25 May
2005
25 May
'05
5:02 p.m.
Eric wrote:
I've just looked at the specification for Chicago
Miniature Lamp
neon bulbs, and it looks like they don't have anything suitable.
The problem is that the specifications for the "maintain" and
"breakdown" (start) voltage ranges are too wide, and often there
is overlap.
This doesn't rule out the use of commodity neon lamps. It's always
true that V_breakdown > V_maintain. The specs are just written loosely.
I've built several neon lamp gadgets over the years (I think you saw
my 5-neon-in-a-sequence-flasher in fact) and if you start with a bunch
of bulbs from the same batch you'll end up with matching way better than
you'd expect from just the spec. Whether or not they're good enough
for a given logic circuit may drive you to hand-match etc. The same
thing is done with semiconductors, you know :-).
Tim.