Bill Shymanski wrote:
"Arfa Daily" wrote in message
...

"rebel" wrote in message
. ..

On Wed, 14 Feb 2007 02:22:46 -0800, John E.

wrote:

Came across a 90's vintage IR controller for printing industry

(drives Q-H

lamps for drying ink in the paper path) that uses a single-digit

7-segment

display that looks like a nixie tube (more like a white-hot wire

segment)

display. The 16-pin DIP socket is marked IEE-Atlas, and the

single-digit

display is marked "IEEFFD21 5DX C". Each digit display is 15 pin on

a 16

DIP
pattern.

I've done the requisite Google, but come up with nothing. The

drivers on

the
PCB are MC14511BPC which is a standard CC LED 7-segment driver.

What are these? They don't look anything like LED segments (I can

see each

wire-like segment behind the glass front of each digit's display).

Can I

just
replace these with a common LED display? Or are replacements

available?

Once upon a time there were incandescent 7-seg annunciator devices,

under

various names. Minitron and RCA's Numitron are two names, but do a

google

search on "incandescent" and "7-segment" for heaps of background.

When I was young and enthusiastic, I built a frequency counter that

used

these. I think it was a Practical Wireless design. It's still around
somewhere ...

Arfa


Ahh, yes, -when I was about 14 years old I built a digital clock out of
TTL devices from a Popular Electronics plan, which would have featured
Numitrons as the display elements. I made what must have been the
ugliest printed circuit board ever - my school class used the Mactac and
hobby knife approach for making PCBs, which gave incredibly crude
results. Sadly, my troubleshooting skills were not up to overcoming my
crude construction technique and I never got the darn thing to work - it
wasn't until years later I found out the key difference between the 7447
display driver and the 7448 that the fellow at the electronics
wholesaler sold me.

I may still have the Numitrons sitting in the basement somewhere..

Bill





Perhaps you should try to get the thing working now that you're armed
with more knowledge? If you find the Numitrons and would like to get rid
of them I'd happily give you something for a set. I build clocks using
odd old display devices.