computer building? was[rescue] Noise levels

[Tim H.]

No, that's caused by to cold a temp, or too low a voltage from a bad
ballast, which doesn't keep the gas in the tube lit up.  The 120hz
flicker is caused by the fact that the gas in the tube responds very
quickly to the AC voltage which excites it, which in turn causes the
phosphor in the tube to light up.  A bulb with a filament also gets the
same AC waveform (but at much lower voltage) but the filament doesn't
cool down quick enough to allow a visible flicker.  That's also why you
can see the light taper off when you turn off an incandescent light, but
it just stops when you turn off a flourescent.

TIm

On Thu, 20 Jun 2002 00:52:19 -0400
Chad Fernandez <fernande at internet1.net> wrote:

> Your not talking about the light rings in the tubes are you?  I notice
> 
> that old or cold bulbs will have traveling light rings inside the
> tubes.