Patent ID: 6552494
Filing Date: 2003-04-22
Classification: H05B

Abstract:
A driver circuit for a fluorescent lamp having a first and a second electrode and igniting when the voltage between said first and second electrodes exceeds a given threshold voltage, said driver circuit comprising:an inductance coupled to a supply voltage and to a terminal of said first electrode; a first condenser coupled to the other terminal of said first electrode and to a terminal of said second electrode; a control device including a first and a second system of switches for providing an oscillating voltage signal to said inductance and to said first condenser for igniting said lamp; and a preheating device for regulating the frequency of said oscillating signal between the resonance frequency of said inductance and said first condenser and a frequency greater than the resonance frequency of said inductance and of said first condenser in order to provide a preheating of said first and second electrodes, said preheating device being sensitive to the depletion of gas of said lamp and being capable of sending a turn-off signal to said control device.