| 摘要 |
<p>A direct current circuit including a pair of ground electrodes and an electrolytically conductive earth formation therebetween is normally fixedly connected to the high voltage direct current output terminals of a power rectifier. The unidirectional voltage supplied to the terminals through the power rectifier is variable and the power rectifier may be disconnected by control means in its alternating current input circuit. A bias voltage of normal polarity and predetermined low magnitude is supplied to the output terminals by a low voltage battery and blocking rectifier in series circuit relation connected directly across the terminals in opposing relation to the voltage supplied through the power rectifier. Battery charge is maintained through a current limiting impedance of high resistance connected across the blocking rectifier.</p> |
