Characteristics of electrodeless ferrite-free fluorescent lamp operated at frequencies of 1-15 MHz

摘要

A RF electrodeless ferrite-free fluorescent lamp with a re-entry cavity was studied at driving frequencies, f = 1.2-15.0 MHz and RF power up to 80 W. Induction coils with different numbers of turns, from 6 to 26, were used to ignite and maintain the inductively coupled RF discharge in the lamp bulb. The lamp ignition and operational parameters (such as coil starting and maintaining voltages and currents, lamp impedance and resistance, starting power and coil power losses) were directly measured. The transformer model of an RF inductive discharge was applied to calculate the discharge parameters: plasma resistance and current, plasma effective RF electric field and plasma e-factor. The results of the calculations are in good agreement with the experimental data published elsewhere. Due to low power losses in the induction coil with large number of turns (26), the power efficiency of the lamp at the frequency of similar or equal to 2.65 MHz was high, 92%, which provided high lamp efficacy of 83 lumen per watt (LPW) at a RF power of 60 W. [References: 14]