| 摘要 |
1. A system for extracting the energy induced by a capacitive coupling in a guard wire (F) by the conductors of an AC transmission line, said system having an output and comprising a voltage step-down device (T, T1 ) for transforming said energy induced in the guard wire (F) into an output AC voltage, and regulation means for regulating said output AC voltage, said regulation means being mounted in shunt between said voltage step-down device (T, T1 ) and said output and comprising a switching circuit (TR, CM) coupled to the voltage step-down device (T, T1 ), characterized in that said switching circuit (TR, CM) operates in one and the other possible voltage polarities and said regulation means further comprises : - an inductance (L) serially mounted between the switching circuit (TR, CM) and the voltage step-down device (T, T1 ) for reversing the voltage polarity and blocking the switching circuit (TR, CM) after it has been fired in one polarity until it is fired in the other polarity, and - a control circuit (CT, CL) responsive to the polarity and amplitude of the output AC voltage for selectively controlling the firing of the switching circuit (TR, CM), said control circuit (CT, CL) comprising means responsive to the phase of the output AC voltage and the polarity of the switching circuit (TR, CM) for firing said circuit alternatively in one polarity and in the other. |
