Patent ID: 8564919

Claim:
A method of detecting an overcurrent condition in a dimmer circuit for controlling power delivered to a load, the dimmer circuit having a first switch for controlling the power to the load in a first polarity, the first switch having a first anti-parallel diode, and a second switch for controlling power to the load in a second polarity, the second switch having a second anti-parallel diode, the method comprising: sensing a voltage drop across one of the first or second anti-parallel diodes, whichever is associated with a non-controlling one of the first switch or the second switch; comparing the sensed voltage drop with a reference voltage using a transistor, wherein the reference voltage is temperature compensated to compensate for thermally dependent forward bias voltage drop associated with the transistor and the first or second anti-parallel diodes; and determining that there is an overcurrent condition when the sensed voltage drop exceeds the reference voltage.