USING PSPICE TO DETERMINE LAMP CURRENT VARIATION DUE TO ELECTRONIC BALLAST COMPONENT TOLERANCES

This paper studies the relationship between component tolerance and 1) total tamp current variation and 2) lamp current imbalance between la mps on one ballast, PSpice simulator and a four-lamp fluorescent curre nt-fed push pull inverter is used in the study, The concept of compone nt quality level (CQL) is introduced, Components with different qualit y level and tolerance are selected and a normal distribution is assume d, The studies indicate that to meet lamp current tolerance specificat ions and to produce lowest cost products, it is not enough to just tig hten the component tolerances. Both CQL and tolerance have to be consi dered.