SU1504772A1 - D.c. to sine a.c. voltage converter - Google Patents

Abstract

This invention relates to electrical engineering and can be used in secondary power supply sources. The purpose of the invention is to increase reliability by improving startup conditions. Constant voltage to AC sinusoidal converter contains an inverter with a transformer 1, the primary winding 2 of which is bridged by a capacitor 16, a two-winding filter choke 4, power transistors 5, 6, control transistors 7, 8 with a winding 11 of the transformer 1. Second winding 15 droselle connected to the control key 14, the control input of which is connected to the output of the delay unit 13. When the converter is turned on, the delay unit 13 unlocks the controlled key 14, which shunts the second winding 15 droplets of the filter 4, which reduces the inductive resistance of the drosel of the filter 4. A more sharp increase in the current in the windings of the droplets of the filter 4, transformer 1 and in the condenser 16 resonant circuit formed by the transformer 1 and the capacitor 16. 2 Cp f-ly, 2 ill.

Description

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.31504772

: The invention relates to electrical engineering and can be used in

Sources of secondary power supply

Systems radio engineering, automation and computing.

The aim of the invention is to increase the reliability of the converter by

Improve launch conditions.

 FIG. 1 shows the electric

| constant converter circuit

Strain into sinus-adapted; Fig. 2 are belt diagrams of currents and voltages.

j Constant voltage converter - 15, which accordingly removes additions into an alternating sinusoidal substantial (initial) current (26, fig, 2)

Holds inverter, secondary winding

transformer 1 is connected to the output terminals, and the primary (2) is connected through the first winding 3 droplets 20 of the resistance value of the resistor 25

filter 4 with the first input pin and is able to ensure stable start

| through power transistors 5, 6 - with

| second input pin J control

Transistors 7, 8, connected to the base of the power transistors 5, 6 through 25

the first 9 and second 10 resistors and under: the connected bases to the extreme conclusions

control windings 11, average output

: which is connected via a third resis; torus 12 with a second input terminal; 30 transformer 11 (28, in Fig. 2)

| block 13 delay, the output of which falls to a steady-state value.

Close to the input of the control key 14; Thus, in the proposed scheme, the second winding of the 15 throttle filter is connected in parallel, as well as the capacitor 16 connected in parallel

The primary winding of the transformer.

| BLOCK 13 delay can be performed

IB as a resistive divider on the resistors 17, 18, one of which is shunted by a capacitor 19 and connected 40

 the average output 20 through the Zener diode 21 and the resistor 22 with the output output of the delay unit. The control key 14 can be performed on a transistor 23, which is connected to the second winding 15 45 containing a push-pull inverter, a drosel filter. 4 through the diode 24 and the secondary winding of the transformer, the resistor co-resistor 25. is connected to the output; the converter works as follows, middle output of the primary winding, capacitor-controlled way, connecting the power supply through the first winding of the throttles to the input pins of the control key 14 is opened by the charge current of the capacitor 19 of the delay unit 13. Closing, key 14 forms a circuit for current flow through the second winding 15 of the throttle to the second input terminal, and filter 4. Resistor 25 limits the bases connected through the first and second current through the second 15 and corresponding resistors to the output of the control unit, but the first 3 windings of the throttle filter whose input is connected to the winding of the R4. By choosing the magnitude of the J control of the transformer, average

Resistor 25 can set the initial current (26, Fig. 2) through the power transistors 5 and 6 and the oscillating circuit (winding 2 of the transformer - capacitor 16).

As the capacitor 19 is charged, the voltage at the output of the delay unit 13 decreases and when it reaches a predetermined value, the key 14 closes as the current in its base breaks (via resistor 22 and zener diode 21). With the opening of the key 14 opens the circuit of the second winding

in the first winding of 3 droplets of the filter 4. By choosing the constant charging time of the capacitor 19 of the block 13 of the delay and

the converter and its output to the nominal mode for a specified number of oscillation periods.

At the moment of starting the converter, the current consumption in the first period of time increases (26, fig. 2), and after the development of stable oscillations in the filter choke (27, fig. 2) and at the output

I ensure steady starting of the converter in self-oscillatory mode, while limiting the value of the initial (starting) current (26, Fig.2) through transistor switches, which increases the reliability and facilitates the starting of the converter.

Claims (1)

1. Converter DC voltage to AC sinusoidal filter with the first input output, and the extreme conclusions of the primary winding are connected to the collectors of power transistors, the emitters of which Resistor 25 can set the initial current (26, Fig. 2) through the power transistors 5 and 6 and the oscillating circuit (winding 2 of the transformer - capacitor 16). As the capacitor 19 is charged, the voltage at the output of the delay unit 13 decreases and when it reaches a predetermined value, the key 14 closes as the current in its base breaks (via resistor 22 and zener diode 21). With the opening of the key 14 opens the circuit of the second winding in the first winding of 3 droplets of the filter 4. By choosing the constant charging time of the capacitor 19 of the block 13 of the delay and the converter and its output to the nominal mode for a specified number of oscillation periods. At the moment of starting the converter, the current consumption in the first period of time increases (26, fig. 2), and after the development of stable oscillations in the filter choke (27, fig. 2) and at the output Thus, in the proposed scheme, a stable starting of the converter in a self-oscillating mode is provided while limiting the value of the initial (starting) current (26, FIG. 2) through transistor switches, which increases the reliability and facilitates the starting of the converter.  containing a two-stroke inverter, the secondary winding of the transformer of which is connected to the output formulas of the invention 1. A DC to AC converter through the first winding of the throttle is connected to the second input terminal, and the bases are connected through the first and second resistors to the output of the control unit, the input of which is connected to the control winding of the transformer, medium the filter with the first input terminal, and the extreme terminals of the primary winding are connected to the collectors of power transistors, the emitters of which are connected via a third resistor to the second input terminal, characterized in that, in order to increase the reliability by improving the starting conditions, a controllable key is entered, second the filter throttle winding and a delay unit connected by the input to the input terminals, and the output to the control input of a controllable switch connected in parallel to the second winding of the filter throttles. 2, the Converter according to claim. I, t that the delay unit is made in the form of a resistive voltage divider, the extreme conclusions which is connected to the input pins, one of the resistors is bridged by a capacitor, and the middle output is connected via a zener diode and a resistor to the output terminal of the delay unit, 3, the converter according to claim 1, about t is that the controlled key is made on a transistor, the emitter of which is connected to the second input terminal, the base is connected to the output of the delay unit, and the collector is connected via a diode to the first output of the second winding of the drossel Ultra, the second terminal of which is connected via a resistor to the emitter of the transistor. Fi & 2