Transistor clamp circuit

Claim 1

IN A CIRCUIT FOR CORRECTION OF A SIGNAL SUPPLIED FROM A SOURCE AND HAVING RECURRENT CONTROL PERIODS, THE COMBINATION INCLUDING, UTILIZATION MEANS FOR SAID CORRECTED SIGNAL, A FIRST CAPACITOR CONNECTED BETWEEN SAID SOURCE AND SAID UTILIZATION MEANS, AN INSLUATED-GATE FIELD-EFFECT TRANSISTOR HAVING SOURCE DRAIN AND GATE ELECTRODES ON A SUBSTRATE OF SEMICONDUCTOR MATERIAL A CHARGING AND DISCHARGING CIRCUIT FOR SAID CAPACITOR, SAID CIRCUIT BEING CONNECTED BETWEEN SAID UTILIZATION MEANS AND A POINT OF REFERNECE POTENTIAL FOR SAID CIRCUIT AND INCLUDING THE DRAIN-SOURCE PATH OF SAID TRANSISTOR, SAID DRAIN-SOURCE PATH COMPLETING A CHARGING CIRCUIT FOR SAID CAPACITOR WHEN THE POTENTIAL DIFFERENCE BETWEEN THE POTENTIAL OF SAID UTILIZATION MEANS AND SAID REFERENCE POTENTIAL IS OF ONE POLARITY DURING A CONTROL PERIOD PORTION, AND SAID DRAIN-SOURCE PATH COMPLETING A DISCHARGING CIRCUIT FOR SAID CAPACITOR WHEN SAID POTENTIAL DIFFERENCE IS OF THE OPPOSITE POLARITY TO SAID ONE POLARITY DURING A CONTROL PERIOD PORTION. MEANS PROVIDING A SOURCE OF KEYING SIGNALS COUPLED THROUGH A SECOND CAPACITOR TO SAID GATE ELECTRODE FOR RENDERING SAID DRAIN-SOURCE PATH CONDUCTIVE DURING AT LEAST A PORTION OF EACH OF SAID CONTROL PERIODS, AND MEANS DIRECT CURRENT CONDUCTIVELY CONNECTING SAID GATE ELECTRODE TO SAID SUBSTRATE.