SU1372311A1 - D.c.voltage stabilizer - Google Patents

Abstract

The invention relates to electrical engineering, in particular, to DC voltage stabilizers, and can be used to power electronic equipment. The purpose of the invention is to increase the reliability of the stabilizer - a constant voltage by increasing the sensitivity of the protection unit. This is achieved by introducing a load current sensor 11 connected to the second stabilizer supply bus, and performing the time of the master stage 9 as a single-stable multivibrator on transistors 12 and 13, a capacitor 14 with the transistor 15 additionally turned on. cascade 9 starts impulses at certain time intervals, opening the control transistor. 1 il. c (o

Description

The invention relates to electrical engineering, in particular, to DC voltage stabilizers, and can be used to power electronic equipment.

The purpose of the invention is to increase the reliability of the constant voltage stabilizer.

The drawing shows a schematic diagram of the proposed stabilizer,

The stabilizer contains a regulating element 1, made in the form of a transistor, connected in series to the power bus of the stabilizer, its input is connected to the output of control unit 2, containing a comparison circuit made on transistor 1, whose emitter circuit includes a source of reference voltage on Zener diode 4 and the resistor 5, the base of the connection of the gene to the middle output of the output voltage divider 6, and the collector - to the collector load resistor 7, and to the base of the regulating element, the output of which is connected to the first input of the control unit The second input of which is connected to the output of the block 8, consisting of the time of the master stage 9 and the threshold element 10, to the input of which the load current sensor 11 connected to the second stabilizer bus is connected. The time master stage consists of a single-stable multivibrator transistors 12 and 13 and a capacitor 14, which is connected to the collector of transistor 13 and the base of the key transistor 15, the emitter of which is connected to the cathode of the Zener diode 16 and through the resistor 17 of the spring voltage source - to the multivibra power bus ora. To shared bus

connect through resistor 18 load with

ki collector transistor: and the anode of the Zener diode 16.

The principle of voltage Zener diode is as follows.

At load currents not exceeding the rated value, the control unit 2 introduces the regulating element 1 into the mode providing the rated voltage at the output of the stabilizer.

Under these conditions, the transistor 13 of the time of the master stage 9 of the block 8 is protected: closed, and the transistor 12 is open and the premier of the capacitor 14 is on

d

p 5 about

five

0

five

five

0

is in the charged state. The potential of the key transistor 15, determined by the magnitude of the voltage on the Zener diode 16, is slightly lower than the voltage on the power busses of the multivibrator, which ensures the closed state of the key transistor 15 and the absence of voltage on the resistor 18.

When the load current exceeds its rated value, the voltage across the current sensor 11 resistor, which enters the input of the threshold element 10, increases, the threshold element switches and applies the voltage of the master stage 9 to the base of transistor 13, converting it to an open state than The sensitivity of the protection unit is high at low overloads. At the same time, transistor 12 closes, discharge time of master capacitor 14 begins, and transistor 15 switches to open state. The voltage applied to the resistor 18 is controlling for the control unit 2 and the regulating element 1 is closed, the voltage on the load becomes zero.

After the time of discharge of the capacitor 14, the transistor 13 opens, the transistor 12 closes and the capacitor starts charging. When the voltage across the capacitor of the transistor 12 reaches a value close to the voltage of the emitter of the transistor 15, the transistor closes, the actuator removes the signal from the protection input of the control unit and the control element turns on, setting the load to the nominal voltage.

If there is an overload or repetition of the short circuit mode, the operation process of the protection unit is repeated, and the reclosing time is practically determined by the sum of the discharge times and the charging time of the setting capacitor 14, which do not depend on the mode of operation of the stabilizer.

The proposed stabilizer ensures the protection performance achieved by automatic restarting after a specified period of time, which predetermines the wide possibilities of its use in electronic equipment.

Claims (1)

Invention Formula A constant voltage stabilizer containing a regulating element connected in series to the power bus, the input of which is connected to the output, and the output - to the first input of the control unit, the second input of which is connected to the output of the protection unit consisting of a series-connected threshold element cascade, the output of which is the output of the protection unit, which is characterized by the fact that, in order to increase reliability, a current sensor is inserted into it, which is included in common busbar, the middle output of which is connected to the input of the threshold element, and the time setting cascade of the protection unit is made on a single-stable multivibrator, a key transistor, a zener diode and two resistors, the collector of the first transistor of the multivibrator through the first resistor - with an adapter for connecting the power supply of the multivibrator, and the collector of the key transistor through the second resistor and the anode of the Zener diode is connected to bus tire.