Re: MH Ballast why?

Don't confuse metal halide lamp with tungsten halogen lamp.
A metal halide bulb has no filament of any kind. It's a discharge lamp,
like mercury lamp or fluorescent tube.  A ballast is needed to limit
the current. Besides, an ignitor is needed to start the discharge.
Shing LAM  L	    shlam at plato_eee.hku.hk