System and method for over voltage protection in both positive and negative polarities

摘要

A system and method of protecting measurement circuits from a potentially energized device under test (DUT). In one embodiment, the DUT is a capacitor that has acquired a charge though some means prior to needing to test it. In this embodiment, a circuit is provided that protects the measurement circuit by both limiting the current to the measurement circuit while simultaneously dissipating the energy stored in the DUT. In a further embodiment, a detection circuit is provided to measure the voltage at the terminal of the DUT. Only when the magnitude of the voltage is lower than a specific threshold will the measurement circuit be switched to and connected with the DUT.