Nixie stuff (Was: Re: A Proposal (was...))

From: Allison J Parent <allisonp_at_world.std.com>
Date: Thu Oct 29 07:36:23 1998

< > > Don't they run on 170 volts or somesuch wild figure???
< >
< > A nixie tube is basically a neon bulb. It turns out that if you drive
< > neon bulb from DC, then the cathode appears to glow, and the anode
< > doesn't. A nixie tube has a number of cathodes in the shape of the
< > required symbols (often, but not always, 0-9), and a mesh anode.
<
< Wow. I didn't know that. I thought you had to supply the Nixie with AC

160-250V DC, thought he dc does nto have to be wel filtered or regulate

< I'll have to rig up some kind of ladder network, I guess. I have a boar

A transformer with a 120v secondary and a voltage doubler will do. The
current is very low, nominal series resistor is something like 47k.

< out of an ancient calculator with 9 or 10 Nixie tubes (and a neon bulb
< for the '-' sign). I've always wanted to fire it up, but never had the
< time to build some kind of high-voltage BCD driver. This sounds like a

That's where the work is. Back when those were used inexpensive HV
transistors with a 100v breakdown were hard to find and ICs good for
more tha 30V were scarce. So there were some creative tricks used
depending on the specific tube used.

< for a PIC, a kind of serial to Nixie driver. I could always drive it wi
< an ancient UART (the kind that didn't need a CPU) and a pile ot TTL, bu
< I think the PIC could keep the part count low.

Uart and a small pile of ttl really. The bulk of the hardware will be
the drivers unless you can use the 74141.

Allison
Received on Thu Oct 29 1998 - 07:36:23 GMT