SU373879A1 - MAGNETIC TRANSISTOR KEY - Google Patents

Description

one

The invention relates to the field of converter technology and can be used in static converters, voltage regulators, voltage switches of brushless DC-DC motors, etc.

Magnetic transistor switches connected via a rectifier to a source of signals are known.

In the proposed vein, in order to reduce the weight and dimensions of the circuit, (Current travsformators are introduced, the primary windings of which are connected in series to the output circuit of the transistor, and the secondary windings in antiphase with the primary windings are included in the corresponding rectifier circuits.

The scheme works as follows.

The voltage of the winding / transformer 2 of the master oscillator through the secondary winding 3 of the transformer 4 and the diode 5 of the rectifier is fed to the input of the transistor 6. The winding operates in the current limiting mode of the transistor base, since the primary winding 7 of the current transformer 4 is connected to the output circuit of the transistor. Through this winding

3 current flows, 1, -, where / k -

TO

the collector current of the transistor 6 and K is the transformation ratio of the windings 5 and 7. The voltage on the winding 3 is equal to:

UW, UW, UD, -U ,,,

At the first moment after changing the polarity on the windings of the transformer 2, the core of the current transformer 8 is supersaturated for the current flowing into the beginning of the winding 9. Therefore, a voltage equal to

ten

Uw., Uw ,, + UD. + U.6.,

four

and through it flows current / w, o -, where

TO

Uw, - voltage across the winding //. The voltage / dGD is much larger than Vw, (L; 6 times), therefore the core of the transformer 8 is saturated in 1/6 of the half-period of the supply voltage (see Fig. 1).

Until saturation of the core of the transformer 8 through the base of transistor 6 theorem. t 4 tically flows a current equal to / G -

i.e.

TO

2 times the required (K is equal to p of the transistor), but since practically because of the inductances of the dissipation in the windings 1 - 3, the current in them gradually increases, and because of the not perfect square of the cores of the current transformers, the current in the winding W starts decrease until the core is fully saturated, the total base current of the transistor looks like that shown in Fig. 2

The proposed scheme ensures the proportionality of the current-base to the collector current of the transistor, the best mode of operation of the transistor and allows a significant reduction in the size and weight of such transformers independently of the switching frequency of the power transistor.

Subject invention

A magnetically-transistor switch connected via a transmitter to a signal source, characterized in that, in order to reduce the weight and dimensions of the circuit, current transformers are introduced, the primary windings of which are connected in series in the output circuit of the transistor, and the secondary windings in antiphase with the primary ones, they are included in the corresponding, and their chains are higher.

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