SU1644112A1 - Regulated dc voltage converter - Google Patents

Abstract

The invention relates to electrical engineering, in particular to converter equipment, and can be used to supply electronic equipment with stabilized voltage. The aim of the invention is to increase the efficiency and reliability of a stabilized voltage converter. The goal is achieved by the fact that additional windings 9.14 are introduced into output transformer 10, additional winding 5 and a chain of series-connected diode 8 and resistor 9 connecting transformers 4 and 10 are introduced into excitation transformer 4. Thanks to this, a positive feedback circuit is created voltage, allowing to use part of the energy of the output transformer to saturate and force the power switch 1 to shut down. As a result, the conversion efficiency is dramatically reduced. Switching losses of the power switch 1 are sharply reduced and, as a result, the stability of the stabilized converter is increased. 1 il. / WITH

Description

The invention relates to electrical engineering, in particular to converter equipment, and can be used to supply equipment with stabilized voltage.

The aim of the invention is to increase the efficiency and reliability of the stabilized source.

The drawing shows a schematic diagram of the converter.

The converter contains a transistor switch 1, a master oscillator 2, operating on the winding 3 of the excitation transformer 4, the winding 5 of which is connected to the collector of the shunt transistor 6, with a resistor 7

and a diode 8 connected in series with each other and with an additional winding 9 of the output transformer 10. The outputs of the amplifier II voltage error and the generator 12 of the sawtooth voltage are connected to the input of a pulse-width modulator 13, the output of which is connected to the control input of the shunt transistor 6 The second additional winding 14 of the output transformer 10 is connected to a sawtooth generator 12. The winding 15 of the output transformer j j is connected to the collector of transistor switch 1. The windings of the 16 output transformer

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The rectifier's cutout is connected to the output terminals; the winding 17 of the field transformer is connected between the base and the emitter of the power switch 1.

Stabilized Converter works as follows.

When the input voltage is applied, the master oscillator 2 is turned on, producing short pulses and running on the winding 3 'of the excitation transformer 4. The transistor switch 1, connected by the base to the winding 17 of the exciter transformer 4, is opened and connects the winding 15 of the transformer 10 to the source. A voltage is applied to the winding 9 of the transformer 10, which is applied through the open diode 8 and the resistor 7 to the winding 5 of the excitation transformer 4. The polarity of the voltage on the winding 17 of the specified transformer is such that the transistor 1 will remain in the open state despite the fact that the short pulse from the master oscillator 2 has already been removed. Transistor switch 1 will be in the saturated state and transformer 10 begins to accumulate energy. When the base current of the transistor switch 5 drops to the value at which it enters the linear mode, it begins to close. An emf of self-induction appears, the polarity of which is opposite to the former one. Diode 8 closes. The voltage of the winding 17 of the excitation transformer 4 closes the transistor switch 1. Energy from the winding 1 6 of the output transformer I 0 is transferred to the load. The output voltage is stabilized as follows. The next short pulse from master oscillator 2 opens the key 1, which connects the winding 15 of the output transformer 10 to the source. The voltage developed at the output of the converter in the previous cycle is fed to the pulse-width modulator 13 and the error voltage amplifier 11. At the input of the pulse-width modulator 13, the voltage of the amplifier 11 and the generator 12 of the saw-tooth voltage is compared, and at the output - rectangular pulses with varying duty cycle. These pulses open the transistor 6, which shunt the winding 5 of the excitation transformer 4. Positive feedback voltage from the winding

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The output transformer 10 through the diode 8 and the resistor 7 becomes close to zero and the transistor switch 1 closes, since the voltage on the winding 17 of the transformer 4 is also close to zero. The polarity of the voltage on the windings of the specified transformer is reversed, the diode 8 is closed, and the feedback circuit is interrupted for a period of energy transfer to the load.

The use of positive feedback in the circuit of the transistor switch 1 by the appropriate connection of the windings of the output transformer

10 and excitation transformer 4 ensures synchronization of the processes at the input of the switch 1 and at the output transformer 10, and ensures the forced switching of the transistor switch 1, which leads to a decrease in losses on the switch, increasing

Efficiency and increased reliability of the stabilized voltage converter.

Claims (1)

Invention Formula A stabilized DC converter containing a transistor switch, the emitter of which is connected to the first input terminal, and the collector is connected to the first output of the primary winding of the output transformer, the second terminal of which is connected to the second input terminal, the secondary winding of the output transformer is connected to the output side pins that are also connected to the input of the error amplifier voltage, and the outputs of the error amplifier voltage and the sawtooth generator connection The inputs have a wide pulse modulator, the output of which is connected to the control input of the shunt transistor, a master oscillator, the output of which is connected to the first winding of the excitation transformer, the second winding of which is connected between the base and the emitter of the transistor switch, characterized in In order to increase efficiency and reliability by reducing the switching losses of the transistor switch, two additional windings are introduced into the output transformer, and one additional winding is introduced into the output transformer, th 516441 the output of which is connected to the collector of the shunt transistor, and the second output is connected to the first output of the first additional winding of the output transformer, to the emitter of the shunt transistor and to one of the output terminals, while the second output of the first additional winding 12 the output transformer is connected via a series-connected diode and a resistor to the collector of the shunt transistor, and the second additional winding of the output transformer is connected to the control of the input voltage of the sawtooth generator.