SU474896A1 - Pulse Width Control System - Google Patents

Description

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Pulse-width control systems of thyristor interrupters are known, which contain a blocking geyrator and a non-contact controller, by means of which the inductance of the elements of the pulse generator is changed.

Known control systems are complex and not reliable enough due to the complexity of the conversion of the control signal.

The proposed pulse width control is characterized in that the capacitor of the driving RC generator is enclosed by a series circuit consisting of a diode and two windings located on the same magnetic core as the winding of the blocking generator.

FIG. 1 is a schematic diagram of the proposed system; in fig. 2 - magnetic circuit design; in fig. 3 - diagrams explaining the operation of the scheme.

The control system diagram (see Fig. 1) contains a blocking generator on transistor I, in the collector circuit of which the collector winding 2 of the pulse transformer is turned on, blocked by a diode 3. The base winding 4 of the positive feedback generator charges the capacitor 5, which is overcharged It is passed through the resistance 6. The repetition frequency of the control pulses is determined by the resistance values 6 and

capacitor 5 and remains unchanged. Control pulses are applied to the thyristors from the winding 7. The windings 2, 4, 7 are located on the middle core of the magnetic circuit 8 (see

FIG. 2) pulse transformer. On the leftmost rod, the magnetic resistance of which varies by moving coil 9, is placed the charging winding 10. On the middle core of the magnetic circuit is still placed the bias winding 11 connected in series and oppositely with the charging winding through diode 12 to the capacitor 13 of the RC geerator sawtooth strained Resistance 14 is made to form the back edge of the saw. The voltage on the capacitor 13 in the control system is controlled by the zero-body 15, the output of which is connected to the pulse shaper 16, from which the control pulses are spooled

a shift in relation to nmpu; 1s, generated by a blocking generator. The time shift (within the period T) of both the control pulses L and Lls depends on the level Uc (see Fig. 3) to which the capacitor 13 is charged. This level is determined by the magnetic resistance of the left sterile magnetic circuit, since the charge of the capacitor is carried out from the winding 10 at the time of formation of the pulse by the blocking generator.

In turn, the magnetic resistance he