Instructables
Picture of Custom LED Sign
Ever wanted to make an led sign for one of your projects? Now you can! In this instructable I will show you how to make your very own led sign. I will cover everything from designing your sign on a computer to calculating led values.This was my first soldering project and it turned out great! Make sure to read this whole instructable before you start.
 
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Step 1: Materials

Picture of Materials
What you will need:
perf board without pads
leds*
solder
soldering iron
windows excel
2 colors of sharpie
DC power supply

optional:
multimeter
tape
paint
dremel or saw

*I recomend you buy diffuzed leds and not high brightness leds. I bought high brightness leds and you are blinded by this sign. When almost 100 leds are shining directly in your face it is like looking into the sun.

Step 2: Design your Sign

Picture of Design your Sign
Now that you have everything you need you can start designing your sign! You will be using excel to design your sign. You fill a cell where an led will be placed. To begin, open excel and make the all the cells squares. Then click on a cell and, using the fill tool, fill the cells to make letters. This may take a few trys to get good looking letters. Remember, this is just a rough draft, you can make it look better when you place the led on the clad board.
i need to know to 100 leds to connect the world "DIGITALK" how many power supply should i give

Your question is a little unclear, but I will try to answer as best as I can. For simplicity sake, connect the LED's in parallel, and then run on a 3V source, perhaps a voltage regulator or 9V source with a voltage divider (Google a schematic or video). Then assuming your LED's run on 20mA (standard as far as I'm concerned), find the amperage needed.

0.02 (amperage) * 100 (number of LED's) = 2 amps

So if your going to run this of off a battery, get a long lasting high mAh (milliamp hour) battery, preferably a rechargeable one like NiMh. Another option is to run it off of a wall adapter, and if your lucky you will find one that supplies 2 amps or greater of your voltage choice. I would stick with rechargeable batteries, because you can get around 2.4 mAh in each 1.2V cell. So as far as I know your sign should last for around an hour or two when left on continuosly.

Hope this helps! - Sam

Huma_Rana1 year ago
Can't i connect the positives of all led's together and all negatives together and then connect to the +ve and -ve end of the supply?
Thanks for the tip, I have never used perfboard. My experience with soldering and electronics amounts to 2 altoids flashlights and a star constellation, a beginner for sure. I am planning on making signs for my nieces and nephews. Do you have a good resource for low cost perfobard, online I suppose? I looked for some at Frys but they were quite expensive, since I am making 4 of these I'm trying to keep the cost down.

Also, did you use 3mm or 5mm LEDs? You said you recommend diffused LEDs, would you say the same if you were to change the color of the sign to say, green or blue? I appreciate the reply!
sscsnake (author)  envirolutionary2 years ago
I am not sure where to get perfboard for cheap. I bought mine at radioshack. I used 5mm leds I got on ebay for very cheap(~$6 for 1000). I would still recommend diffuzed leds because when you at the sign straight on it is blinding and when you look at it from angle you can barely tell that it is on.
Thanks a lot for you help on this, one last question. I have been trolling ebay and trying to find perfboard similar to yours which I have found. What I have not been able to find is the metal that goes over the perfboard. How did you make the nice cover for it? Also how did you mount the sign? I was thinking of using a project box but I don't know how I could get a cover with predrilled holes such as yours. I ordered my LEDs, mostly diffused but I couldn't find blue/purple in diffused so I settled for low mcd. Would you be able to advise me on the wiring?
My first sign will have these types of LEDs: Size: 5 mm Lens Color: Water clear Emitted Color: Ultra Violet Viewing Angle : Approximately 25 degree Forward Voltage: 3.0 V- 3.2 V Forward Current: 20mA Wave Length (WL):395-400NM Luminous Intensity: 300 mcd-500 mcd Lead Soldering Temperature : 260°C (<5Sec)

the second:
http://i.ebayimg.com/t/100-pcs-QLMP3508-HEWLET-PACKARD-GREEN-DIFFUSED-5mm-LEDS-/00/s/NDgwWDY0MA==/$T2eC16VHJF0E9nmFRpOQBQge!bL3B!~~60_12.JPG

I bought a number of resistors as well. 

sscsnake (author)  envirolutionary2 years ago
I didn't make a cover for it, I just colored the perfboard with a big marker. I'd recommend spray painting it instead because the marker looked streaky. I mounted the sign by hot glueing it to knex pieces. I was going to mount it on one of my knex models but sadly I had to take it down before I had a chance to mount it and film the result.
This is great! I have a question though, I'm new to the DIY electronics world and I was wondering why you wouldn't want to have perfboard with out the copper pads? It just seems like it would be harder without, and harder to find the perfboards. Just wanted to get a reference, for when to (or not to) use the pads. As well as a good place to buy perfboards (on the cheap...) Thanks!
sscsnake (author)  envirolutionary2 years ago
The main reason I didn't use perfboard with the pads is because it is not needed. The leds have lond enough leads that I can simplely bend them over. This saves solder not having to connect all the pads and makes coloring the other side easy (Black Sharpie looks dull on the board and shiny on the pads). Perfboards with the pads are mainly designed for IC's and more advanced circuits. This project is simply lots of leds soldered is series. There is a big differance in price too. It costed me about $2 for the perfboard in this project, and I have some left over. The perfboard with pads costs $4+ for an amount that I used in this project. I hope this helps and feel free to ask any other questions you have.
correction: why you would** want to make this with a perfboard without pads.
rloudermilk2 years ago
I really like the excel idea for mapping the layout. I did something similar to this for my college graduation cap. I used plastic compatible spray paint to paint the board black and used clear LEDs (12,000 millicandellas). Instead of excel I used adobe illustrator and just made 5mm circles to copy and paste throughout my design. Soldering was time consuming but wire wrapping is a great alternative.

Dremel is the greatest tool invented since duct-tape.
MTtoo2 years ago
This is a well written instructable with great pictures. I have wanted to make led tail-lights for my aging pickup. Older bulb style tail lights are not as bright as the newer models with led tail lights. I am thinking about safety. Your article is so well written that determining the voltage and amperage is no longer a mystery.
I think it will be possible to get the 12 volts at the tail light connection, leaving the bulb intact and operational. Since the leds will be a lot brighter, they will outshine the original bulb and be more visible.
Care to write an instructable about upgrading tail lights?? It will be greatly appreciated.
I will vote for you!!
sscsnake (author)  MTtoo2 years ago
It should be the same process. Just make a sign in the shape of your tail light. I would remove the original bulb, though. The enemy of LEDs is heat, and the original incadecant produces alot.