Method and apparatus for measuring the forward voltage drop, the for ward leakage current, and the reverse leakage current of a controlled rectifier under dynamic conditions

Claim 1

A METHOD OF DYNAMICALLY MEASURING UNDER PREDETERMINED LOAD CURRENT UP TO RATED LOAD CURRENT THE FORWARD VOLTAGE, DROP THE FORWARD LEAKAGE CURRENT, AND THE REVERSE LEAKAGE CURRENT OF A CONTROLLED RECTIFIER HAVING AN ANODE, CATHODE, AND GATE ELEMENT COMPRISING APPLYING A PERIODIC GATING VOLTAGE BETWEEN GATE ELEMENT AND CATHODE THAT RENDERS THE GATE ELEMENT POSITIVE RELATIVE TO THE CATHODE FOR PART OF EACH PERIOD, DURING THAT PART OF EACH PERIOD THAT THE GATE IS POSITIVE APPLYING A POSITIVE ANODECATHODE VOLTAGE FOR PASSING SAID PREDETERMINED LOAD CURRENT THROUGH SAID CONTROLLED RECTIFIER AND METERING THE RESULTANT FORWARD VOLTAGE DROP FROM ANODE TO CATHODE, APPLYING BETWEEN ANODE AND CATHODE DURING A PREDETERMINED FRACTION OF THE REMAINING PORTION OF EACH GATING PERIOD A POSITIVE VOLTAGE OF PEAK VALUE APPROXIMATELY EQUAL TO THE RATED FORWARD BREAKOVER VOLTAGE AND METERIN THE RESULTANT LEAKAGE CURRENT, AND APPLYING DURING ANOTHER NONOVERLAPPING PREDETERMINED FRACTION OF THE REMAINING PORTION OF EACH GATING PERIOD, A NEGATIVE VOLTAGE OF PEAK VALUE APPROXIMATELY EQUAL TO HE RATED PEAK INVERSE VOLTAGE AND METERING THE RESULTANT LEKAGE CURRENT.