Patent ID: 7688562

Claim:
A monitoring device for monitoring a load current flowing to terminals of an electrical device and controlling said electrical device in response to an input from a controller, said monitoring device comprising: (a) a switch to enable a current flow to said electrical device in response to a first input from a controller remotely located from said monitoring device and to disable said current flow to said electrical device in response to a second input from said controller; (b) a transformer magnetically coupled to a conductor of said load current and producing a transformer signal indicative of a magnitude of said load current flowing in said conductor wherein said transformer and said switch are proximate one another; (c) a rectifier to convert said transformer signal to a rectified transformer signal; and (d) a sensing circuit including an amplifier proximate said transformer and said switch, said sensing circuit operable to convert said rectified transformer signal to a state of one of a control signal and a circuit condition communicable to said controller, power for operating said sensing circuit being obtained from said first input of said controller, said first input electrically separated from said conductor of load current; said switch, said transformer, and said sensing circuit all located in a single housing, said first input and said second input not responsive to said state of said one of said control signal and said circuit condition.