SU1160516A2 - Bridge transistor inverter - Google Patents

Abstract

1. BRIDGE TRANSISTOR SCHOOL by autor. St. No. 1064404, characterized in that, in order to increase the reliability of the inverter, by synchronizing the switching time of a key with two-sided conductivity with the switching moment of the power keys, a frequency divider is inserted, the output of which is connected: to the control input of a key with two-sided conductivity, and the input connected to the inverter control unit.

Description

L

and

70

9j -

G4

2. The inverter according to claim 1, of which is a proper generator and pulse-width modulator; this is also due to the fact that the control unit, a torus, and the output of the master oscillator contains at least one oscillator connected to the input frequency divider.

The invention relates to electrical engineering and can be used in the sources of secondary power supply systems of radio engineering, automation and computing;

According to the main author. St. No. 1064404 of a non-parable bridge transistor inverter, whose DC diagonal is connected to the input terminals and ends of a capacitor voltage divider, the midpoint of which is connected to the average output terminal of the output transformer connected to the diagonal of the inverter AC, and the average output voltage of the primary output winding the transformer and the midpoint of the capacitor voltage divider are connected via a switch with two-way conductance 03

A disadvantage of the known device lies in its low reliability due to the fact that in a short-term operation mode, which may be accompanied by increased electromagnetic loads, it is necessary that the switching frequency of a switch having two-way conductivity is as close as possible to the switching frequency of the inverter power switches. as the release of significant dynamic losses on the same key during 5-tО and more periods of the output voltage of the order dramatically increases the likelihood of secondary wow breakdown of transistor structures. If, however, the switching frequencies of the mentioned switches are close, the time of dissolving local overheating in the structures will be at least twice as high, and this reduces the likelihood of secondary irobo. However, the reliability of the circuit as a whole can be reduced if, at close frequencies, the switching moments of a key with two-way conductivity are not synchronized with the switching of the power switches, especially when the time is closed.

11605.16

The state of the specified key is not equal to the open time. The consequence of this may be the magnetization of the transformer, which causes in some cases an increase in magnetizing current. Increased static loss in individual keys is also possible. It also reduces the reliability of the inverter.

The aim of the invention is to increase the reliability of the inverter by synchronizing the moment of switching the key, which has two-way conductivity, with the moment of switching the power keys.

The goal is achieved by those. that a frequency divider is inserted in the bridge transistor inverter, the output of which is connected to the control input of a switch with two-way conductivity, and the input is connected to the inverter control unit.

In this case, the control unit contains at least one reference oscillator and a pulse-width modulator, the output of the reference oscillator is connected to the input of the frequency divider.

FIG. 1 shows a diagram of the proposed device; in fig. 2 - temporary diagrams in I.

The inverter contains transistor switches t-4j forming a bridge circuit, to the diagonal 5-6 of the direct current of which the capacitor voltage divider 7-8 is connected. The primary half winding 9 of the transformer 10 is connected to the diagonal of the AC inverter. The middle terminal 11 of the primary winding of the transformer 10 is connected to the middle point 12 of the capacitive divider 7-8 through a switch 13, which has two-sided conductivity. A master oscillator 14, a pulse width modulator 15 and a frequency divider 1-6 are introduced into the circuit. The outputs of the pulse-width modulator 15 are connected to the corresponding control terminals of the transistor switches 1-4. The inputs of the module 3 1 of the torus and the frequency divider are connected to the output of the master oscillator 14. The output of the frequency divider is connected to the control terminals of the key 13. The inverter works as follows. The voltage from the back of the generator (Fig. 2,) is fed to the input of the pulse-width modulator 15, where Control signals dp of keys 1-4 are formed (Fig. 2, rf, b). The voltage from the output 16 of the frequency divider (Fig. 2, z) controls the switching key 13 (a positive signal at the output of the frequency divider corresponds to the open state of the key 13). The agrdmne (Fig. 2a) shows the shape of the output voltage of the inverter. Obviously, the switch key 13 in the proposed inverter is carried out on

f /

UfA

and,

P

y /, /

P

P 164 the interval of the pause of the output voltage. In this case, for each interval of the closed, as well as the open, state of the key 13, there is an integer number of half-voltages of voltage of close duration. Despite the fact that the half-wave duration in the closed state of the key is longer than in the open state, the constant component in the output voltage is practically absent. Preferably, the inverter is distinguished by increased reliability due to minimization of the constant component of the output voltage, namely, due to synchronization of the switching time of the key with two-sided conductivity with the switching time of the blue keys of the inverter.

Claims (2)

1. BRIDGE TRANSISTOR INVERTER by ed. St. No. 1064404, characterized in that, in order to increase the reliability of the inverter by synchronizing the moment of switching the key having two-sided conductivity with the moment of switching the power keys, a frequency divider is introduced, the output of which is connected to the control input of the key having two-sided conductivity, and the input connected to the inverter control unit. 11605.16 2. Inverter by π. 1, the result is that the generator is pulse-width pulsed by the fact that the control unit is an oscillator, and the output of the master oscillator contains at least one master connected to the input of the frequency divider.