Patent ID: 8228054

Claim:
A test device, comprising: a first test lead; a second test lead, the first and second test leads configured to receive an input voltage applied across the first and second test leads; an output voltage generator having a first input coupled to the first test lead, a second input coupled to a first fixed voltage, a first output coupled to the second test lead, and a second output coupled to a second fixed voltage, the output voltage generator configured to provide to the second test lead and the first output of the output voltage generator a voltage having a magnitude corresponding to a difference between the magnitude of the first fixed voltage and the magnitude of the input voltage; a processing circuit coupled to the first and second outputs of the output voltage generator, the processing circuit configured to provide an output signal indicative of a voltage across the first and second outputs of the output voltage generator; and a display coupled to receive the output signal from the processing circuit and configured to provide a visual display indicative of the magnitude of the output signal.