Building a car adapter?

[Kc2iLq]

I just bought a 20Gb 3g iPod and want to use it in my car. However, I'm not about to shell out $25+ for a cigarette lighter adapter. I called up Mouser Electronics and ordered a firewire jack and a 7812 figuring that I can build my own. I already have the dock cable as well as a cigarette lighter plug to use.
My question:
Does anybody forsee any problems with this project? The parts from Mouser only cost ~5 bucks shipped, so it's no biggy if it doesn't work out.
TIA!

-Kc2iLq

[jerrodh]

This guy did something similar, but with batteries. Try adapting this to the 12V DC Cigarette Lighter.

http://www.drewperry.co.uk/index.php?do=iPod&ipod=battery

[Kc2iLq]

Thanks azdude. That's pretty close to what I was thinking, as for the 1394 jack anyway. I'll get a schematic drawn up eventually, but I was thinking of using a 7812 to regulate the voltage and some capacitors as well as a varistor to keep it stable.

-Kc2iLq

[Kc2iLq]

How finicky is the iPod when it comes to voltage fluctuation? I just realized that the voltage can drop below 12v when the lights and stuff are on so the 7812 would shut off. If I was to just throw a couple 2200 or 4700?F caps in, I could reduce any ripple and keep it from dropping out if I turn everything on at once. So, if the output voltage varies from like 10v to 13.8v, will the iPod not like it (will it break)? It should take from 8-30v, but I'd assume that it needs a constant voltage.
Somebody must know...

-Kc2iLq

[coons10]

That thing is pretty cool!

Good luck getting it through airport security though. I know if I was working screening station, that contraption would certainly catch my eye.

[Kc2iLq]

I got the parts from Mouser today. I'll probably use a pre-etched circuit board to save time and agrivation. I found out that the 7812 will pass through any voltage below 12v so I can still use my original design. I'll post some pics when it's all done.

-Kc2iLq