Working of Compact Fluorescent lamps

The ultra violet light produced by exited mecury atoms ( which in turn produced by collision of electron from cathod)  is converted to visible light by phosphor. 

Working of cfls

Requirement of Ballast

  • Required to regulate current so lamp operates at correct voltage.
  • Provides necessary voltage to start and sustain the arc.
  • Without a ballast, CFL lamps would draw too much current and burn out straight away.
  • Can either be remote (part of the fixture) or built  into the lamp (integral).
  • Electromagnetic - heavy, large and less efficient.
  • Electronic - small, light, efficient and flicker-free