SU1749890A1 - Low-voltage stabilized power supply - Google Patents

Abstract

Use: in secondary sources of power supply for electronic equipment, which requires increased efficiency and reliability. SUMMARY OF THE INVENTION: The device comprises a power transformer with a primary winding, a main and auxiliary windings with average leads, a main and auxiliary smoothing capacitors, rectifying transistors, power transistors and matching transistors, a measuring amplifier unit. The connection of the extreme leads of the auxiliary secondary winding with the bases of the rectifying transistors, the middle lead with the collector of the matching transistor and the power supply of the measuring and amplifying unit directly, and with the collectors of the rectifying and power transistors through the auxiliary smoothing capacitor, it reduces the power loss and simplifies the device thereby increasing its efficiency and reliability. 1 Il C

Description

The present invention relates to electrical engineering and can be used in the design of secondary power supply sources.

Low voltage power supplies are known that have been made using DC compensatory stabilizers and have a low power dissipation and an increased efficiency.

In one of the known sources, the power dissipation is reduced due to the separation of the power and matching circuits of the regulating transistor, and the matching circuit is fed from a separate input voltage source. The disadvantage of this source is the complexity of the design scheme, so

as a separate additional input voltage source is needed.

In another known source, matching circuits are powered by a voltage of a smoothing DC filter connected at the input of a power smoothing LC filter. The disadvantage of this source is its narrow application capacity due to the need to use a smoothing LC filter.

From the known sources, the closest in technical essence and adopted for the prototype is a low-voltage stabilized power supply containing a power transformer with a primary winding connected to the input terminals for connecting a source of supply voltage, with a primary secondary winding connected to the outermost XI

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water to the collector of the power transistor through the emitter-collector circuit of the rectifying transistors, and the average output

- to the common busbar, and the auxiliary secondary winding, the main smoothing capacitor connected between the collector of the power transistor and the common bus, the auxiliary smoothing capacitor, the matching transistor, the emitter of which is connected to the output terminal through the base-emitter circuit of the power transistor, and the base - to the output measuring - amplifier knot.

In this source, the auxiliary secondary winding of the power transformer is used to power the matching circuits, the rectifying elements are made on transistors.

However, its significant drawbacks are low efficiency and reliability due to the increased power dissipation of the rectifying transistors and the complexity of the circuit.

The aim of the invention is to increase efficiency and reliability by reducing power loss and simplification.

The goal is achieved by the fact that in a low-voltage stabilized power supply containing a power transformer with a primary winding connected to the input terminals for connecting a power supply source to the main secondary winding connected to the collector of the power transistor through emitter-collector rectifying transistors , and the middle output - to the common bus, and auxiliary secondary winding, the main smoothing capacitor connected between the power collector transistor and common bus, auxiliary smoothing capacitor, matching transistor, the emitter of which is connected to the output terminal through the base-emitter circuit of the power transistor, and the base

- To the output of the measuring and amplifying unit, the extreme leads of the auxiliary secondary winding are connected to the bases of the rectifying transistors in the antiphase, the middle lead is connected to the collector of the matching transistor and to the power supply of the measuring and amplifying unit through parallel connected collectors smoothing capacitor and inserted resistor.

Transitions base-collector rectifying transistors provide a voltage relief of the auxiliary

secondary winding, and thus the circuit is simplified, the power loss is reduced. The analysis of the scientific, technical and patent literature did not reveal similar technical solutions.

The drawing shows an electrical circuit of the proposed low-voltage stabilized power supply.

0 The proposed low-voltage stabilized power supply contains a power transformer 1 with primary 2, main 3 and auxiliary 4 secondary windings, rectifying

5 transistors 5, 6, primary 7 and auxiliary 8 smoothing capacitors, power 9 and matching 10 transistors, measuring and amplifying node 11, output terminal 12, common bus 13 and resistor 14.

0 The matching transistor 10 can be performed in a composite circuit.

The primary winding 2 of the power transformer 1 is connected to an input terminal for connecting a variable source

5 voltage, for example, a rectangular form of high frequency, the extreme terminals of the main 3 secondary winding through transitions emitter-collector of rectifying transistors 5, 6 are connected to the collector

0 of the power transistor 9, its middle output is connected to the common bus 13, the main smoothing capacitor 7 is connected between the collectors of the rectifying transistors 5, 6 and the common bus 13 Extreme conclusions

5 of the auxiliary secondary winding 4 in antiphase are connected to the bases of the rectifying transistors 5, 6, the middle terminal is directly connected to the collector of the matching transistor 10 and with the terminal

0 of the power measuring node 11, and through parallel connected auxiliary smoothing capacitor 8 and resistor 14 is connected to the collectors of rectifying transistors 5, 6 The emitter of the coaxial transistor 10 through the base-emitter junction of the power transistor 9 is connected to the output-output 12, and the base connected to the output of the measuring and amplifying node 11.

0The proposed low-voltage stabilized power supply operates as follows

The rectifying transistors 5 6 are switched on alternately, depending on the voltage pitch on the main secondary winding 3. In the unlocked rectifying transistor (for example, 5), the collector-base junction is shifted in forward direction, for example, by the voltage of the auxiliary secondary winding what

provides the mode of its deep saturation, the bias current flowing through the circuit: the middle output of the auxiliary secondary winding 4, resistor 14, the collector-base transition of the rectifying transistor 5, the extreme output of the auxiliary secondary winding 4, on the resistor 14 creates a voltage drop required for power the collector circuit of the matching transistor 10 and the power output of the measuring-amplifier unit 11, providing lower voltage and power dissipation of the power transistor 9, i.e. The proposed technical solution allowed the rectifying transistors 5, 6 to be used to form two DC voltages: the supply voltage of the collector circuit of the power transistor 9 (created using the main secondary winding 3 and the emitter-collector junctions of the rectifying transistors 5, 6) and the collector supply voltage the chain of the matching transistor 10 (created using an auxiliary secondary winding 4 and the collector-base transition rectifying transistors 5, 6).

As a result, one rectifying unit is eliminated, i.e. the circuit is simplified, and at the same time the power dissipated by the rectifying transistors 5, 6 is reduced due to their operation in the deep saturation mode. This increases the efficiency and reliability of the proposed low-voltage stabilized power supply.

Experimental studies have confirmed the performance of the proposed low-voltage stabilized

power source Compared to the prototype, the proposed source contains 3 elements less, the power dissipated by the rectifier transistors 5, b

reduced by 7 times.

Claims (1)

The invention is a low-voltage stabilized power supply containing a power transformer with a primary winding, connected to the input pins to connect the power supply source, with the main secondary winding connected to the extreme leads to the collector of the power transistor through a circuit the emitter-collector of rectifying transistors, and the middle output to the common busbar, and the auxiliary secondary winding, the main smoothing capacitor connected between the power collector transistor and a common bus, an auxiliary smoothing capacitor, a matching transistor, the emitter of which is connected to the output terminal through the base-emitter circuit of the power transistor, and the base - to the output of the measuring and amplifying unit, characterized in that, in order to increase efficiency and reliability by reducing power losses and simplify, the extreme leads of the auxiliary secondary winding are connected to the bases of the rectifying transistors in antiphase, the middle lead is connected to the collector of the matching transistor and the power input measuring - the amplifier node directly, and rectifier collectors transistors through a parallel-connected auxiliary smoothing capacitor and a resistor introduced. Mr