Patent ID: 7129649

Claim:
A ballast for powering at least one lamp (La), the ballast comprising: at least two switches (S 1 , S 2 ) arranged in series; a control circuit for alternately opening and closing the at least two switches (S 1 , S 2 ); a connection for applying a supply voltage (U 0 ) to the at least two switches (S 1 , S 2 ); a resonant starting circuit coupled on an input side to a junction point between the at least two switches (S 1 , S 2 ) and coupled on an output side to a first connection ( 10 ) for the lamp (La), the resonant starting circuit comprising: a resonant inductance (L 1 ) arranged in series with the junction point between the at least two switches (S 1 , S 2 ) and in series with the first connection ( 10 ) for the lamp (La); a resonant capacitance (C 1 ) arranged for alternating current purposes in parallel with the first connection ( 10 ) for the lamp (La) and a second connection ( 12 ) for the lamp (La); a first braking inductance (L B1 ) which, for alternating current purposes, is firstly arranged in series with the lamp (La) and secondly arranged in parallel with the resonant capacitance (C 1 ); and a second braking inductance (L B2 ) which is arranged in series with the resonant capacitance (C 1 ).