SU1615850A1 - Stabilized d.c. to d.c. voltage converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in secondary power sources. The purpose of the invention is to increase efficiency and improve electromagnetic compatibility with electronic equipment. The invention consists of transistors 3,4, input capacitors 5, 6 and transformer 7. The choke 8 is connected to the inverter’s alternating current target, forming an LC circuit with a transformer, pulse drivers 21, 22 and a current transformer 23 are introduced. current-free switching of the inverter transistors and by reducing the reverse voltage of the rectifier diodes. 2 Il.

Description

FIG. one

The invention relates to electrical engineering and can be used to power electronic equipment.

The purpose of the invention is to increase the efficiency and improve electromagnetic compatibility with electronic equipment,.

FIG. 1 shows the scheme of the proposed converter; 2, time diagrams of the converter operation.

The stabilized DC / DC converter contains a transistor-transformer inverter connected to input pins 1 and 2 and consisting of transistors 3 and 4, input capacitors 5 and 6 and a transformer 7, the choke 8 connected to the inverter’s AC circuit LC circuit. In addition, the converter contains a capacitor 9 connected in parallel to the secondary winding of the transformer 7, to the terminals of which diodes 10 and 11 of the same name are connected, the other terminals of which are connected to the first output terminal 12 connected to the second output terminal 13 through a filter capacitor 14, inductors 15 and 16 filters, a voltage divider 17, an amplifier 18, a voltage source 19, a two-stroke pulse frequency modulator 20, pulse drivers 21 and 22, a current transformer 23, additional diodes 24 and 25, and resistors 26 and 27.

In the diagrams (FIG. 2) indicated; 1k (1) -current in the circuit of drossel 8, UK (t) - the voltage on the capacitor 9, UTi (t) - the voltage on the transistor 3, UT2 (t) - the voltage on the transistor 4.

The Converter operates as follows.

In the steady state, the starting inputs from the outputs of the drivers 21 and 22 to the control inputs of the transistors 3 and 4 are alternately received. The instant of time with the arrival of the next pulse, for example, is opened at the input of transistor 3, and the supply voltage is applied to transistor 4. The current through the transistor 3 begins to increase in a sinusoidal law defined by the choke 8 and the capacitor 9, forming a resonant circuit. The diode 11 is open under the action of the current drossel 16 filter flowing through the circuit of the choke 16 filter-. ra, filter capacitor 14, diode 11, the voltage on the capacitor 9 increases as the current through the inductor 8 increases, the filter chokes 15 current flowing through the circuit, the filter choke 15, the filter capacitor 14, the diode 11, the capacitor 9, a partial discharge of the capacitor 9.

As a result, the maximum voltage on the capacitor 9 does not correspond to the zero current in the inductor 8.

At time ti current in the resonant

the circuit is reduced to zero, then increases in the opposite direction and closes along the circuit the primary winding of the transformer 7, the choke 8, the additional diode 24, the input capacitor 5, the transformer 23

0 current. At time t2, the voltage on the capacitor 9 decreases to a value which, when converted to the primary winding of the transformer 7, is equal to the voltage of the power source. At the same time reverse current

6, the resonant circuit is reduced to zero, the additional diode 24 is closed. At the instant of time ts, the capacitor 9 is completely discharged, the current of the filter’s throttles 15 is closed through the unlocking diode 10 and

0 filter capacitor 14. Further, with the arrival of a start-up pulse to the input of transistor 4, processes similar to those described, characterized by a change in the polarity of the voltage across the capacitor 9, occur,

5 of the direction of current flow in choke 8, and the operation of all symmetrical elements in the circuit is reversed. The duration of the pulses from the outputs of the formers 21 and 22 should be longer than the half-cycle of current oscillations in the resonant circuit, but shorter than the minimum pulse period at the output of the frequency-pulse modulator 20.

Feedback system stabilizes

5 output voltage by varying the frequency of the starting pulse from the outputs of the formers 21 and 22 with changes in the load or the input voltage. Application of the proposed

0 converter increases efficiency and improves. em electromagnetic compatibility with electronic equipment. The efficiency increase is achieved by performing a current-free switching of the inverter transistors, as well as by halving the reverse voltage; I have a rectifier diode. When used in a Schottky diode rectifier, a decrease in the reverse voltage on them gives a significant gain in efficiency due to a decrease in the leakage current through them. The improvement in electromagnetic compatibility is achieved by eliminating the sudden changes in the current in the inverter transistors and the rectifier diodes.

five

Formula of the Invention Stabilized DC / DC converter containing a push-pull transistor-transformer inverter connected to the input terminals with a choke in the AC circuit forming a resonant circuit with a capacitor connected in parallel to the secondary winding of the transformer whose terminals have the same outlets diodes, the other outputs of which are combined and connected to the first output terminal connected to the second output terminal through a filter capacitor, two filter droplets, a voltage divider whose input is connected to output pins, and an output is connected to the first input of an amplifier, the second input of which is connected to a reference voltage source, and the output is connected to an input of a push-pull frequency-pulse modulator, which differs from the fact that, in order to increase efficiency and improve electromagnetic compatibility with electronic equipment, two pulse shapers were introduced, a current transformer, the primary winding of which is connected to an alternating circuit

current of the inverter, and the secondary windings of the current transformer and the outputs of the pulse formers are connected to the control inputs of the inverter transistors, the inputs of the pulse formers are connected to the output of a two-stroke frequency-pulse modulator resonant circuit, with some of the terminals of the filter chokes are connected to the plates of the condenser, and the others are combined and connected to the second output water

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ABOUT.

Claims (1)

Claim A stabilized DC-DC converter containing a push-pull transistor-trans5 format inverter connected to the input terminals with an inductor in the alternating current circuit forming a resonant circuit with a capacitor connected in parallel with the secondary winding of the transformer, to the terminals of which are connected the same outputs of the diodes, other outputs which are combined and connected to the first output terminal connected to the second output terminal through the filter capacitor, two filter chokes, div a voltage amplifier, the input of which is connected to the output terminals, and the output is connected to the first input of the amplifier, the second input of which is connected to a reference voltage source, and the output 15 is connected to the input of a push-pull frequency-pulse modulator, characterized in that, in order to increase the efficiency and improve electromagnetic compatibility with electronic equipment, two pulse shapers were introduced, a current transformer, the primary winding of which is included in the inverter's alternating current circuit, and the secondary windings of the current transformer and the outputs of the pulsers are connected to the control inputs of the inverter transistors, the inputs of the pulse shapers are connected to the output of a push-pull frequency-pulse modulator, the pulse repetition period of which is longer than the duration of the pulse shaper period, which is also longer than the half-period of the resonant circuit oscillations, and some outputs of the filter chokes are connected to the capacitor plates, and others are connected and connected to the second output pin.