Driver for high efficiency LED based on flyback stage with current mode control for emergency lighting system

Nowadays, permanent emergency lighting systems (PELS) are widely used in many applications: emergency exit indication, lighting in critical or strategic points. Limitation in operation hours in classical lamps (10.000-20.000 hours for fluorescent lamps) implies short lamp replacement times and, therefore, high maintenance costs. This paper shows a driver based on a flyback circuit for a PELS system. Control in current mode operation assure current constant in LED´s in any battery condition. The long operation life (above 100.000 hours) of high efficiency LED´s with a very simple electronics circuitry implies an interesting solution for this type of applications. A 30 lumens and 1 hour PELS has been built and tested.