Apparatus for determining conformity of resistance value to percentage tolerance limits

Claim 1

APPARATUS FOR DETERMINING THE CONFORMITY OF THE OHMIC VALUE OF A RESISTOR UNDER TEST TO THE RATED VALUE THEREOF WITHIN A PERCENTAGE TOLERANCE LIMIT COMPRISING: A SOURCE OF ELEECTRICAL POWER; A FIRST VARIABLE RESISTOR HAVING A PREDETERMINED BASE VALUE; MEANS FOR CONNECTING SAID FIRST RESISTOR IN SERIES WITH THE RESISTOR UNDER TEST AND FOR CONNECTING SAID FRIST AND TEST RESISTORS ACROSS THE OUTPUT OF SAID POWER SOURCE; A SECOND RESSISTOR HAVING AN OHMIC VALUE EQUAL TO SAID RATED VALUE TIMES A PREDETERMINED FACTOR; A THIRD RESISTOR HAVING AN OHMIC VALUE SUBSTANTIALLY EQUAL TO THE ALGEBRAIC SUM OF SAID BASE VALUE AND THE PRODUCT OF SAID BASE VALUE AND SAID TOLERANCE PERCENTAGE; MEANS CONNECTING SAID SECOND AND THIRD RESISTORS IN SERIES ACROSS SAID POWER SOURCE; MEANS COUPLED WITH SAID FIRST RESISTOR FOR VARYING THE LATTER TO SET THE RESISTANCE THEREOF AT AN OHMIC VALUE EQUAL TO SAID BASE VALUE DIVIDED BY SAID FASTOR; AND MEANS FOR COMPARING THE VOLTAGE DROPS ACROSS EITHER SAID FIRST AND THIRD RESISTORS, OR SAID SECOND RESISTOR AND THE RESISTOR UNDER TEST.