| 摘要 |
A method of regulating electrical power supplied via a current path to a consumer in an A.C. network involves setting a desired current flow angle using a power switching device connected in the current path to the consumer. The method includes cutting the switching device ON at the beginning of each half-wave of the line voltage substantially at a phase angle of zero degrees, and cutting the power switching device off at a phase angle corresponding to the desired current flow angle. A power switching device for carrying out the method includes at least one set of two transistors having their respective collector-emitter leads connected in parallel to define a current path. Rectifier means are provided in series with the consuming means and the transistors. Secondary winding means of transformer means are connected in respective base-emitter circuits of the transistors, while primary winding means of the transformer means are connected to a source of switching voltages which drive the transistors. The primary winding means are connected to a source of driving voltage which provide gating ON pulses to the two transistors out of phase but overlapping. The driving voltage includes OFF pulses which include a portion whose polarity is opposite to that of the gating ON pulses.
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