Patent ID: 6504318
Filing Date: 2003-01-07
Classification: H05B

Abstract:
A supply coupling of a fluorescent lamp comprising a supply transformer (T1), a resonance circuit comprising a secondary coil (N2) of the transformer (T1) and a capacitor (C1) connected in parallel with the secondary coil (N2), and a fluorescent tube (Lamp1) connected in parallel with the resonance circuit and comprising fluorescent cathodes (F1, F2), the coupling further comprising a direct-current supply (DC) arranged to supply direct current (IDC) through a circuit comprising the first fluorescent cathode (F1) of the fluorescent tube, the secondary coil (N2) of the supply transformer (T1), the second fluorescent cathode (F2) of the fluorescent tube (Lamp1) and an indicator circuit (A) arranged to detect the presence of said direct current (IDC) and to generate a signal indicating that presence to be used for controlling the coupling device of the fluorescent lamp.