A grounding monitoring device

Abstract

A grounding monitoring device is disclosed herein. In a described embodiment, the grounding monitoring device comprises a wrist strap comprising a first conductive portion for providing a first discharge path between a human arm and a ground; and a second conductive portion electrically isolated from the first conductive portion for providing a different second discharge path between the human arm and the ground. The grounding monitoring device further comprises a bipolar control voltage generator for applying a first voltage at a frequency f0 to the first conductive portion and an opposite second voltage at the frequency f0 to the second conductive portion; and an electrical circuit for: receiving a first total signal from the first conductive portion; receiving a second total signal from the second conductive portion; and forming an output signal based on a differential and common mode gains of the electrical circuit. The grounding monitoring device further comprises a comparator for comparing a portion of the output signal that corresponds to the frequency f0 with a first threshold value; and comparing a portion of at least one of the first total signal and the second total signal that corresponds to the frequency f0 with a second threshold value; wherein an alarm signal is activated depending on the comparisons made by the comparator.

Dependencies are inferred from the claim text.