SU1749996A1 - Device for controlling dc/dc converter - Google Patents

Abstract

The essence of the invention: the device contains an inverter (1), 2 transformers (2, 3), an output transformer (4), 2 capacitors (5, 6), a rectifier (7). filter (8), feedback amplifier (9), comparator (10), sawtooth generator (11), modulation unit (12), output transformer (13), driving oscillator (14). 2 Il.

Description

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

The purpose of the invention is to increase noise immunity.

FIG. 1 is a diagram of a device for controlling a DC / DC converter in FIG. 2, the diagrams of control voltages in a circuit.

A device for controlling a DC / DC converter is performed on a push-pull transistor inverter 1, the output of which is formed by the common emitter point of the first transistor 2 and the collector of the second transistor 3 is connected to the output side of the output transformer 4 of the inverter, the second end of which is connected to the first plates of the first 5 and second 6 capacitors, the second plate of the first 5 capacitors is connected to the collector of the first 2 transistor and is intended to be connected to ozhitelnomu pole of the power source, said second electrode of the second capacitor 6 is connected to the emitter of the second transistor 3 and

The secondary winding of the output transformer 4 is connected via a rectifier 7 to an LC filter 8 containing a feedback amplifier 9, the input of which is connected to the output of an LC filter 8, the output to the first input of the comparator 10, the second input of which is connected to the output of the sawtooth voltage generator 11, the master oscillator 14, the first output of which is connected to the input of the sawtooth voltage generator 11, the transformer output to the input of the modulation unit 12, and the beginning and The secondary secondary winding of the output transformer 13 is connected respectively to the anodes of the first 15 and second 16 diodes, and the middle point to the first output of the comparator 10 and the emitter of the first transistor 17, the base of which is connected to the second output of the comparator 10. The cathode of the first diode 15 is connected to the beginning of the primary winding you turn on the transformer 18 of the modulation unit 12 and with the anode of the third diode 19, the cathode of the second diode 16 is connected to the end of the primary winding of the output transformer

WITH

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yu yu

ABOUT

ora 13 and with the anode of the fourth diodes 20. The collector of the first transistor 17 is connected to the base of the second transistor 22, the cathode of the fifth diode 24 and the first output of the resistor 26, the second output of which is connected to 5 of the first capacitor plate 25, the second facing of which is connected to the anode p the diode 24, the emitter of the second transistor 22 and the midpoint of the primary winding of the output transformer 18. The cathodes 10 of the third 19 and fourth 20 diodes are interconnected and connected to the collector of the second transistor 22.

The first and second secondary windings of the output transformer 18 are connected to 15 driver control pulsers 21, the outputs of which are intended to be connected to the base 2 and second 3 transistors of the inverter respectively, and clock input 20 is connected to the second output of the master oscillator 14 .

On the core of the output transformer 13 there is an additional winding 27 connected to the input of the rectifier 23, 25 whose output is connected to the corresponding first and second plates of the capacitor 25 of the modulation side 12.

The device works as follows .30

The voltage from the output of the LC filter 8 is fed to the input of the feedback amplifier 9, from the output of which the control voltage is fed to the input of the comparator 10. The master oscillator 14 generates 35 rectangular pulses of alternating high-frequency voltage (see Fig. 2a) with a duty cycle of 2, which are fed to the primary winding of the transformer 13, from the first output to the input of the sawtooth voltage generator 1140 and from the second output to the clock input of the control pulse generator 21. From the output of the generator 11, sawtooth pulses go the second input of the comparator 10, 45 as a result of comparing two voltages at the inputs of the comparator 10 at its outputs, a rectangular-shaped pulse voltage (see Fig. 26) is formed with a varying duty ratio depending on the value of the feedback voltage 50 within the half-period of the oscillator generation frequency 14. At the same time, in the time interval ti-ta, the transistor 17 is open (see Fig. 2c) and the half-winding voltage of the transformer is 3 to 55 cut diodes 15 and 24 is applied to the half winding of the transformer 18. Pr Momentum impulse voltage ansformiruets secondary winding of the transformer 18 and, together with the voltage from the second output

the master oscillator 14 through the control pulse driver 21 is supplied to the base-emitter transitions of the power transistors 2 and 3.

The current flowing from the semi-winding of the transformer 13 through the diode 15, the semi-winding of the transformer 18, the diode 24, the open transistor 17, creates a blocking voltage for the transistor 22 on the diode 24. During the operation of the master oscillator 14, the coil 27 is acted on the input of the rectifier 23, and from its output a constant voltage enters the capacitor 25, and during operation of the control device the value of this voltage is always the same and does not depend on the variation of the voltage ratio on the transformer windings and 18.

In the time intervals ta-ts,, te-ty, the transistor 17 is closed by the voltage of the comparator 10, and the transistor 22 is open, as the discharge-current of the capacitor 25, limited by the resistor 26, passes through the base-emitter junction.

Thus, both the half-windings of the transformer 18 are shorted in the pauses between the impedance of the voltage through the open transistor 22 and the diodes 19 and 20. The control voltage on the output windings of the transformer 13 has the shape shown in FIG. 2g.

When the polarity of the alternating voltage on the secondary winding of the transformer 13 at the time interval ta-ts changes, the diode 15 is closed, and the diode 16 opens (see FIG. 2a). In the time interval, the transistor 17 opens and the current from the transformer winding 13 through the diode 16, the half-winding of the transformer 18, the diode 24 and the open transistor 17 is supplied to the middle terminal of the transformer 13.

A rectangular voltage pulse in the gap tz-t / i at the half-windings of transformer 18 is transformed into output windings, and the process of generating control pulses repeats as described in the time interval ti-ta. Noise immunity increases.

Claims (1)

Invention Formula A device for controlling a dc-to-dc converter made on a push-pull transistor inverter, the output of which is formed by the common junction point of the first transistor of the first transistor and the collector of the second transistor, is connected to the primary side of the output transformer of the inverter, the second output of which is connected to the first plates of the first and the second capacitor, the second plate of the first capacitor is connected to the collector of the first transistor and is intended to be connected to the positive power supply polkesu, the second plate The second capacitor is connected to an additional winding connected to the rectifier input, the output of which is connected to the corresponding first and second capacitor plates of the modulation unit. FIG. Phage 2