SU570172A1 - Inverter - Google Patents

Description

(54) INVERTER

asiche connected to the inerto terminal, on which there is a variable april. At the same time, the parameters of the choke switches are so that) its saturation occurs earlier than the change in the polarity of the up-5 most-plus C1 drive | (i.e. it is calculated on a higher frequency). As a result, the base of the power transistor forms a step-shaped current that provides a saturated mode of operation of the transistor Q torus in most of the open half period.

Before the switching moment, the transistor is removed from the saturation mode, and the time of its operation in the active region should be enough to absorb the excess media.

FIG. 1 shows a diagram of an inverter made in the form of a multivibrator transfrmator; in fig. 2 - time 20 voltage and current diagrams .;

The inverter contains an output transformer 1, a power 2.3 and an auxiliary 4.5 transistors forming a composite switch, as well as a saturation choke 6 connected to the output voltage of the converter via a ballast resistor 7.

The base circuit of the composite transistor switches is closed through a resistor 8 and diodes shunt the input junctions of 30 transistors. the opposite direction. The full signals on the circuit correspond to the open state of transistors 2 and 4. And the shertor works as follows. If 35 transistors 2 and 4 are in the open state, then the output voltage is almost completely applied to the throttle of the 6, and, transforming into its additional, -winding, it touches the power transistor 2. The value of 0 on the secondary voltage 1 V , at the same time, it compensates for the voltage drop at the emitter-collector junction of the auxiliary transistor 4 and depletes the shift of the base 1 - collector of the power transistor 2 in the forward direction. A drop in the voltage} e on the junction emitter collector (and ,,) of the power transistor is small, and a current of the collector flows through the base of its base and 60

And, is the power gain factor. current tracing mode

This state is maintained for a large half-period until saturation, droplet 6. When it is saturated, the voltage of not all its windings decreases to zero.

This leads to a change in the polarity of the voltage at the base-collect: p junction of an open power transistor (see fng. 1 signs in circles),. which becomes equal to the papal voltage across the emitter-to-cector transition of the auxiliary transistor. As a result, the power transistor leaves the saturation region, its current gain increases and the base current decreases to a value of 3, // 5, where ft is the current gain in the active region. Thus, by the moment of switching, the corresponding preparation of the transistor takes place, concluding with the removal of excess carriers from the base region even during the open state interval. After a predetermined time, the output of the transformer 1 occurs, which leads to almost instantaneous switching of the transistors of the converter. Thereafter, the processes in the circuit are repeated.

In the converter circuit, there is no pulsed non-growth of the collector current at the end of the half-period, which is characteristic of the Roger oscillator circuit and is its main drawback. As a result, the dynamic losses in the power transistors are significantly reduced, and the reliability of the circuit is increased.

Similarly, you can perform the converter on the bridge circuit.

Claims (2)

1. Kossov O. A. Power amplifiers on transistors in the switching mode, Energie, M., 1971, p. 114-115. 2. Electronic technology in automation, vol. 4, M., 1973, p. 29. -"and - 0 g