SU1705985A1 - Regulated dc voltage converter - Google Patents

Abstract

The invention relates to electrical engineering, in particular to sources of secondary power supply of electronic equipment. The goal is to improve the quality of output voltage stabilization in the case of the implementation of the secondary circuit of a power transformer according to the full-wave voltage rectifying circuit. The device contains a transistor half-bridge, in the output diagonal of which through a transformer and a full-wave rectifier the load is included. In the emitter circuit of one and the collector circuit of another transistor, the working windings of a magnetic amplifier, made on two magnetic cores, are introduced. The control windings of the magnetic amplifier close the source feedback loop of the voltage. A distinctive feature of the device is the presence of two series-connected additional windings of the magnetic amplifier, which are located in the antiphase branches of the secondary circuit of the transformer. This technical solution makes it possible to bring the initial bias current of the magnetic amplifier to zero and equalize the magneto-motive forces due to the load current in the working and control half-periods. 2 Il. WITH S

Description

The invention relates to electrical engineering, namely to power supplies with a transformerless input, and can be used in power supply systems for automation devices, computing equipment and radio equipment.

The purpose of the invention is to increase the stability of the stabilized parameter.

FIG. 1 is an electrical diagram of a stabilized DC converter; figure 2 - diagrams.

The stabilized DC converter contains an input filter on capacitors 1 and 2, the midpoint of which through the primary winding 3 of transformer 4 is connected to the connection point of the working windings 5 and 6 on the cores 7 and 8 of the magnetic amplifier, the other ends of the windings 5 and 6 through transistors 9 and 10 is connected to capacitors 1 and 2, the master oscillator 11 through control transformer 12 and limiting resistors are connected to control electrodes of transistors 9 and 10. windings

Xi

ABOUT

ate about burned

The control units 13 and 14 of the MU are connected via the choke 15 to the measuring amplifier unit 16, the input of which is connected to the load 17 (feedback output) connected via diodes 18-21 and additional windings 22 and 23 to the secondary winding 24 of the transformer 4, recuperative diodes 25, 26 connect the leads of the primary power supply to the power leads of the transistors.

The master oscillator 11 generates control pulses which control the transistors 9 and 10 through the transformer 12. The current limiting resistors are included in the base circuits of the transistors 9 and 10. The switching of transistors 9 and 10 is in antiphase. The choke 15 is connected in series with the windings 13 and 14 of the cores 7 and 8 MU and ensures its operation in the forced magnetizing mode. Working windings 5 and 6 MU are connected in series with transistors 9 and 10 and provide parametric limiting of collector currents. Such an inclusion of MU windings is inherent in magnetic amplifiers with self-saturation, and the operation mode in the device is implemented in the negative feedback region, which is characterized by a significant initial magnetic bias current (with the half-bridge inverter operation mode with MW operating windings connected in series with transistors, see prototype).

The voltage is stabilized by the control current of the magnetic amplifier flowing through the windings 13 and 14. As a regulating element of the magnetic bias current, the measuring and amplifying unit 16 controlled by the load voltage 17 is used. The measuring and amplifier unit 16 is made according to the well-known solution (see prototype). With an increase in the voltage on the load, the bias current decreases, i.e., the resistance to the alternating current MU increases, and consequently, the load current and voltage on the load decrease.

An increase in the voltage stability or load current in the proposed device is achieved by separating additional windings 22 and 23 MW included in the circuits of the diodes 18 and 19.

Let transistor 9 be open and transistor 10 closed. The core 7 MU is in the working, and the core 8 is in the control half period. The current in the primary circuit of the transformer flows from the upper plate of the capacitor 1 through the open transistor 9, the working winding 5, the core 7 MU, the primary winding 3 of the transformer 4 to the bottom plate of the capacitor 1. From the secondary winding of the transformer the load current flows from the right output of the secondary winding 24 of the transformer 4 through the diode 20, the load 17, the diode 19, the additional winding 23 of controlling the magnetic amplifier 8 MU, the left terminal of the secondary winding 24 of the transformer 4. By selecting the number of turns of the additional windings 22 and 23 MU, you provide mc is close to zero the initial control current, i.e. the equality of the magnetomotive forces in the control and working half periods of the MU is achieved.

iws w5 iw23 w23,

OR

Iw6 W6 Iw22 W22,

where ws; we; W22; W23; iw5; iw6; iw22; | w23 is the number of turns of working 5, 6 and additional 22, 23 windings of MU and the corresponding currents.

Thereby, the control range of the gain coefficient MU and the stability of the output current or voltage are increased.

In addition, the introduction of additional windings in the MU allows to extend the positive effect obtained in the prototype for half-bridge interiors on two-stroke and bridge circuits of inverters.

In the bridge inverter circuit, the working windings are split in half and included in the diagonal of the bridge. When you turn on the working windings 5 and 6 MU in the power circuit of transistors 9 and 10, it is necessary to ensure the return of the energy MU stored by the recovery diodes 25 and 26, as shown in FIG.

The current on the winding 23 flows when the core 8 is in the control half-period, and the core 7 is in the working one. MU operation in the parametric current limiting mode.

Claims (1)

Claims of the Invention A direct current voltage regulating converter comprising two capacitors, the first plates of which are connected to the terminals for connecting the primary power source, two transistors, the basic circuits of which are connected to the output of the master oscillator, power transformer, through current limiting resistors and the secondary circuit of which is connected to the terminals for connecting the load, a magnetic amplifier with two magnetic cores and workers and control devices placed on them windings, measuring and amplifying unit, the input of which is connected to the feedback output of the converter, and the output through the choke to the series-connected control windings of the magnetic amplifier, characterized in that, in order to improve the quality of the output voltage stabilization in the case of a circuit secondary winding of a power transformer according to the scheme of full-wave rectifier m0 five neither the voltage, the magnetic cores of the magnetic amplifier are applied in accordance with the workers and control windings of two series-connected additional windings introduced into the antiphase branches of the secondary circuit of the power transformer, the working windings of the magnetic amplifier are connected in series between the emitter of the first and the collector of the second transistor, the other power terminals of which are connected with appropriate leads for connecting the primary power source, and the primary winding of the power transformer is connected between do the common conclusion of the working windings of the magnetic amplifier and the second capacitor plates interconnected. by Jm 4U / FIG. 2