You guys have convinced me to try some LED projects, I just have one quick question.

I know from Pringle's LED Quick Guide that I can only get about 5 LEDs in a series before I out of volts. However, is there a limit to how many I can hook up in parallel? And do I have to use a completely different power source with each group of LEDs?

I tried to search for the answer but LED as a keyword bring up too many results to display. And some one should write up a good LED DIY. The Quick Guide is a good start but some of us need pictures and examples.

 

You can run as many as you like in parallel (each led needs a resistor though). You can also do parallel/series combinations. You do not need to run a whole new line if you run them in series as long as you branch off before the resistor, it will work fine.

The only thing to watch is how many watts (or amps) you are drawing off a single line. For example, a 20 guage wire can not take as many amps as a 12 guage wire. Sorry, I dont have exact amp ratings off the top of my head, but I am sure a search on google will yield some results.

 

Thanks Casper, I'll give it a try. Oh yeah, does anybody know a good place online to buy LEDs? The local electrics store doesn't have much for color selection.

 

look on e-bay for Chi Wing Industrial Trading (HK) Ltd. or you can e-mail him direct at cwithk at netvigator dot com

Here are some prices he gave me last time I ordered.

> 100 Bright white leds 5mm 5k mcd USD17.00
> 100 Bright red leds 5mm 5k mcd USD10.00
> 100 Bright blue leds 3mm 5k mcd USD8.00
> 500 Bright blue leds 5mm 5k mcd USD40.00

 

thats my guy too. great stuff.

you wont have to worry about burning up wires untill you start hooking up thousands of leds, literally.

heres a good read for you...http://electronics.howstuffworks.com/led.htm

be sure to click on links spread throughout the article. they'll teach you other things about electronics that are definately helpful.

specifically, this one...http://science.howstuffworks.com/question501.htm

 

Need I remind you of my instrument cluster? tongue.gif solder splash can do bad bad things lol. Yea, he's right, if you take your time and inspect your work first, its all good. If I calculated it right, 100 led's is about 0.2-0.6 amps (normal-max)

 

well, here is an example. each led uses 20 mA. thats .02 amps. multiply that by the voltage in a car(12) thats .24 watts. a typical dash bulb is prolly about 10 watts. so you could use 40 leds and still use less power than one incandescent dash bulb.

 

^^ Exactly the reason I'm getting into LEDs. Cheap in both cash and power.

Here's my plan. I'm going to add a led to the door handles and possibly replace some of the stock interior lights. What I'm asking the questions for is my attempt at under-dash lighting. I figure 3 or 4 bright LEDs will light up as good/better than a neon tube and use a lot less power. Or at least I'm hoping so. If you guys have any advice, please enlighten me.

 

well, neon tubes dont really use to much power either. im pretty sure leds are still more efficient though. have you thought about led tubes?

 

Yeah, but they're generally more expensive than neon. In a month or so I can afford to try some LED experiments. If I can't get the look I'm going for in the interior then I'll probably either stick with neon or use some LED tubes. Time will tell.