9-digit LED for $0.99??

[dinofx]

Is this really a 9-digit LED, or is it simply 9 round LEDs? And more importantly, where are the specs on how to use it?

**broken link removed**

 

[JimB]

Yes it looks like a 9 digit seven segment LED.
As far as the specs for it go, I guess this thing is well obsolete, I did a Google search for the part number (A1198A was it??) and found not very much.

At a quick guess it will be like some old HP displays I have in my junk box.
The seven segments of each of the digits are all connected together, and each segment has its own anode or cathode, and you have to drive them using a multiplexed technique, otherwise there would be 63 connections to that thing (9 digits times seven segments).

JimB

 

[DirtyLude]

I think it's pretty clear from the picture that it's just 9 LED's. This looks like a scrap part. Do you really need specs? There's 18 contacts and 9 LED's it would be pretty simple to find out what contacts go with what LED's.

EDIT: Beat by a minute. Yet, still trying to figure out how 9 LED's in a row on a board can be a 7 segment LED. The picture looks pretty clear to me to be just 9 LED's in a row.

Hopefully the image shows:
**broken link removed**

 

[dinofx]

I think it's pretty clear from the picture that it's just 9 LED's. Do you really need specs?

Well no, not if it's just LEDs. Still, not a bad price, but perhaps tricky to mount anywhere.

Perhaps they are referring to digits in the binary sense

 

[DirtyLude]

I would say it's an iffy good deal. It depends on the LED's used and whether you're actually going to use the product as is. When I first got started I got a bunch of scrap parts like this from electronics goldmine and other places that sell surplus and I would have to say I didnt get a very good deal.

You can get 5mm LED's for 10cents each at Mouser.com. With a bit of perfboard you can make up the same thing, or very similar for nearly the same price, only with the actual number and colour of LED's you want.

 

[Mike - K8LH]

Anybody remember Poly-Paks (I'm probably dating myself)?

Mike

 

[zevon8]

Looks like an old calculator display. Nine 7 segment digits, plus decimal, and 9 commons. Matrix, just like stated above. Looks like what was in my old TI-88 from like 1983.

Okay, so I just dated myself too. LOL

 

[jbeng]

Definitely not just a row of discrete LED's. It's a multiplexed, monolithic LED display with "bubble" magnifiers. Like zevon8 says, it looks like a calculator display - old school. Similar to HP-5082-7200/7400 series displays. The digits will probably be about 0.2 inch tall when viewed. For a dollar each, I'd probably buy a couple just to play around with 'em. If you're a PIC (or AVR) man, I'm sure it wouldn't be too tough to program one to use as a driver. Discrete IC circuitry, however, will be quite messy.

And, I remember Poly-paks, too (from the back of Popular Electronics).
JB

 

[Papabravo]

I got my first batch of TTL DIPs from Poly Paks.

 

[DirtyLude]

I stand corrected then. If there's actually digits displayed, even that small, it sounds useful.

 

[Someone Electro]

Its ment to prject it.

You need to put some semitransparent plastic over it and it will project the numbers on the the plastic so there biger.

This is a very old kind of display.

 

[RODALCO]

Exactly as said before, this is from the older type calculators which had miniature LED displays, similar as the first digital watches in the mid 70's.
Sometimes a red filter and curved display enlarger was used.
The actual digits are quite small, probably the same size as a 5mmØ LED but then 7 segment.

So this is a 9 digit, 7 segment display.
Cifre (French) means number or digit.

 

[agent420]

Yup, those are old school numeric displays. Was the only type of numeric led display for a long time in the 70's. Actually almost hard to find these days.

http://www.datamath.org/Display/Display.htm

 

[audioguru]

Those 30 years old displays were very dim. Modern LEDs are much brighter.

 

[agent420]

I don't recall them being that dim. Easily readable in a lit room. Maybe the red filter often used cut down some brightness.

Actually I think they look kind of cool because they're almost like miniature Numitron's; you can see the diode elements through the clear magnifer bubble (unlike most diffused devices today), producing an 'illuminated wire' type of appearance. But they are small.

[edit]

Given the era of manufacture, I wouldn't be surprised if the connection contacts are gold plated.

 

[William At MyBlueRoom]

Anybody remember Poly-Paks (I'm probably dating myself)?

Mike

Err yep. Popular Electronics used to advertise them (or am I losing my memory?)