Patent ID: 7479741

Claim:
A device for lighting at least one light emitting diode (LED) to be supplied with predefined minimum forward voltage and maximum current, comprising: a battery having a voltage less than said predefined minimum forward voltage for supplying voltage to the light emitting diode, a pulse generator for generating a cyclic pulse signal having predefined on-times and off-times, a switch controlled by the pulse generator to be turned on during said on-times to short-circuit the light emitting diode and turned off during said off-times, an inductive device for being charged when the switch is turned on and for increasing the forward voltage over the light emitting diode when the switch is turned off, wherein the pulse generator is a pulse width modulation generator, wherein the inductive device is a coil having an inductance defined by the number of light emitting diodes and maximum current and voltage requirements of said light emitting diodes and available frequency of the pulse generator.