HF multiresonant electronic ballast for fluorescent lamps with constant filament preheat voltage

Abstract

Abstract-A novel HF multiresonant ballast for fluorescent lamps is analyzed, simulated, and tested experimentally. The ballast includes two major resonant networks. The lamp is driven by a parallel resonance arrangement that acts as a current source. During warm-up the filaments are driven by a secondary winding of a series-resonant inductor. The series resonance branch, which is active during warm-up, feeds the filament and shorts out the voltage across the lamp. Simulation and experimental results suggest that the inherent features of the proposed ballast topology will prolong lamp life.Index Terms-Electronic ballast, fluorescent lamps, resonant inverter, SPICE simulation.

Electronic Ballast Ic With Adjustable Preheat Time and Minimum Frequency for Hot Fluorescent Lamp

“…The°u orescent lamp with the preheating starting is often called hot cathode°uorescent lamp and it's lamp life is strongly dependent on the¯laments' conditions during the preheating, ignition and normal operation. 1,6,7 It is generally recognized that correct lament preheating and lamp ignition processes are dominant factors in the design of high quality electronic ballasts. Some basic requirements for an adequate lamp operation are presented as following:…”

“…6,7 The current source utilizes the constant current passing though the resonant inductor to preheat the lamp¯lament. And during this preheating time, some techniques must be used to keep the voltage across the lamp lower than the ignition voltage.…”