Patent ID: 7259523

Claim:
Circuit arrangement for igniting and operating a lamp comprising input terminals for connection to a supply voltage source, a DC-AC-converter coupled to the input terminals and equipped with a series arrangement comprising a first and a second switching element and connecting the input terminals, a control circuit, coupled to respective control electrodes of the first switching element and the second switching element, for generating a periodic control signal for alternately rendering the first switching element and the second switching element conductive and non-conductive, a load circuit shunting one of the switching elements and comprising a series arrangement of an inductive element and a first capacitive element, characterized in that the control circuit is equipped with a first signal generator coupled to one of the switching elements for generating a first signal that represents the integral of a current that has flowed in forward direction through said switching element in the present period of the control signal, a second signal generator coupled to the first singal generator for generating a first reference signal that represents a desired value of the integral of the current flowing in forward direction through said switching element in each period of the control signal, a switching circuit coupled to the first signal generator, to the second signal generator and to a control electrode of the switching element coupled to the first signal generator, for rendering the switching element non-conductive, when the first signal equals the first reference signal.