ABSTRACT
Compact fluorescent lamps have, in general, higher wall load than usual linier fluorescent lamps. For example, that of 40W linier fluorescent lamps is typically about 0.04W/cm2 while that of our product is around 0.08W/cm2, which easily raises mercury vapor pressure and therefore lowers the lamp efficacy. Usually, amalgam is used to control the vapor pressure of mercury during lamp burning. The use of amalgam, however, lowers the buildup characteristic of the light output because mercury is hardly released from amalgam at low temperature. We therefore enclosed pure mercury so as to obtain enough mercury pressure at the initial stage of lamp starting. Thus it becomes quite important how to control the cold spot temperature of the lamp envelope. In this study we will show another technique to control the cold spot temperature of an electrodeless fluorescent lamp with inner coil configurations [1] and thus to increase the lamp efficacy during burning.
