Apparatus for testing conductivity of an unknown impedance and including silicon controlled rectifier detector means

Claim 1

ELECTRICAL TEST APPARATUS FOR DETERMINING THE CONDUCTIVITY ON AN UNKNOWN IMPEDANCE COMPRISING, IN COMBINATION, A SOURCE OF ELECTRICAL POWER, A SELECTIVELY VARIABLE PREDETERMINED IMPEDANCE MEANS, AN UNKNOWN IMPEDANCE MEANS CONNECTED BETWEEN AND IN SERIES WITH SAID SOURCE OF POWER AND SAID PREDETERMINED IMPEDANCE MEANS, A FIRST DETECTOR MEANS HAVING TWO STATES OF CONDUCTION INCLUDING A SILICON CONTROLLED RECTIFIER HAVING AN ANODE, A CATHODE AND A GATE ELECTRODE WHEREIN THE GATE-CATHODE JUNCTION IS CONNECTED IN PARALLEL WITH SAID VARIABLE PREDETERMINED IMPEDANCE MEANS AND BEING RESPONSIVE TO A PREDETERMINED VOLTAGE THEREACROSS FOR CHANGING FROM ONE STATE OF CONDUCTION TO ANOTHER STATE OF CONDUCTION AND FURTHER HAVING THE ANODE OF SAID SILICON CONTROLLED RECTIFIER CONNECTED TO SAID SOURCE OF POWER, A SECOND DETECTOR MEANS HAVING TWO STATES OF CONDUCTION AND BEING CONNECTED IN PARALLEL WITH THE ANODE-CATHODE JUNCTION OF SAID SILICON CONTROLLED RECTIFIER OF SAID FIRST DETECTOR MEANS AND BEING RESPONSIVE TO A PREDETERMINED VOLTAGE DROP ACROSS THE ANODE-CATHODE JUNCTION OF SAID SILICON CONTROLLED RECTIFIER FOR CHANGING FROM ONE STATE OF CONDUCTION TO ANOTHER STATE OF CONDUCTION, A TIME DELAY MEANS CONNECTED BETWEEN SAID FIRST AND SECOND DETECTOR MEANS FOR DELAYING FOR PREDETERMINED TIME THE DETECTION BY SAID SECOND DETECTOR MEANS OF THE VOLTAGE ACROSS SAID FIRST DETECTOR MEANS, AND FIRST AND SECOND INDICATOR MEANS CONNECTED TO SAID FIRST AND SECOND DETECTOR MEANS, RESPECTIVELY, TO INDICATE THE STATE OF CONDUCTION OF SAID FIRST AND SECOND DETECTOR MEANS, WHEREBY THE CHANGE IN CONDUCTIVITY OF SAID FIRST DETECTOR INDICATES A FIRST RELATIONSHIP OF SAID UNKNOWN IMPEDANCE TO SAID VARIABLE IMPEDANCE, A CHANGE IN CONDUCTION OF SAID SECOND DETECTOR INDICATES A SECOND RELATIONSHIP OF SAID UNKNOWN IMPEDANCE TO SAID VARISAID FIRST AND SAID SECOND DETECTORS INDICATES A THIRD ABLE IMPEDANCE AND A CHANGE IN CONDUCTION OF BOTH RELATIONSHIP OF SAID UNKNOWN IMPEDANCE OF SAID VARIABLE IMPEDANCE.