Ballast method and apparatus and coupling therefor

摘要

A ballast is disclosed which can operate at an effective level of output with a number of different input voltage levels. A ballast is also disclosed that uses a ceramic (148) as a heat sink for switching transistors (144, 86, 96). A ballast is further disclosed which uses a start signal (48) for a power factor circuit (40) to boost voltage after the load for the ballast already has a current applied to it. Furthermore, a ballast is disclosed which has a transformer (100) having a permeability which varies somewhat inversely with temperature over a given temperature range.