Patent ID: 7656670

Claim:
An electronic ballast, comprising: a first housing; a second housing; an AC/DC converter; a DC bus operably connected to the AC/DC converter; a lamp driver operably connected to the DC bus; a storage capacitor operably connected to the DC bus with capacitor wires; and a filter electrically connected between the DC bus and the capacitor wires, the filter being disposed at the first housing, wherein the AC/DC converter, the DC bus, and the lamp driver are disposed in the first housing; the storage capacitor is disposed in the second housing; and the first housing is thermally isolated and physically separated from the second housing; and wherein the filter comprises: a filter capacitor; a differential mode EMI coil; and a common mode EMI coil, the common mode EMI coil having a first EMI coil magnetically coupled to a second EMI coil; wherein the filter capacitor is connected in parallel across the DC bus; the differential mode EMI coil and the first EMI coil are connected in series between a first side of the DC bus and a first conductor of the capacitor wires; and the second EMI coil is connected in series between a second side of the DC bus and a second conductor of the capacitor wires.