SU1601611A1 - Overcurrent-protected d.c. voltage stabilizer - Google Patents

Abstract

This invention relates to electrical engineering and can be used in secondary power supply sources. The goal — extending the output voltage control range — is achieved by introducing additional transistors 13 and 14 and resistor 15. In normal mode, transistor 14 is locked and the positive feedback circuit (through resistor 12 to base of protective transistor 7) is open. Therefore, the tripping current of the overload protection does not depend on the voltage on the regulating element 2, which makes it possible to set low voltages at the output. 1 il.

Description

The invention relates to electrical engineering and can be used in secondary power sources

The purpose of the invention is the expansion of the d-j range of regulation of the output voltage o

The drawing shows a diagram of a stabilizer

The stabilizer contains sequentially included in the power bus resistive current sensor 1 and a control element 2 with terminal 3 for connecting auxiliary voltage, a measuring and amplifying unit 4, 15 connected between the output power terminal 5 and the common bus 6, and the output to the control input control element, protective 7 and switching 8 transistors of the same type of conductivity 20, the emitters of which are connected to the input power output 9, and the commutator collector to the auxiliary output of the regulatory element, the generator OR 10 current, connected 25 between the combined base of the switching and collector of the protective transistors and the common bus, the first resistor 11 connected between the base of the protective transistor and the output of the current sensor 30 associated with the control element, the second resistor 12, one of the terminals connected to the output power conclusion, the first 13 and second 14 additional transistors of one type of conductivity and a third resistor 15 connected between the combined collector of the first and the base of the second additional transistors and a common bus, and emitt Gross carrying polar junction 40 of the additional transistor is connected in parallel with the emitter junction of the switching transistor, and the emitter and collector of the second additional transistor - respectively 45 to the base of the protective transistor and the other terminal of the second resistor "

The stabilizer works as follows »f

In normal mode, the voltage drop across the current sensor 1 is small, therefore, the protective 7 and the second additional 1.4 transistors are closed, and the switching 8 and the first additional 13 transistors are open. On auxiliary terminal 3 of the control element 2, the supply voltage from the input power output 9 is supplied. a positive feedback loop (through the second resistor 12) is opened irrespective of the output voltage (at pin 5) _of

The measuring and amplifying unit 4 controls the control element 2 so that the output voltage remains constant

With current overload, the voltage drop across the current sensor 1 increases, which leads to the unlocking of the protective transistor 7 and the first additional transistor 13 being locked. ”The second additional transistor 14, opening, closes the positive feedback circuit.” As a result, the protective transistor 7 saturates and closes the switching transistor 8 ° The voltage from the auxiliary output 3 of the control element 2 is removed, which leads to its complete shutdown ">

After eliminating the overcurrent, the circuit returns to its previous state. ”In this case, the function of the start circuit is performed by the first 11 and second 12 resistors connected in series”

I

Thus, in this stabilizer, the tripping current of the overload protection does not depend on the voltage on the regulating element, which allows you to set low output voltages "

Claims (1)

Claim A DC voltage stabilizer with overcurrent protection, comprising a resistive current sensor sequentially connected to the power bus and a control element with an output for connecting auxiliary voltage, a measuring and amplifying unit connected between the output power output and the common bus, and the output to the control input of the regulating element, protective and switching transistors of the same type of conductivity, the emitters of which are connected to the input power output, and the commutator commutator to the auxiliary at the output of the regulating element, a current generator connected between the combined base of the switching transistor and the collector of the protective transistor and a common bus, and two resistors, the first of which is connected between the base of the protective transistor and the output of the current sensor, and the second one of the outputs is connected to the output power output, o which implies that, in order to expand the range of regulation of the output voltage, two additional transistors of the same conductivity type and a third resistor connected between the combined collectors are introduced into it Orom of the first and the base of the second additional transistors and a common bus, and the emitter The junction transition of the first additional transistor is connected parallel to the emitter junction of the switching <transistor, and the emitter and collector of the second additional transistor respectively to the base of the protective transistor¹a resistor and another output of the second resistor about