Compact Emergency Lamp Using Power LEDs

This paper presents a compact emergency lamp using light-emitting diodes (LEDs). The goal is to develop a compact and low-cost electronic circuit to drive and control the current of LEDs arranged in a single enclosure. The main advantage of the proposed idea is to use the same equipment in the daily activities, supplied by the ac line, and under a mains failure, supplied by a battery. The proposal also aims to achieve energy saving, higher luminous efficacy, and higher useful life when replacing traditional fluorescent-based emergency lighting systems. The use of the E-27 socket provides the advantage of easy installation, with the simple replacement of the lamp without any change in the electrical wiring. Buck and boost converters were employed in order to supply the LEDs by mains and by battery, respectively. However, the converters are designed in order to work without electrolytic capacitors, which have advantages such as reducing size and cost of the circuit, THD reduction, and increasing the useful life of the driver. The battery can be composed of three rechargeable Ni-MH batteries (1.2 V) or a Li-ion battery (3.6 V). The design complies with the Brazilian and international standards for emergency lighting systems and IEC 61000-3-2. The proposed circuit was implemented, and the experimental results were satisfactory.