SU1511835A2 - Stabilized power source - Google Patents

Abstract

The invention relates to electrical engineering and can be used in the sources of secondary power supply systems of radio engineering, automation and computer technology. The aim of the invention is to increase reliability by providing an automatic shutdown of the device during an overload and malfunction, and extending the functionality by providing electronic switching on and off of the device. To do this, a stabilized power supply containing two transistors 1.2, a power transformer 3 with an output winding 4 and a feedback winding 5, isolating diodes 11, 12, a zener diode 13, a regulating transistor 14, a resistive three-pole divider 15-17, are introduced switching transistor 20, resistive divider voltage 21,22, additional resistor 23 and winding 24 of power transformer 3, rectifier diodes 25,26, the input of which is connected to additional winding 24 of power transformer 3, and the output through additional resistor 23 It is connected to the on control terminal and through a resistive voltage divider 21,22 to the input of the additionally inputted transistor 20, the collector of which is connected to the collectors of power transistors 1.2, the emitter is connected to the input terminal, and the shutdown control terminal is connected to the second terminals of the connecting diodes 11 ,12. 1 il.

Description

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overloading and malfunctioning and expanding functionality by providing electronic power on and off of the device. For this purpose, a stabilized power supply containing two transistors 1, 2, a power transformer 3 with an output winding 4 and a feedback winding 6, isolating diodes 13, 12, a zener diode 13, a regulating transistor 14, a resistive three-pole divider 15- 17 a switching transistor 20, a resistive voltage divider 21, 22, an additional resistor 23 and a winding are introduced

The invention relates to electrical engineering and can be used in the sources of secondary power supply systems of radio engineering, automation and computer technology.

The purpose of the invention is to increase, reliability by providing automatic disconnection of the power source during overload and malfunctions, and expanding the functionality by providing electronic switching on and off of the power source1. ,

The drawing shows a power supply circuit.

The stabilized power supply contains power transistors 1 and 2, a power transformer 3 with an output winding 4, an input winding 3 and a feedback winding 6, one output through the first resistor 7 connected to the base of the first power transistor 1, the other output directly to the base of the second power supply the first transistor 2 and through the second resistor 8 to the collectors of the indicated transistors, the emitters of the power transistors 1 p -2 are connected to the extreme leads of the input winding 5 of the power transformer 3, to the transitions the base emitter POWER transis tori 1 and 2. Optics 9 and 10 are connected, the bases of these transistors are connected to the first terminals of the connecting diodes 11 and 12, the middle output of the input winding 5. The power transformer 3 is connected to one output of the Zener diode 13 and to the negative input

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24 of a power transformer 3, a rectifier on diodes 25, 26, the input of which is connected to the auxiliary winding 24 of the power transformer 3, and the output through an additional resistor 23 is connected to the switching control terminal and through the resistive divider 21, 22 of the voltage

additionally introduced transistor 20, the collector of which is connected to the collectors of power transistors 1, 2, emitter - to the input terminal, and switching off the connecting pin to the second terminals of the connecting diodes II, 12. 1 Il.

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power supply, an additional transistor 14, the collector of which is connected to the second outputs of the

5 diodes 11 and 12, the emitter - to the second output of Zener diode 13, the base - to the midpoint of a three-pole resistive divider on resistors 15-17, the first and second poles of which are connected to the input terminals of the device, the third through additional diodes 18 and 19 are connected with the emitters of transistors 1 and 2, switching transistor 20, resistive voltage divider 2, 22, additional resistor 23, additional winding 24 of power transformer 3, full-wave rectifier (can be bridge) J which consists of diodes 25 and 26,

 the input of which is connected to the auxiliary winding 24 of the power trans-, formatter 3, and the output through an additional resistor 23 is connected to the switching-on control terminal 27 and through a resistive voltage divider 21, 22 to the input of the transistor 20, the collector of which is connected to the collectors of power transistors 1 and 2, an emitter is connected to the input power input, which turns off the control output 21 is connected to

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The second conclusions of the driving diodes are П and 12.

The source works as follows.

