Best Bang For The Buck Challenge

[SETEC_Astronomy]

I have wanted to make an LED sign for some time now, the type that scrolls messages and does simple graphics. But every time I start pricing things out the LEDs throw me way over budget. I always look for the cheapest LEDs around but by the time you get enough to make a decent sized sign the cost of the LEDs alone is over $100. Because of this I challenge you all to search your favorite suppliers for the best LEDs for the money. The basic criteria are Color, Brightness, Cost and Size. For single LEDs the ideal size and package would T1 3/4. LEDs already in a matrix would have the cost per LED figured by dividing the total unit cost by the number of LEDs in the matrix. The matrix LEDs should be pretty decent size couple inches by a couple inches. Each color would be judged differently because blue and white carry a premium. Cost is important and so is being matrixed. Matrixed LEDs while maybe more expensive may save in the long run because the reduced cost of implementation. Brightness comes in last. Most LEDs today are plenty bright for either a shaded sign or any other type. Go see what you can dig up. Thanks.

[Will]

You c an buy a functional scrolling display in Sams for about $180 - you should look at one !

[HighFrequency]

yeah but I think the point is that he wants to build one.

[SETEC_Astronomy]

Yes my intention is to build not buy. And the $180 price is still about $100 more than I want to spend. I have everything ready to as far as control circuitry goes, I just need the LEDs. I have to say I'm quite surprised, I thought everyone would chime in with their favorite place to get LEDs/parts and what price they have. Maybe if I mentioned capacitors and time or LEDs and running ten amps through them I could at least get some more posts. My thought was everyone shops at different places and would know more places to check then I would. I have checked the obvious (jameco, mouser, digikey, alliedelec, sunled, sparkfun) but know there are tons of other great places that I don't know about. Oh well I guess I'm still on my own.

[Bob Scott]

If you are going to connect these LEDs to a matrix, you must be strobing them line by line or column by column.

I have seen mechanically rotating LED signs that simply use a single column of LEDs and that single column simulates the entire plane simply by its fast rotation, switching column by column information as it moves from left to right.

I content that this method would be your biggest bang for the LED buck. They have been selling prebuilt displays like this for years.

Regards,
Bob

[bigkim100]

A electronics place in toronto offers huge pieces of what were once gigantic led matrix displays. I think that a 12x24 inch slab costs around 10.00. Lord only knows how many leds are on each slab.
They also have complete brand new signs that are around 6 inches high, by 4 feet long. These are brand new, commercial units, that look great, are fully complete, but do not have a programmer, so you would have to figure out how to program them yourself. I think they run around $50.00. They have no documentation on these units, but they power up, and go through a visual test sequence on the display.
Let me know if you are interested.

[SETEC_Astronomy]

bigkim100 those don't sound like exactly what I wanted but they seem like a good deal and I could probably make use of them or the parts. Could you PM me with the info I need to look into them deeper or perhaps buy. Thanks.

[Bob Scott]

Hey, PM if you want, but post the information here too please. Which electronics source? Do they have a website?

Bob

[bigkim100]

Yup, the place is called A1 Electronics in Toronto...and yes they do have a website. The signs, and pieces of larger signs, are not in their catalogue, but a email to them will get a quick response, with a picture, if you request it. They are actually a nice bunch of guys.

http://www.a1parts.com/

[Bob Scott]

http://www.demoboard.com/anchor.htm

This is a link to another hole-in-the-wall electronics shop called ANCHOR where I shopped often when I worked in San Jose. They stock all kinds of stuff including 1% resistors, SMT, etc. BAGS of 100 LEDs. (All the same part #, not like a RS grab bag.) They do mail order in the USA. I don't know if they ship to Canada. The link to their 16 page catalog is:

http://www.demoboard.com/Anchor_pricelist_Dec05.pdf

Another good source for hard to find semiconductors is:

http://www.acecomponents.com

Their stock list is downloadable, several megs is BIG. They buy surplus by the trainload.

Regards,
Bob