Apparatus for detecting discharges in insulation and for discriminating between suchdischarges and any discharges occurring in termination means carried by such insulation

Claim 1

APPARATUS FOR DETECTING DISCHARGES IN INSULATING MEANS AND FOR DISCRIMINATING BETWEEN SUCH DISCHARGES AND ANY DISCHARGES WHICH MAY OCCUR IN TERMINATION MEANS CARRIED BY SUCH INSULATING MEANS, SAID APPARATUS COMPRISING A BLOCKING CAPACITOR AND INDUCTANCE MEANS CONNECTED TO EACH OTHER, MEANS FOR CONNECTING A SOURCE OF ALTERNATING CURRENT ACROSS BOTH SAID CAPACITOR AND SAID INDUCTANCE MEANS, MEANS FOR CONNECTING ONE OF SAID INSULATING AND SAID TERMINATION MEANS ACROSS SAID SOURCE IN PARALLEL WITH BOTH SAID CAPACITOR AND INDUCTANCE MEANS TO FORM THEREWITH A TUNED CIRCUIT, MEANS FOR CONNECTING THE OTHER OF SAID INSULATING AND TERMINTION MEANS IN SAAID TUNRED CIRCUIT IN PARALLEL WITH SAID CAPACITOR BUT IN SERIES WITH SAID INDUCTANCE MEANS, WHEREBY A WAVE FORM RESULTING FROM A DISCHARGE IN SAID INSULATING MEANS APPROACHES SAID INDUCTANCE MEANS FROM ONE DIRECTION, BUT ONE RESULTING FROM A DISCHARGE IN SAID TERMINATION MEANS APPROACHES SAID INDUCTANCE MEANS FROM THE OPPOSITE DIRECTION, A FILTER AND AMPLIFYING CIRCUIT CONNECTED ACROSS SAID INDUCTANCE MEANS TO RECEIVE THEREFROM AND ELECTRIC SIGNAL, FILTER OFF A PREDETERMINED BAND OF FREQUENCIES, AND AMPLIFY THE REMAINING COMPONENTS WITHIN THE PASSBAND OF THE FILTER, AN INDICATOR CONNECTED TO BE SUPPLIED WITH A SIGNAL BY SAID FILTER AND AMPLIFYING MEANS AND SWITCH MEANS IN THE ELECTRICAL PATHWAY BETWEEN SAID SOURCE AND SAID INDICATOR CONNECTED TO REVERSE THE POLARITY OF THE SIGNAL SUPPLIED TO SAID INDICATOR.