Patent ID: 8581507

Claim:
Lighting apparatus comprising: at least one LED lighting element; a control unit; a switching converter, having a supply input, connectable to a supply line for receiving an input supply voltage (V A ), and an output for supplying the at least one LED lighting element; a feedback circuit, connected between a terminal of the at least one LED lighting element and a constant potential line and co-operating with the switching converter for determining a LED current (I L ) through the at least one LED lighting element; wherein the feedback circuit has, in a first state, a first impedance value (R 1 ) between the terminal of the at least one LED lighting element and the constant potential line to which a non-zero first regulation value (I L1 ) of the LED current (I L ) corresponds, and, in a second state, has a second impedance value (R 2 ) between the terminal of the at least one LED lighting element and the constant potential line to which a non-zero second regulation value (I L2 ) of the LED current (I L ) corresponds, and wherein the control unit is configured to cyclically switch the feedback circuit between the first state and the second state with a controllable duty-cycle.