SU1697222A1 - Single-cycle dc/dc converter - Google Patents

Abstract

The invention relates to converter equipment and can be used in secondary power sources. The purpose of the invention is to expand the functionality by expanding the range of output voltage control. In the converter containing transistor 2, diode 6, chokes 7 and 8, transformer 9 with two primary windings 9.1 and 9.2 and secondary winding 9.3, rectifier 10 and filter 11, transistors 3 and 4 and diode 5 are inserted and the functional connections are changed. At any moment of the switching interval, the energy is fed to the output of the converter, which allows varying the transmission coefficient over very wide limits. Transformer 9 operates on a full magnetic cycle, and its winding is continuously flowing around it. 2 Il.

Description

(L

WITH

The invention relates to converter equipment and can be used in secondary power sources.

The aim of the invention is to enhance the functionality by expanding the range of output voltage control.

FIG. 1 shows a flowchart of a converter; in fig. 2 - time diagrams of his work, where i and U are the currents and voltages of the corresponding elements.

The converter contains the first 1.1 and second 1.2 input terminals, transistor 2, first 3 and second 4 additional transistors, additional diode 5, diode 6, first 7 and second 8 chokes, transformer 9 with primary windings 9.1 and 9.2 and secondary winding 9.3, rectifier 10, filter 11 and output pins 12.1 and 12.2.

The proposed Converter works as follows.

At time ti, transistors 2 and 3 are simultaneously turned on, and the input voltage present on input pins 1.1 and 1.2 is applied with the polarity indicated in FIG. 1 without brackets, to the throttles and to the primary windings of the transformer, through which the current closing through transistors 2, 3 and two parallel circuits choke 7 begins to penetrate - winding 9.2; winding 9.1 is choke 8. Under the action of an applied voltage, the current of these circuits increases and energy accumulates in the throttle. At time tz, the transistor 3 turns off, the voltage across the droplets x 7 and 8 changes sign and acquires the polarity indicated in FIG. 1 in brackets. On the winding

th VI th go

The transformer voltage polarity remains the same. The chokes begin to transfer the energy stored in them, the current of each of them is closed through the same primary winding of the transformer, diode 5 and transistor 2. At time t3, transistor 2 turns off and transistor 4 turns on. In this case, the voltage on the transformer windings also changes sign ( the polarity is shown in Fig. 1 in brackets), the current of the 7 drossel flows through the circuit: (+) 7 - diode 6 - the transistor 4 - the winding 9.1 - (-) 7, and the current of the drossel 8 - along the circuit: (+) 8 - winding 9.2 - diode 6 - transistor 4 - (-) 8. The energy stored in the throttle continues to be transmitted from the load. At time t4, transistor 4 is turned off and transistors 2 and 3 are turned on again. The described processes are repeated. The open state time of transistors 2 and 4 is chosen equal to half the switching period, i.e. t02 T / 2. Drive Ratio

KN - - 2pooz,

where uz - relative time of the closed state of the transistor 3:

sh „- t03 vaz - -,

DH is the load voltage;

E is the power supply voltage;

p - transformation ratio, p

 W9 3 / W9 1 + W9.2I

w is the number of turns of the corresponding windings.

Obviously, with a decrease in the impedance, the transmission coefficient and, therefore, the output voltage can be reduced to zero. If t03 T / 2, then Kn p.

The proposed Converter has a wide range of adjustment of the transmission coefficient, and in the whole range

-

ten

15

20

25

thirty

35

40

Electromagnetic elements operate in a favorable, energetically favorable mode. In the load circuit energy flows continuously. The voltage on the transformer windings has the form of a meander, therefore its magnetic core operates on a full magnetic cycle, all the windings of the transformer are constantly flowing around the current.

Claims (1)

Invention Single-ended DC / DC converter containing a transformer with two primary windings, the secondary winding of which is connected to the output terminals through a rectifier with a capacitive filter, the first terminal of which is connected to the beginning of the first primary winding of the transformer, the second output is to the beginning of the second primary winding of the transformer, the second choke is connected to the end of the first primary winding of the transformer with its first output, and the second output to the end of the second transformer primary, a diode and a transistor, through a power transition of which the first output of the first throttle is connected to the first input output, characterized in that, in order to extend the functionality by expanding the control range, an additional diode and two additional transistors are introduced, the second the output of the second throttle through the power transition of the first additional transistor is connected to the second input and simultaneously through an additional diode to the first, and the second output of the first d The power supply through the diode and the power transition of the second additional transistor is connected with the first output of the second droplet. 12.2 0g.1 FIG. 2