5 Oct
2012
5 Oct
'12
9:58 p.m.
On 2012 Oct 5, at 8:11 PM, Dave McGuire wrote:
On 10/05/2012 10:26 PM, Josh Dersch wrote:
Like this? :) http://yahozna.dyndns.org/scratch/displays/babcock.jpg
Those digits are about 4" high, and the panels are made by Babcock
(two
panels w/4 digits each), but the numerals look a lot like the smaller
Panaplex displays I have in an old Heathkit digital clock. They
came out
of an old industrial display of some sort, I interfaced an AVR
microcontroller to the logic / power board they came attached to and
made a nice clock out of 'em...
Yes!! Very VERY nice!
To elaborate, there were several manufacturers and models of 7-
segment gas-discharge displays, they weren't all Panaplex:
- Burroughs Panaplex (original/Panaplex I)
Multiple digits per module, typically 8-13 digits for
use in calculators
Anodes are a metal grid between the viewing glass and
the segment cathodes.
Early-70s, not very common, superseded by Panaplex II.
- Burroughs Panaplex II:
Anodes are transparent conductive sputtering on the
viewing glass.
Far more prevalent than Panaplex I.
Mid-70s, quite common.
- Beckman: typically just 2 or 3 digits per envelope, used more in
instruments and the like,
such as clocks where 2-digit modules could be spaced for
the H M S.
IIRC, the Heathkit clock and so on used Beckman modules.
Mid-70s, fairly common.
- assorted Japanese types:
typically multi-digit modules for use in calculators.
Early-mid-70s, not common.
Around the late 60's, before the above multi-digit modules, there
were some single-digit tubes made. In a tube envelope just like
common nixies, but a 7-segment display instead of the nixie 1-of-10
formed numerals.
They were all subject to 'burning out', particularly the types with
the anodes sputtered on the glass, TMO the lifetimes were shorter
than nixies.
I think the last common use for them was in retail gas pumps, where
they were used from the mid-late-70s till when? - mid-90s or so? My
guess is these were Beckman types.
I've got some nice ol' gas-discharge amber
ones in the [UK] junk
box
which will get here to me one day - from what I remember of the
PCBs
that they were mounted on, they originally came from fuel pumps.
Ohhhhh,
Panaplex? Basically seven-segment neon displays? I LOVE
those. Unfortunately they tend to go for big bucks. If you have
some,
you are morally obligated to do something cool with them! Even
if it's
just yet another clock...they're beautiful displays. 