| 20110298386 | LED LIGHTING FIXTURE WITH ONE SET OF INTENSITY OF LIGHT - A LED lighting apparatus includes at least one LED lighting element, a control unit and a switching converter, for supplying the LED lighting element. A feedback circuit is connected between the LED lighting element and a ground line and co-operates with the switching converter for determining a LED current through LED lighting element. The feedback circuit has a first impedance in a first state, to which a non-zero first regulation value of the LED current corresponds, and a second impedance in a second state, to which a non-zero second regulation value of the LED current corresponds. The control unit is configured to cyclically switch the feedback circuit between the first state and the second state with a controllable duty-cycle. | 12-08-2011 |
