Patent ID: 7154227

Claim:
A circuit arrangement for operating at least one light source comprising: a rectifier (D 7 , D 8 , D 9 , D 10 ) having a system voltage input (J 1 , J 2 ) which provides a rectified system AC voltage at a positive (POS) and a negative rectifier output (NEG) when a system AC voltage having a system frequency is applied to its system voltage input; a first diode (D 1 ) which is coupled with its anode to the positive rectifier output (POS) and with its cathode to a positive rail (DCP); a negative rail (DCN) which is coupled to the negative rectifier output (NEG); a second (D 3 ), a third (D 4 ), a fourth (D 5 ) and a fifth diode (D 6 ) which are connected in series between the positive (DCP) and the negative rail (DCN), in each case the cathode of these diodes (D 3 , D 4 , D 5 , D 6 ) pointing towards the positive rail (DCP), and the junction points of these diodes (D 3 , D 4 , D 5 , D 6 ) forming the following nodes: a first node (N 1 ) between the second (D 3 ) and the third diode (D 4 ), a second node (N 2 ) between the third (D 4 ) and the fourth diode (D 5 ), and a third node (N 3 ) between the fourth (D 5 ) and the fifth diode (D 6 ); a first (C 1 ) and a second storage capacitor (C 2 ), the first storage capacitor (C 1 ) being connected between the positive rail (DCP) and the first node (N 1 ), and the second storage capacitor (C 2 ) being connected between the negative rail (DCN) and the third node (N 3 ); an inverter (T 1 , T 2 ) which is connected to the positive (DCP) and the negative rail (DCN) for power supply purposes and provides an inverter output voltage (U OUT ), which has an inverter oscillating frequency which is substantially higher than the system frequency, at an inverter output (OUT) opposite the negative rail (DCN); a reactance network which is connected to the inverter output (OUT) and provides output terminals (J 3 , J 4 ) for the purpose of connecting the at least one light source, the reactance network comprising a lamp inductor (L 1 ) which has a first and a second connection, and the first connection being coupled to the inverter output (OUT); a pump capacitor (C 3 ) which is coupled between the second node (N 2 ) and the positive rectifier output (POS), a coupling between the reactance network and the second node (N 2 ) which brings about a voltage waveform, which has the inverter oscillating frequency, at the second node (N 2 ) opposite the negative rail (DCN), characterized in that a phase-shifting device (L 2 ) is connected into the coupling between the reactance network and the second node, the phase-shifting device (L 2 ) being designed to bring about a lead of more than 90° or a lag of the phase between the coupling point in the reactance network and the second node (N 2 ).