Patent ID: 8643284

Claim:
A circuit for driving a LED assembly comprising at least one LED illumination device, the circuit comprising a switch, an inductor, in a series connection with the switch, the switch to in a closed state thereof charge the inductor and in an open state thereof allow the inductor to discharge, a current measurement element to measure a current flowing through at least one of the inductor and the LED illumination device in the open and closed state of the switch, the switch, inductor and current measurement element being arranged to establish in operation a series connection with the LED illumination device, the circuit further comprising: a comparator to compare a signal representing the current measured by the current measurement element with a reference, an output of the comparator being provided to a driving input of the switch for driving the switch from one of an open and a closed state of the switch to the other one of the open and the closed state of the switch upon a change of an output state of the output of the comparator.