Interesting LED displays.

[Duo]

I have found these LED displays in a pile of ham radio junk that I recieved from a friend.

They are the same style of display used in my HP45 calculator and I wish to use them to make a display for my atomic clock project which is here in another thread.

Does anybody have any information on these devices? Like what the pinout is, or any good chips for driving them???

[Duo]

Darn, I forgot the picture!

[Duo]

Anybody?

[Lisandro_P]

I have a set much like those, also from an old calculator. Lovely, aren't they? They give the best eerie red glow ever, but are kinda small.

Anyway, they're common LEDs; don't know exactly what type though. The arrangement is exactly the same used today for more modern display: common anode/cathode for each segments in all digits, and separate catode/anode to select it individually. Meaning that, yes, they need a controller. Maxim made a nice one (MAX7219) that can drive up to 8 digits via a serial line. They can be chained to drive more digits too.

My leds light fine with about 5-6mA of current BTW.

[Duo]

Thankyou. I'll give that one a try.

[JOE DIRT®]

I built a 6Mhz frequency counter with one of those displays about 15 years ago....still works good


DIRT®

[Duo]

Interesting... Do you still have any info on the circuit or parts?

[fdegrove]

Hi,

If you think LEDs look cool take a look at this fellow's site:

DEKATRONS, NIXIES ETC...

Cheers,

[JOE DIRT®]

DUO....I`ll open up that baby and see what the hell I did...maybe show some pics also

[Duo]

Joe Dirt: Thankyou very much, that would be great to see your project.

fdegrove: That's I very good site to see nixies and other interesting display devices. I was actually just looking at that this morning

I have some nixie tubes and I soon intend to make a clock out of them. That will probably become part of the clock project I'm doing with the LED displays.