In the absence of control signals on the switching-on control output, the additional transistor 20 is closed and in the converter

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missing. The resistor 21 serves to securely lock the transistor. After a low level control signal is applied to the control terminal 27, the transistor 20 through the resistors 22 and 23 is unlocked and the supply voltage goes to the collectors of the power transistors and 2, a generation occurs in the transformer and the voltage in the form of a square wave is transformed to the output side of the winding 4 and the additional winding 24 of the power transformer 3, the alternating voltage of the winding 24 The converter is converted into the rectifier 25i 26 into a constant voltage and through an additional resistive divider 21, 22 is applied to the additional input of the transistor 20, whereby the transistor 20 is maintained in the open state and after the termination of the control signal at the output 27. The output voltage is stabilized by fixing the positive voltage half-periods in the base circuits of the transistors 1 and 2 with the help of the Zener diode 13, additional transistor 14 and dissolving diodes 11 and 12. Negative half-periods of the voltage in the base circuits of transistors 1 and 2 lock the corresponding transistor, while the emitter is back applied The voltage is limited by diodes 9 and 10. Positive voltage half-periods in the emitter circuits of transistors 1 and 2 through additional diodes 18 and 19 go to the third pole of the resistive divider 15-17, to the first pole of which the input voltage goes. The resulting voltage at the midpoint of the bipolar divider is compared through the emitter-base junction of transistor 14 with the breakdown voltage of the zener diode 13 and controls the opening degree of the transistor 14, the resistor 8 serves to increase the reliability of the converter start-up. Resistor 7, depending on the emitter current of transistors 1 and 2, sets the base current for transistors 1 and 2 and the current through Zener diode 13,

When the control signal is applied low to the switching-on output 28, the potential of the bases of transistors 1 and 2 drops rapidly, which leads to the closure of transistors 1 and 2 and the cessation of generation in the converter.

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Due to the interruption of the supply of the unlocking voltage to the base of the switching transistor 20, it closes and stops supplying power to the collectors of the power transistors 1 and 2 and, as a result, to switching on the converter. After turning off the converter, the current consumption of the device is completely absent.

Switching off the converter occurs both in case of overloads in the load and short circuit, when the power transistors change from saturation mode to linear mode.

At the same time, due to the fall of the amplitude of the meander on the windings of the power transformer, the rectified voltage at the input of the transistor 20

becomes below the unlocked threshold and the device automatically turns off. Thus, the protection threshold depends on the voltage transformer ratio on the additional winding and

dividing the resistive divider by resistors 21 and 22. Locking of the transistor 20 and, accordingly, turning off the power source occurs

and in the event of a malfunction (for example, during the breakdown of the power transistors 1 and 2, short circuit of the windings of the power transformer, etc.) due to the termination of the generation of the B converter. In this way, the function of a high-speed electronic fuse is realized, thus providing behind-the-shield and primary power sources.

The magnitude of the voltage amplitude of the additional winding 24 and the base current of the additional transistor 20 are selected to be less than 10%, respectively, of the nominal input supply voltage and current consumption (subject to a transistor gain factor, 20 more than 10} as the power source. Consequently, the power consumption for maintaining the additional transistor 20 in the open state is less than 1% of the power consumed by the device. The auxiliary resistor 23 is designed to limit the current to the control terminal 27, the limitation of the resistor 22 is not enough, since the magnitude of its resistance is determined by the voltage at the output of the direct current. Current through the control terminal 28

limited by base resistors 7 and 8.

Thus, a stabilized power supply at low hardware costs provides enhanced functionality for the electronic switching on and switching off of the source, as well as the ability to memorize the on or off state. source) and increased reliability, (protection against current overload in the load, protection of primary sources in the event of a malfunction in the power source).

Claims (1)

Invention Formula Stabilized power source by author. COV. No. 809116, TLL - TeMj that, in order to increase reliability by ensuring automatic disconnection of the power source during overload and malfunction and functionality, by ensuring electronic switching on and off of the power source, a switching transistor, the type of conductivity opposite to other transistors, is introduced power supply, resistive voltage divider, additional, resistor and winding of the power transformer, expander, switching on and off detecting, with vhod.vypr DC converter connected to the additional winding of the power transformer, and the output through an additional resistor is connected to the inclusive control output and through a resistive voltage divider to the input of the switching transistor, whose collector is connected to the collectors of the power supply transistors, the emitter - to the input power output, switching off the control output is connected to the second terminals Diodes.