A driving technology for retrofit LED lamp for fluorescent lighting fixtures with electronic ballasts

A driving technique that can operate with electronic ballasts for fluorescent lamps to drive light emitting diodes (LEDs) without requiring the replacing of any electronic ballast circuitry or modifying the existing infrastructure of a lighting network is presented. This technology provides an eco-friendly and immediate solution to turn a lighting system with fluorescent lamps into the one with LED lamps. The proposed technology is based on controlling the input impedance of an ac/dc converter, which is connected to the output of the ballast, and converting the high-frequency ac power from the ballast into dc power for the LEDs. An experimental LED lamp prototype for retrofitting 36 W T8 fluorescent lamp has been built.