| 摘要 |
A circuit ( 200 ) for powering a high intensity discharge lamp ( 10 ) comprises first and second input terminals ( 202,204 ), first and second output terminal ( 206,208 ), first and second inverter switches (SW<SUB>1</SUB>,SW<SUB>2</SUB>), a transformer ( 240 ), first and second buck capacitors (C<SUB>BUCK1</SUB>,C<SUB>BUCK2</SUB>), first and second low-side capacitors (C<SUB>LOWSIDE1</SUB>,C<SUB>LOWSIDE2</SUB>), an ignitor ( 216 ), and a diode subcircuit ( 250,260 ). Transformer ( 240 ) includes a primary winding ( 242 ) and a secondary winding ( 244 ). During operation of circuit 200 , primary winding ( 242 ) functions as a buck inductor, while secondary winding ( 244 ) operates in conjunction with diode subcircuit ( 250,260 ) to provide enhanced low frequency open circuit voltage (OCV) during the lamp starting phase and during steady-state powering of the lamp ( 10 ). Circuit ( 200 ) also allows for a lamp current having a non-zero average value. Circuit ( 200 ) is realizable with first and second low-side capacitors (C<SUB>LOWSIDE1</SUB>,C<SUB>LOWSIDE2</SUB>) having a relatively low capacitance value. |
