Patent ID: 8461774

Claim:
A circuit for powering at least one light source, comprising: a rectifier circuit having AC input terminals to receive AC input power and first and second DC output terminals to provide rectified DC power; an EMI filter circuit having first and second filter input terminals coupled with the DC output terminals of the rectifier circuit and first and second filter output terminals, the EMI filter circuit comprising: a filter capacitance with a first terminal coupled with the first DC output terminal of the rectifier circuit, a field effect transistor, comprising: a first source/drain terminal coupled with a second terminal of the filter capacitance, a second source/drain terminal coupled with the second DC output terminal of the rectifier circuit, and a gate terminal coupled with the second DC output terminal of the rectifier circuit, and an inductance with a first terminal coupled with the first DC output terminal of the rectifier circuit, and a second terminal coupled with the first filter output terminal; and a power converter circuit, comprising at least one DC to DC converter circuit with DC input terminals coupled with the filter output terminals ( 102 a , 102 ), the power converter circuit operative to directly or indirectly provide power to at least one light source.