SU1527696A1 - Adjustable semibridge inverter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in secondary power supply and automation systems. The purpose of the invention is to increase reliability by providing pulse width modulator operation that is symmetric over half periods. In a half-bridge inverter, the power transistors 1 and 2, alternately operating in half-periods, are controlled by rectangular pulses of the output transformer 25 of the master oscillator 13 and by width-modulated pulses of the output transformer 16 of the pulse width modulator 12. Full-wave rectifiers on diodes 30 - 33 provide for locking the power transistors 1 and 2 in the interval of the pause of the width-modulated pulses. 3 il.

Description

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This invention relates to electrical engineering and asks for use in secondary power supply and automation systems.

The purpose of the invention is to increase reliability by ensuring that the pulse pyrin modulator operates symmetrically over half-periods of operation.

Figure 1 is a diagram of a regulated inverter; Fig. 2 shows diagrams of stresses on the circuit elements; FIG. 3 shows the connection circuit of push-pull rectifiers,

Adjustable inverter (fig, 1) provides a series circuit of power transistors 1 and 2, vkpüms; g,;, HI 1PC1,, ami source 3 p1 ta1P1, Jer png chap A of power p1) anusormator 5 is connected to the connection points transistors 1

112 and capacitors 6 and 7 half bridge. The output winding 8 is via an external device; a second device 9, for example, a rectifier, is connected to the load 10 Enhance: feedback ip11 is connected between} L11p m1; lem 9 and the modulator

12 pulse widths. The master oscillator 13 nmlod is connected to the controlleen circuit of the modulator 12. The secondary windings 1A and 15 of the output transformer of the mother 16 g - the tuner 12 are connected to opposite terminals 17-20 through the common PCs. Ave 21 and 22 to the terminals of the base and emitter .. in the respective inputs yiii. 1 p. Penny tranpistors and Secondary .1 windings 23 and 24 of the output frequency of the photon generator maorp 25 of the master oscillator pa pa i i n i n y o p i p y 26-2 bp; shulyuchen to od om o (ny conclusions, tribute: Sor Tea - to the cathodes of the diodes 30 33. Other 7 il same conclusions combined} i points of the connection 34 and 35,

The openings of the two-stroke B11G1r M1 push-pull are midpoints 36 and 37 of windings 23 and 24 and the connection points 34 and 35 of diodes 30-33 are connected in parallel to the corresponding basic pe: - to sources and 22 in the direction of the power of transistors 1 and

Inrtor works as follows.

The master oscillator 13 generates an alternating voltage of a regular angular shape (Fig. 2a), which receives modular 12 and transforms into a PIR-modulated impulse voltage ((gig. 36), duration imphm h hto.) 1m- (change Depending on the magnitude of the control voltage, a feedback amplifier 11 is connected to the output of the inverter.

In the generation process at time t, the voltages on the windings 14, 15, 23, and 24 of transformers 16 and 25 are polarity corresponding to the depicted signs and - in Fig. 1 without brackets. In this case, the control voltage (to the base) of the transistor 1 in the time interval receives the unlocking voltage (Fig. 2c). Transistor 1 is open because the rectifier on diodes 30 and 31 is locked by the voltage across the resistor 21 created by the base current of transistor 1 flowing through it, meaning the condition under which the voltage on the windings 14 and 15 of the transformer of the modulator 12 must be equal to or more voltages on the semi-windings of the windings 23 and 24 of the transformer of the master oscillator 13.

The output voltage of the rectifier on the diodes 32 and 33 coincides in phase with the voltage of the winding 15 (indicated by signs without brackets) and is applied in the blocking direction to the control side of the transistor 2. The load current flows from the upper (according to the circuit bie) from the power source 3 through the transistor 1, through the winding 4 of the power transformer 5, charge the capacitor 7, to another terminal of the power supply. On the primary winding 4 of the power transformer 5, an alternating voltage occurs, which is similar in shape to that shown in FIG. 26. In the intervals t, - t, t 5 - t, tj - t, the drive voltage across the transistor 1 is zero (Fig. 2e), the transistor 2 is closed at these intervals (fig.2g) and the voltage on its collector is the voltage of the power source 3, In the time interval t, the voltage on the windings 14 and 15 of the Transformer 16 of the modulation unit is zero (Fig. 2b). In this case, the resistors 21 and 22 act on the output voltages formed by the diodes 30 and 31, 32 and 33 of the capacitors, which are locked to the control inputs of the power transistors 1 and 2 through the neutral windings 14 and 15. Both power transistors are locked and on the collectors the same voltage is valid, equal to half the voltage of the power supply source 3, since the transistors are connected in series between its poles (Fig. 2e, e),

In the time interval

Fr anzistor 2 opens (Fig. 2d, f) and then the switching process in the inverter repeats as described.

Thus, in all intervals (Fig. 2b), where there is a pause between control pulses from the modulation unit 12, a voltage appears on the resistors 21 and 22, which is always directed in the closing polarity with respect to the power control inputs transistors 1 and 2.

Claims (1)

In the proposed inverter, pulse width modulator operation is symmetric in half periods. Invention Formula Adjustable half bridge inverter containing two according to after 276966 connecting power transistors, a control unit for the output pulse transformer of a pulse width pulse cell, having two secondary windings, and an output transformer of the master oscillator, also having two secondary windings and rectifying diodes, each with a secondary winding of the output transformer of the pulse pyrin modulator transformer connected to the input power transistor through the base resistor. ten It is distinguished by the fact that, in order to increase reliability by providing pulse width modulator operation that is symmetric over half-periods, the rectifying diodes are connected according to the scheme of two separate full-wave drives, the input of each of which is connected to the secondary winding of the output transformer of the secondary generator, and the output the base resistor in the direction of blocking the power transistor, 2 Фцг.З