SU1241209A1 - Secondary electric power source - Google Patents

Abstract

The invention relates to the field of electrical engineering and can be used in secondary power sources. The purpose of the invention is to increase reliability by protecting the switching transistors from overloads of current and voltage. When an overcurrent occurs, the voltage applied to the transformer 2 increases, when the threshold value is reached, the comparison circuit is activated and the protection transistor 6 is detected. This leads to the locking of the transistors 1, - The introduction of the voltage regulator 9 with the negative feedback circuit ensures the protection of the device against overloads, 1 3, w o f-ly, 2 silt, s e (L Y 4 S O: o fig, ;

Description

one

The invention relates to electrical engineering and can be used in secondary power supply systems for devices in radio engineering, automation, and computer science.

The purpose of the invention is to improve the reliability of the secondary power supply source by protecting the switching transistors against overcurrent and voltage.

FIG. 1 is a schematic diagram of the proposed device; FIG. 2 is a diagram of a constant voltage control unit.

The device contains overlapping transistors 1, an output transformer 2 with primary 3, secondary A and additional 5 windings, a protection transistor 6, interrupting diodes 7 and 8 and a constant voltage control unit 9 including a threshold element 10, constant voltage regulator 1 and feedback circuit 12. The threshold element consists of a comparison circuit 13, the inputs of which are connected to the voltage sensor 14 and: to the supporting element 15. The connection of the voltage converter and the control node is carried out along chains 16-19,

The device works as follows.

In the absence of current overloads, the voltage converter converts a constant voltage,. .induced to the middle terminal of the transformer 2, in the variable, which with the help of the circuit 12 feedback. and the controller 11 is maintained at a constant level. In this case, the protection circuit does not affect n, but the operation of the converter and the power source as a whole. When an overcurrent occurs at the output of the power source, the voltage applied to the middle terminal of the output transformer 2 begins to turn off due to the final value of the internal resistance of the output transformer 2. When the specified voltage increases above a certain given value, the comparison circuit 13 unlocks transistor, 6 protection and through the additional winding 5 and cut-off diodes 7 and 8 for 12412092 guards the switching transistors 1 and thereby protects them from overloads. Similar processes occur with an increase in the voltage supplied to the middle terminal of transformer 2 (for example, with an increase in the specified voltage due to the failure of the constant voltage regulator 11).

10 Thus, the introduction of a constant voltage control unit with a negative feedback circuit improves the reliability of the secondary power supply source by eliminating the overloads of the switching transistors 1 in current and voltage.

20

25

thirty

Claims (2)

Invention Formula - 1. A secondary power supply source containing switching transistors and an output transformer with a medium, primary output terminal, the secondary winding of which is connected to the output terminals, a protection transistor ,; the collector of which is connected through additional windings of the output transformer and cut-off diodes to the bases of the switching transistors, the emitter - to the point of switching over to the output 35 40 50 55 connecting the emitters of transistors, and the base of the threshold element, the input of which is connected to the middle terminal of the output transformer, characterized in that, in order to increase the reliability by protecting the switching transistors against overloads nq current and voltage, a node of a controlled voltage is introduced into it with a negative feedback circuit, the input of which is connected to the output, you - and the output - to the middle terminal of the output winding of the output transformer. 2. Source according to claim 1, in which the threshold element is designed as a comparison circuit, the first input of which is connected to the voltage sensor, the second input to the supporting element, and the output to the base of the protection transistor. Invention Formula - 1. A secondary power supply source containing switching transistors and an output transformer with a medium, primary output terminal, the secondary winding of which is connected to the output terminals, a protection transistor ,; the collector of which is connected through additional windings of the output transformer and cut-off diodes to the bases of the switching transistors, the emitter - to the point of switching over to the output five 0 0 five connecting the emitters of transistors, and the base of the threshold element, the input of which is connected to the middle terminal of the output transformer, characterized in that, in order to increase the reliability by protecting the switching transistors against overloads nq current and voltage, a node of a controlled voltage is introduced into it with a negative feedback circuit, the input of which is connected to the output, you - and the output - to the middle terminal of the output winding of the output transformer. 2. Source according to claim 1, in which the threshold element is designed as a comparison circuit, the first input of which is connected to the voltage sensor, the second input to the supporting element, and the output to the base of the protection transistor. i tt. h .J I Editor A. Orap Compiled by V. Ezhov Tehred L. Oleinik Proofreader M. Sharoshi Order 3487/42 Circulation 836 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 FIG. 2