Improvement of the luminous run-up characteristics in ballas-integrated compact fluorescent lamps covered with outer globes

Ballast-integrated compact fluorescent lamps are widely used for replacing incandescent lamps as energy saving alternative light sources. In spite of their high efficacies, the luminous run-up characteristics ofthe lamps covered with outer globes are slow and rather unsatisfactory, especially within a second or two. The luminous run-up characteristic ofthese lamps should be divided into two stages: the luminous flux at starting and luminous increase for several minutes. The former is related to the mercury vapor pressure change in the discharge tube during off-period; the latter is related to the mercury diffusion along the discharge path after starting. In this paper, we focus on the mercury vapor pressure in the discharge tubes that have main and auxiliary amalgam. It is found that the mercury vapor pressure during off-period is determined not only by the auxiliary amalgam composition but also the main amalgam one and the distance ofits site from the discharge space. The luminous run-up characteristic is much more improved by using bismuth-tin main amalgam dosed in the end oflong extended thin tube connected to the discharge tube with gold-plated auxiliary amalgam flags. © 2007 The Illuminating Engineering Society of North America.