Discrete SMD 7-seg display out of 7 LEDs? - Page 1
Forum section: electronics / projects

author: Smokey
author_rank: Super Contributor
timestamp: January 16, 2014, 08:05:15 pm
content: Anyone ever made a tiny 7 segment display out of 7 SMD LEDs? I've seen bigger discrete displays using a few LEDs for each segment, but I need it to be really small. The smallest 7-seg package I found is still too big (0.275 x 0.5in), and about 50% bigger than 7 0603 LEDs in the pattern right on the PCB.I'm curious if it will end up TOO small and I won't be able to tell the individual LEDs are supposed to be segments.Thoughts?

author: miceuz
author_rank: Frequent Contributor
timestamp: January 16, 2014, 10:38:06 pm
content: take 7 0805 resistors and arrange them on your table. have a look and decidethen you can try with 0603if you don't have any 0805 resistors, desolder some from that ancient modem you have laying around.

author: dreaquil
author_rank: Regular Contributor
timestamp: January 16, 2014, 10:52:37 pm
content: http://farm9.staticflickr.com/8477/8226009723_cb1bcef75f_b.jpgI found this pic on the net .. not sure if it helps

author: Rudane
author_rank: Regular Contributor
timestamp: January 16, 2014, 10:57:28 pm
content: Seen this previous post?https://www.eevblog.com/forum/buysellwanted/wanted-*very-small*-displays-7-segment-and-alphanumeric/

author: Smokey
author_rank: Super Contributor
timestamp: January 17, 2014, 04:55:33 am
content: Thanks for the replies.....I had already placed the LEDs on the layout, so I have a good idea of what it will look like physically, I just have no idea how it will look when the LEDs are lit up. What I'm afraid of is that the LEDs are going to look too much like point sources and not little rectangles so the whole display will look like a little ball of light and not individual segments.Any source of a component has to be readily available through a major distributor, so old stock or crazy alibaba parts are outI think I may just give up on the 7 LED discrete display idea. It's looking less and less plausible the more I work on it.

author: calexanian
author_rank: Super Contributor
timestamp: January 17, 2014, 05:39:03 am
content: If you only needed a few you could hack old calculators with the tiny little displays.. bubble LED's i think they are called.

author: pickle9000
author_rank: Super Contributor
timestamp: January 17, 2014, 05:48:11 am
content: Use a double sided board , drill or mill slits/holes for the segments. Keep the foil intact on the viewing side, that keeps the board glow down and you can still make out the segments. You can always mount a magnifier to enlarge.

author: Smokey
author_rank: Super Contributor
timestamp: January 17, 2014, 05:58:38 am
content: Quote from: pickle9000 on January 17, 2014, 05:48:11 amThis is going to be a production board so no hand hacking allowed. 4 layers with 2oz copper. I had the thought of using those bottom mount LEDs that shine though a route, but all the routes will eat up too much board space on all layers.The lenses or magnifier idea is interesting though. Anyone know of any production parts that are just the 7-segment window without the LEDs in them? That could be made really small and cheap in theory.