Patent ID: 8232737

Claim:
An electronic ballast for operating a lamp in a recessed can fixture, the electronic ballast comprising: an input coupleable to an AC power source; an output coupleable to at least one lamp; a ballast circuit operative AC electrical input power from the input and to provide AC output power to the output to drive the at least one lamp; at least one terminal coupleable to a resistive heating element of an insulation detector associated with the fixture; and a regulated current source/sink circuit coupled with the terminal and operative to receive AC electrical power from the input and to provide a regulated amount of heating current to power the resistive heating element, the regulated amount being independent of a voltage of the input power; wherein the regulated current source/sink circuit comprises a linear mode switching device coupled to the at least one terminal in series with the resistive heating element and a first regulator circuit controlling an impedance of the switching device according to a first reference voltage.