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[leijae]

the only thing i dont know is the size of my resistor.

I will be using 5mm ultra bright LEDs

clear rubber hose

i will have a 2 2ft rods with about 20 LEDs

also i'll have 2 1ft rods with about 12 LEDs

anyone know? the resistor size?

[Rylinkus]

QUOTE

Section B - Where to get modding supplies. (thanks a lot to cleary for his links)


B01. LEDs
- http://www.LSDiodes.com - Highly reccomended by a lot of modders on the scene. LEDs & Resistors.
- http://www.besthongkong.com/ - Also highly reccomended. LEDs and resistors.
- http://www.coolerguys.com/ - Expensive, but one of the few places that has RED/BLUE bicolor LEDs. subdigital had some advice to offer - he phoned coolerguys, and they suggested that people phone in their LED orders to save money on shipping - around 5 bucks! See their contact page for phone numbers and ordering hours!
- eBay LED listings - You can get bulk LEDs for very cheap on eBay, you just have to watch what's there.
- Don't buy LEDs at Radio Shack. They are weak and terrible.

QUOTE

D03. What type of resistors do I need for ____ LEDs?
- A collection of posts and links about calculating resistance: http://forums.xbox-s...showtopic=61484
Calculator: http://www.bit-tech.net/article/68/
Picture for equations (thanks TykSak_):
http://www.indexside....dk/OhmsLaw.png

If you have any other questions feel free to hit me up. Im an electrical engineer so should be able to help you figure out LEDs.

[kevinlekiller]

Fyi , a car's voltage is variable. In other words it is NOT 12v. When you start the car the voltage will drop VERY low. And once its started the power comes from the alternator , a new alternator puts out about 14.4 volts. As they get older, they put out less. And when the car is off , it depends on your battery. If its new , between 12-13 volts , old could be alot less.

All this to say : you cant just wire LED's on the electrical system of a car. You need to make that voltage cleaner (the cars electrical system has spikes since its not filtered) by regulating it.

You can get voltage regulators at radio shack , they take 3-30 volts and put out 12v.

But you still need to clean the input voltage a little from spikes, add a small cap between the positive and negative terminals on the regulator.

A regulator can handle about 1a max (the radio shack ones) at 1A you need to heatsink them , since your using a car, bolt them to the metal of the car.

[zerocover]

You dont need to worry about voltage regulation in regards to leds. They are extremly resiliant, and can usually take largley variable voltages. Mine have been running for over a year just be sure to be giving the leds less then what they should have optimaly. IE one led takes 2 volts if you use 8 of them in series then you're optimal voltage is 16 and your max is much heigher still.

Ive run single leds off only 1 volt or off all the way to 9 and they worked fine, although really bright at the upper limits (instantly fried them at 12 though, wonder how carinogenic the burning led smell was). The more voltage you throw at them the less there life, so if you run less voltage they'll last longer. At optimal they should last some 10 years so thats a good place to start.

You do need to be aware that youll need either one really beefy resistor or a small one for each stick. Its cheaper the latter way. I used 1/2 watt resistors for each stick of 8 (radioshack) I tired with my 1/4 watters but they heated up an amazimg amount, they were really hot to the touch, even though they should have been within spec.

Since we drive proteges we really dont have to worry about voltage drops or spikes. Our electrical system has huge capacitors built into it so the voltage is always 13.8 volts, no matter what the rpm (when the car is turned on). The voltage does drop while cranking but I hardley even seen the lights dim, so the drop isn't significant.

[leijae]

i've been giving it some thought, zerocover and i have the same vehicle and i respect his knowledge of the vehicle(due to posts on different forums). So i've decided to give up on the project and just buy the underglow from ebay. thanks for all the info though guys.