ABSTRACT
The ferrite core used in induction-coupled fluorescent lamps, such as those described by Anderson [1, 2], must have sufficient Bs,, to maintain the discharge under all conditions. Since Bs„, is a function of ferrite temperature and decreases with increasing temperature, this determination must be made when the lamp is fully warmed up. If the ferrite is mounted outside the evacuated lamp envelope, as in the Philips QL, GE Genura® or Osram Sylvania Icetron/Endura lamps, it is relatively easy to measure the peak ferrite temperature while the lamp is operating and then determine Bsa] for the ferrite using Bsat vs. temperature data for that particular ferrite core that was measured before the lamp was constructed.
