Monitoring device for detecting faults in an electrical device

Abstract From the Canadian patent

A monitoring device connected to an LC filter circuit for determining the occurrence of faults therein includes sensors for measuring the voltage drop across the LC filter circuit and the current flow therethrough. The monitoring device includes simulation circuits for estimating the voltage drop and current flow in response to the actual values of the current flow and voltage drop respectively. In, one position of a double-throw switch the actual value of the, current is compared with an estimated value thereof while in another position of the double-throw switch an estimated, value of the voltage drop is compared with the actual value thereof. Differences between the compared values are …