Patent ID: 7053561

Claim:
A circuit for operating a discharge lamp (LA), the circuit comprising: an inverter (T 1 ,T 2 ) for supplying the lamp with alternating current, the inverter having an operating frequency, the inverter comprising: at least one transistor switching unit (T 2 ) having a gate; and a current limiting device (T 3 ,D 1 ,D 2 ,D 3 ,C 3 ) coupled to the gate of the at least one transistor switching unit (T 2 ), wherein the current limiting device is operable to switch the at least one transistor unit on and off as a function of a current flowing through the at least one transistor unit; a load circuit (L 1 -A,C 1 ,C 2 ) connected between the inverter and the lamp, the load circuit having a resonant frequency; and a phase setting device (R 2 ,C 2 ,L 2 ) connected to the gate of the at least one transistor switching unit (T 2 ), the phase setting device being operable to match the operating frequency of the inverter to the resonant frequency of the load circuit.