Patent ID: 6282105
Filing Date: 2001-08-28
Classification: H02M,H05B,Y02B

Abstract:
A device for feeding a group of discharge lamps connected to a lighting network from an AC distribution network, said circuit comprising at least one central unit having an input connected to said distribution network, and an output connected to said lighting network, a diode bridge connected to said input, and at least to a transformer converter which converts the rectified voltage generated by the bridge to a DC voltage applied to said lighting network while providing a galvanic isolation between said input and said output, said transformer converter comprising a primary circuit fed by said bridge and having a switching means controlled by a control unit so as to apply in a primary winding to the transformer a high-frequency AC current, and a secondary circuit comprising a secondary winding of the transformer which is connected to said output through a rectifier circuit, said control circuit comprising means for adjusting said frequency according to one of a plurality of reference values, each corresponding to a power to be delivered at said output, said windings being calculated so that in the entire range used, the switching means moves on conduction with a zero current and therefore, the transformer converter delivers on each switching cycle of the switching means a constant energy independent from a downstream condition of the lighting network.