Patent ID: 7091671

Claim:
A rail voltage switching circuit for an electronic ballast comprising: a mains power supply ( 200 ), the mains power supply ( 200 ) providing mains power ( 210 ) and a mains voltage signal ( 212 ); a ballast microcontroller ( 206 ), the ballast microcontroller ( 214 ) being responsive to the mains voltage signal ( 212 ) and generating a power factor correction (PFC) voltage signal ( 214 ); and a converter ( 204 ), the converter ( 204 ) being operably connected to the mains power supply ( 200 ) and being responsive to the PFC voltage signal ( 214 ) to generate a DC rail voltage output ( 208 ), the DC rail voltage output ( 208 ) being a first DC rail voltage output if the mains power ( 210 ) is within a first mains voltage range and a second DC rail voltage output if the mains power ( 210 ) is within a second mains voltage range.