In message , Andy Hall
writes
On 18 Feb 2004 22:51:33 GMT, "Bob Eager" wrote:

On Wed, 18 Feb 2004 20:00:35 UTC, wrote:

no potential across the neon, so it goes out. A downside of this Ingeneous
scheme is that if the bulb blows, the indicator no longer lights; and it's
shot to pot if you use compact-flourescent or similar.

Funnily enough, we have one circuit with two compact fluorescents on it
(nearly the same, apart from the white powder! :-)). It has one of
these neon visibility things on the switch and it still seems to work OK
(there are no incandescents in the circuit).

Don't know WHY, mind....!


A large R across the fluorexcrescent?

That would be enough to light the neon.

I have a neon visibility thing on a circuit connected to a HF
ballasted fitting with emergency maintained capability.
Must be an R there as well


.andy

Any electronic HF ballast device is likely to have an X capacitor (i.e.,
live to neutral) at the input for EMC filtering. That will give enough
current flow to light a neon up-stream.

--
Steve