Neon indicator lamp glowing with only one connection?

[Rock]

I tried to find some info on this on line but failed.

I've got a high voltage power supply, that has a neon bulb indicatior
on it that has only one connection to the circuit board (both leads
connected together). It is on about 2 inches of wire seperated at the
bulb, but with both wires in the same hole on the board. This point is
connected to a pulsed high voltage source through a capacitor, prob.
around 1000vdc pk.

So, how does this work, or where can I find some info about this?

Thanks

Rocky

 

[Mark]

well inside the buld the two terminals don't touch anyway...

in your case those two terminals are tied together and are one
terminals and the chassis is the other terminal

the neon light when there is a large electric field from the terminals
to the chassis. Also you can think of it as a capacitance from the
terminals to the chassis and you have an AC (or pulsing DC waveform).

BEWARE... this means you have a very high and maybe DANGEROUS voltage
there.

Mark