Is there a reason you do not want to plug the car charger into the cigarette lighter?
that would be the cheapest option.
only reason not to, that i can think about, is if the cigarette lighter port does not turn off at all.
I'm trying to keep costs as low as possible for a carPC, so I'm gonna go with a Galaxy Tab 2 7" (unless there are better options). My question is, can I splice up a car charger to the 12v constant line on the factory radio harness, and use a relay on the switched line to turn it on and off with the ignition? This seems likes the cheapest, and nicest way to power the tablet.
Plus, I'm not sure how many amps the cigarette outlet puts out, I also have an AC inverter that plugs into the cigarette outlet, so I don't want to waste some off those precious watts on the tablet, and end up blowing a fuse on the line, if I can power it from the harness.
for a permanent install, i would heavily recommend running a new power wire from the battery. it is perfectly fine to use the acc wire to trigger relays and amp turn-ons, but i don't like relying on factory wiring any more then i need to. there are a ton of variables to using the factor wiring for stuff like this. you might save a few pennies now, but it could cost hundreds of dollars later if you happen to damage the wire or the car adding a load that the car's wiring wasn't designed to handle.
for instance, in my car, there is a 10A fuse for all the accessories in the car(i know of this fuse because i've blown it more then once 'troubleshooting')-- so by the time you factor in the draw of all the other components, what started as a 10A fuse now only looks to have 2-3A available at the very most, which is usually not enough overhead for certain devices..
i have used walmart wiring kits in the past-- most are under $20, and they do the job fine.
My OLD 2001 Mitsubishi Eclipse GT:
"The Project That Never Ended, until it did"
next project? subaru brz
I figure it can't draw more power than a factory/aftermarket head unit would, and I won't be having a head unit. So load on the circuit shouldn't be an issue right? a 5v 2A charger is drawing 10w...a head unit operates at 12v so it would need to draw 833ma to draw the same amount of current. I guarantee you it draws more than that.
If that radio circuit is capable of the Amps required, fine. (Old constants were low current "memory only". These days it seems the ACC or IGN +12V are sensing only with the "constant" supplying the main power - ie, 10A fuses/circuits or higher.
I assume you have a switch or circuit to turn it off?
My plan was a relay on the ACC line, so it was only on when the car was on.
EDIT: Free from mod verification on my posts. Feels good...