Gas discharge lamp drive circuit e.g. for emergency lighting, includes control circuit designed to operate load circuit with lamp at start of preheating phase at different frequencies

摘要

A circuit arrangement (1) for driving a gas discharge lamp (LA) includes a terminal for the lamp and a load circuit (2) containing a resonance circuit and a control circuit (5,6). The control and/or regulating circuit is designed such that the load circuit (2) operates with the lamp (LA) to start a preheating phase a different frequencies. The power uptake of the load circuit (2) is detected depending on the respective frequency and on the basis of the measured results, determines a preheating frequency (fheat) and during the preheating frame, drive the load circuit (2) with the lamp (LA) at the preheat frequency (fheat).