Evaluation of a low cost permanent emergency lighting system based on high efficiency LEDs

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 (10000-20000 hours for fluorescent lamps) implies short lamp replacement times and, therefore, high maintenance costs. This paper shows an alternative solution based on high efficiency LED´s. The long operation life (above 100000 hours) of high efficiency LEDs with a very simple electronics circuitry implies an interesting solution for this type of application. A 30 lumens and 1 hour PELS has been built and tested. A low cost power supply has been built and used as battery charger and LED driver.