, the thyristor connected by the cathode to the diode anode, to the first supply output of the feedback amplifier and to the first output of the limiting element connected by the second output to the input terminal, to the second output of the current sensor and to the first output of the resistor, connected by the second output to the control electrode of the thyristor and to the first base of the unijunction transistor connected to the common base by the second base, to the thyristor anode and to the second supply output of the feedback amplifier, and em itter to the first output of the sensor (L ka current, characterized in that, in order to reduce power consumption when the protection is turned on, the limiting element is made on an adjustable L-diode.

Description

-about

USMf.

The invention relates to electrical engineering and can be used in various power supply devices for electronic equipment.

The purpose of the invention is to reduce the required power when protection is turned on.

FIG. 1 is a diagram of a stabilizer with a higher setting accuracy; the threshold of protection operation; figure 2 - adjustable diode on discrete elements; on fig.Z its characteristics.

The DC voltage regulator (Fig. 1) comprises a current sensor 1 connected in series to a power circuit on a resistor, a regulating transistor 2, a feedback amplifier, on an operational amplifier 3, one output of which is connected to a Zener diode voltage source, 4, supplying through a resistor 5, the other to the resistor divider 6 of the output voltage, and the output to the base of the regulating transistor 2, to the connection point of the current sensor 1 with the input voltage through the limiting element 7 is connected Ithel 3, the anode of the diode 8, the cathode of which is connected to the base of the regulating transistor 2 and a cathode of the thyristor 9, the anode of which together with a second supply terminal of the operational amplifier 3 is connected to a common bus stabilizer. The control electrode of the thyristor 9 is connected through an ß-resistor 10 to the input terminal and to the first base of the unijunction transistor 11, the second base of which is connected to the common bus and the emitter to the junction point of the current sensor 1 and the regulating transistor 2.

The device works as follows.

At the rated current in the load circuit, the voltage drop across the current sensor 1 is not enough to turn on the thyristor 9, the diode 8 is biased in the opposite direction, the control transistor 2 is controlled by the feedback amplifier, and the output of the stabilizer has a voltage that is set by the output divider 6 tension

In case of overload or short circuit at the output of the stabilizer, the voltage drop across the current sensor 1 increases, which causes the thyristor 9 to turn on, causing the diode 8 to move in the forward direction. At the same time, the supply voltage of the feedback amplifier 3 switches off, resulting in the base of the control transistor 2 is given a blocking signal and the stabilizer is turned off.

To improve the accuracy of the protection threshold, a single junction transistor 11 is inserted into the circuit. When a current overload occurs, the voltage drop across the current sensor 1 increases, resulting in a positive emitter potential relative to the first base, which leads to the inclusion of a single junction transistor 11, the current through it accordingly, the voltage drop across resistor 10 increases dramatically, which causes the thyristor 9 to turn on and, as in the previous case, to turn off the stabilizer.

Limiting element 7 can be made on resistor 12 (Fig. 2, but when the protection is triggered, almost all input voltage is applied to it (except for the voltage drop on the switched thyristor. 9), as a result, significant power is dissipated on resistor 12. This power is applied as a limiting element to an adjustable 7i-diode 13 (Fig. 2), having a section with negative conductivity.

The working section is chosen in such a way that during normal operation of the stabilizer, taking into account the change in the supply voltage, the current through the 1-diode is maximum and ensures the normal operation of the feedback amplifier 3 on the operational amplifier. When the protection is triggered, the thyristor 9 is turned on and the voltage on the 7l-diode 13 increases dramatically, the current decreases significantly, providing only the minimum holding current of the thyristor 9 in the on state, which leads to a significant reduction in the power dissipated in the circuit: limiting element 7 - Ti diode - thyristor 9.

FIG, g

Fig.Z

Claims (1)

A DC voltage stabilizer containing a control transistor connected by a first power terminal to an output terminal, a second power terminal to a first current sensor terminal, and a base to a diode cathode and a feedback amplifier output connected by inputs to a reference voltage source output and to a middle terminal a voltage divider connected by inputs between the output terminal and the common bus, a thyristor connected by a cathode to the diode anode, to the first supply terminal of the feedback amplifier and to the first terminal of the limiting electric an element connected by a second terminal to an input terminal, to a second terminal of a current sensor and to a first terminal of a resistor connected to a thyristor control electrode and to a first base of a single-junction transistor connected by a second base to a common bus, to a thyristor anode, and to a second power supply terminal of an amplifier feedback, § by the emitter, to the first output of the current sensor, characterized by V in that, in order to reduce the power consumption ζ when the protection is turned on, the limiting element is made on 3 adjustable λ-diodes. Fig!