SU1525691A1 - Dc voltage stabilizer - Google Patents

Abstract

The invention relates to electrical engineering and can be used in voltage stabilization and control devices. The purpose of the invention is to increase reliability and enhance functionality. For this purpose, a current generator on the bipolar transistor 15 and the voltage level adjuster on the variable resistor 16 are introduced. As the output voltage increases or decreases, the resistance of the transistor 15 increases or decreases, respectively. Thus, the voltage across the resistor 16 is constant. provides a constant control voltage at the base-emitter junction of transistors 12,13. An increase in the emitter current at transistor 12 causes an increase in voltage on the current-carrying resistor 14 and, when equal to the voltage at the output of resistor 16, causes the transistors 12, 13 to be locked and a flowing current to be smoothly limited. By varying the voltage from the output of the resistor 16, the threshold of the current protection can be varied by adjusting it over a wide range. 1 il.

Description

The invention relates to electrical engineering and can be used in voltage stabilization and control devices.

The purpose of the invention is to improve the range and expansion of functional capabilities.

The drawing shows a schematic diagram of a voltage regulator.

The stabilizer contains a diode-thyristor bridge on power diodes 1 and 2 and thyristors 3-8, connected between the taps of the power transformer 9 and the input terminal 10, the input terminal 11 is connected to the extreme terminal of the transformer 9, the current limiting element on the transistors 12 and 13, the current-providing 1 resistor 14, the current generator on the bipolar transistor 15 and the voltage level adjuster on the variable resistor 16, the current limiting element being included in the diagonal of the direct current of the diode-thyristor bridge, the driving circuit consisting of after connected resistor 17 and condenser 18, shunting zener diode 19, toggle switch 20 and high voltage outputs 21 d 22.

, I The device operates as follows l | a3OM.

After powering on pins 10

21 and 22, 11 to perform a smooth start-up of the device, they close 1: toggle switch 20 contacts. At the same time, the capacitor 18 is charged through the resistor 17 of the master circuit until it is stabilized by the Zener diode 19. As the capacitor charges 18 With a positive potential applied, lie to the bipolar-to-transistor 15 base-emitter junction, it opens and a current lio of the circuit begins to flow: output terminal 21 (positive polarity of applied applied voltage) —bipole transistor 15 — variable variable resistor 16 — output ex 22 (negative for the applied DC voltage). The increasing control voltage from the output of the resistor 16 is energized to the base-emitter junction of the composite transistor 12 and 3, as a result of which it is smoothly pulled off to the full. Such device activation allows exclusion

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five -

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to determine the magnetizing current, the device starting time being determined by the parameters of the time of the driving RC circuit 17 and 18 and the stabilization voltage of the zener diode 19.

Assume that the voltage on output pins 21 and 22 has increased. Of condition

and ,, and ,, - and, 5 „,,

where U- is the voltage drop across resistor 16;

. - stabilization voltage 19; and .-, - base-emitter voltage

ET15

of the bipolar transistor 15, and const it follows that this is necessarily accompanied by a decrease in the voltage between the emitter and the base of the bipolar transistor 15 and a drop in its base current. When the base current drops, the resistance of the bipolar transistor 15 increases, resulting in a voltage UB (J remains almost constant. When the voltage decreases at the output terminals 21 and 22, the resistance of the bipolar transistor 15 decreases, the current through it increases Thus, the voltage of the resistor 16 is constant, which ensures the stability of the control voltage at the base-emitter junction of the composite transistor 12 and 13. An increase in the emitter current through the transistor 12 increases the voltage on the current-carrying resistor 14 and at a value equal to the voltage at the output of the resistor 16, causes the locking of the transistors 12 and 13 and smoothly limiting the flow of current.This change in the voltage value from the output of the resistor 16, you can change the threshold current protection is activated by adjusting it over a wide range.

 When the device is turned off, the previously charged capacitor 18 is discharged through the base-emitter junction of the bipolar transistor 15 and the resistor 16.

Thus, the introduction of a current generator at a bipolar transistor and a voltage level sensor allows to simplify the device and increase the reliability of its operation regardless of the change in the value of the DC voltage at the output terminals of the device. At the same time, the operative adjustment of the threshold of operation of the current-limiting element enhances the functionality of the device and increases the effectiveness of protection during current overloads in the load.

Claims (1)

Claims of the invention A constant voltage regulator connected to a resistor and a capacitor shunted by a zener diode, and output pins, one of which is connected to the diode of the thyristor bridge, characterized in that, in order to increase reliability and expand functional capabilities, .ne containing a power transformer with a sectioned winding, a diode bridge connected between the transformer taps and one of the input terminals, the other input terminal is connected to the extreme terminal of the power transformer, the current-limiting element included in the diagonal of the current bridge of the specified bridge, made on a composite transistor and current supply a resistor, the emitter of the composite transistor is connected through a current-setting resistor to the diode of the thyristor bridge, and the collector to the anode directly. - We rip the master circuit consisting of Consequently, a connected resistor and a capacitor bounded by a zener diode and output pins, one of which is connected to the anode of the diode-thyristor bridge, characterized in that, in order to increase reliability and expand functionality, a generator is inserted into the current limiting element. -15 -- 25 current, made on a bipolar transistor, and a voltage level adjuster, the emitter of a bipolar transistor connected to the anode of a diode-thyristor bridge through the voltage level adjuster, the collector to another output terminal, the base is connected to the connection point of the resistor and capacitor the master circuit, the second pin of the resistor of this circuit is connected to the collector of the bipolar transistor, and the second capacitor lead to the anode of the thyristor bridge, and the output of the voltage level setter is connected to the base of the composite transistor ora