[sdiy] the function of neon lamps?

[Paul Perry]

The key to the neon lamp (as a circuit component) is that it
conducts only when a certain voltage is reached across it (say 100V) and
then stays conducting till the voltage has fallen (say to 70V)
So if you put a cap across one, and connect a resistor to a voltagee greater
than 100V,
the cap voltage increases until it gets to 100v, then it suddenly discharges
to 70V
and the cycle repeats, whihc gives you a sawtooth.
You can make oscillators & simple logic using these.
Another place you used to see neon tubes was as voltage regulators,
you can wire them up to give a steady discharge, at a repeatable voltage.
Kind of like a zener.
The military versions used to have quite a bit of radioactive material in
them
to make sure the neon would ionize.
0A2 was a common one, the '0' stands for the heater voltage ( there wasn't a
heater.. geddit??)

paul perry Melbourne Australia