Patent ID: 8129976

Claim:
A load control circuit for controlling the amount of power delivered to an electrical load from an AC power source for generating an AC line voltage, the load control circuit comprising: a controllably conductive device adapted to be coupled in series electrical connection between the power source and the electrical load, the controllably conductive device having a conductive state and a non-conductive state, the controllably conductive device having a control input and operable to enter the conductive state in response to a gate current conducted through the control input; a sense circuit having an input operatively coupled in series with the control input of the controllably conductive device so as to conduct the gate current, and an output for providing a control signal representative of the magnitude of the gate current; and a controller operable to drive the controllably conductive device to change the controllably conductive device from the non-conductive state to the conductive state each half-cycle of the AC line voltage, the controller coupled to the output of the sense circuit for receiving the control signal representative of the magnitude of the gate current, the controller operable to determine, in response to the magnitude of the gate current through the control input of the controllably conductive device, whether the controllably conductive device is presently conducting current to the load.