Patent ID: 7880399

Claim:
A ballast for operation of at least one high-pressure discharge lamp, with the ballast having a voltage converter for production of an essentially sinusoidal alternating current, the voltage converter being in the form of a Class E converter which has DC voltage inputs, wherein an inductance and the switch path of a controllable switching means are connected between the DC voltage inputs, and a diode is arranged back-to-back in parallel with the switch path of the controllable switching means, and a capacitance is arranged in parallel with the switch path of said controllable switching means and in parallel with said diode, with the inductance being of such magnitude that it acts as a constant-current source, and a parallel circuit, which is in the form of a series resonant circuit, is provided for said capacitance, to which parallel circuit the at least one high-pressure discharge lamp to be operated is coupled, the current which flows in the closed state via the switch path of said controllable switching means and in the open state via said capacitance being composed of a direct current and a sinusoidal alternating current, which is generated by the series resonant circuit.