Circuit for protecting a load circuit from initial power supply voltage transients

Claim 1

IN AN ELECTRIC CIRCUIT HAVING POSITIVE AND NEGATIVE INPUT TERMINALS CONNECTED TO A UNIDIRECTIONAL VOLTAGE SOURCE AND POSITIVE AND NEGATIVE OUTPUT TERMINALS CONNECTED TO A LOAD CIRCUIT, THE COMBINATION COMPRISING A CONTROLLED RECTIFIER HAVING AN ANODE ELECTRODE, CATHODE ELECTRODE, AND A CONTROL ELECTRODE, SAID ANODE AND CATHODE ELECTRODES CONNECTED BETWEEN SAID NEGATIVE INPUT AND OUTPUT TERMINALS WITH SAID CATHODE ELECTRODE BEING CONNECTED TO THE SAID NEGATIVE INPUT TERMINAL AND SAID ANODE ELECTRODE BEING CONNECTED TO SAID NEGATIVE OUTPUT TERMINAL, SAID POSITIVE INPUT AND OUTPUT TERMINALS BEING CONNECTED TO A COMMON POINT, FIRST AND SECOND RESISTORS CONNECTED SERIALLY BETWEEN SAID POSITIVE AND NEGATIVE INPUT TERMINALS, SAID FIRST RESISTOR BEING CONNECTED TO SAID NEGATIVE INPUT TERMINAL AND SAID SECOND RESISTOR BEING CONNECTED TO SAID POSITIVE INPUT TERMINAL, THE CONTROL ELECTRODE OF SAID CONTROLLED RECTIFIER BEING CONNECTED TO THE JUNCTION BETWEEN SAID FIRST AND SECOND RESISTORS, AND A CAPACITOR CONNECTED IN A PARALLEL CIRCUIT RELATIONSHIP WITH SAID FIRST RESISTOR, THE VALUES OF RESISTANCE AND CAPACITANCE OF SAID FIRST AND SECOND RESISTORS AND CAPACITOR BEING SELECTED SO THAT A SIGNAL OF SUFFICIENT MAGNITUDE TO CAUSE SAID CONTROLLED RECTIFIER TO SWITCH FROM ITS BLOCKING STATE TO A CONDUCTING STATE IS APPLIED TO THE CONTROL ELECTRODE OF SAID CONTROLLED RECTIFIER A PREDETERMINED TIME AFTER SAID UNIDIRECTIONAL VOLTAGE SOURCE IS APPLIED TO SAID POSITIVE AND NEGATIVE INPUT TERMINALS.