Patent ID: 6577077
Filing Date: 2003-06-10
Classification: H05B,Y02B

Abstract:
A circuit arrangement for operating a lamp, comprisingsupply input terminals for connection to a supply voltage source, a rectifier coupled to the supply input terminals for rectifying an AC supply voltage supplied by the supply voltage source, an inverter equipped with input terminals coupled to respective output terminals of the rectifier for generating a high frequency lamp current out of a DC voltage, a first unidirectional element (D1) coupled between a first output terminal of the rectifier and an input terminal of the inverter, a first branch that is coupled between a terminal (N1) between the first output terminal of the rectifier and the first unidirectional element and a terminal (N2) in the inverter on which during operation of the circuit arrangement a high frequency voltage is present, characterized in that the circuit arrangement is further provided with a second branch comprising a series arrangement of a second (D2), a third (D3), a fourth (D4) and a fifth unidirectional element (D5) that connects the input terminals of the inverter, a third branch comprising a first capacitive element (C1) and connecting a cathode of the second unidirectional element with an anode of the fourth unidirectional element, a fourth branch comprising a second capacitive element (C2) connecting an anode of the fifth unidirectional element with a cathode of the third unidirectional element, a fifth branch connecting a terminal (N5) between the third and the fourth unidirectional element with the terminal (N2) of the inverter.