Powering a double din car radio off desktop PSU?

[EvanVanVan]

I've got a double din car radio I'd like to be able to use/test in my house so I'm trying to figure out the best way to power it. Someone on another forum suggested a desktop PSU, but for the technical electrical questions I decided to come to a forum dedicated to this kind of thing...

The DD radio is powered off of a 12Vdc source (according to the manual). The manual doesn't mention amps at all except for the fact that in the back of the radio these a 10A ATM fuse. So I'm assuming the fuse is there to protect the entirety of radio it self.

My PSU supposedly has some cables that do a max output of +12V/19A. (I included a pic of the PSU). That should be safe to run off of, correct? I realize the amps are to high but the fuse should protect the radio.

My next question, is figuring out which wires are the +12V/19A ones...According to wikipedia, http://en.wikipedia.org/wiki/Power_supply_unit_(computer), the +12 are either of the yellow ones, and the ground are black. Those should be the only 2 wires I need.

Is all that correct? I'm just looking for some verification before I fry my new $500 radio.

Thanks

Edit: and I guess a follow up to my question is, if I keep the PSU plugged into the motherboard, will I get the same +12/19A from the molex connectors? It's easy to test the 12V+, but I'm confused on how to test the amps, without actually plugging the radio in first. On the one hand I would like to make sure it's not way to much current (which the 10A ATM fuse should protect), but on the other hand, I don't want to turn the radio on without enough current and 'starve' the radio.

 

[weird_dave]

The PC PSU current is what it is capable of delivering, it won't be pushed at the radio, the radio will take what it needs (up until the 10A fuse blows, which would be a fault in the radio, not the PSU).
It'll work fine, I've used PC PSUs for similar jobs. However, to get it to power up you do need to do something to it (you may already be aware of this?)
http://pinouts.ru/Power/atxpower_pinout.shtml
you need to short pin 14 of the motherboard connector ot 0v (black wire, and yes, yellow is 12v).
The wiki page you linked to has the pinout to ATX12V2 which has pin 16 as the power-on line, whereas my link (just ATX) has pin 14, whichever version supply you have it's the green one, and you can double check by the number of pins in your connector (ATX has 20, ATX12V2 has 24).

 

[EvanVanVan]

"Power Supply On (active low). Short this pin to GND to switch power supply ON, disconnect from GND to switch OFF."

I see, thanks, yeah I wasn't aware of that. But was having a hard time grasping my head around, how to "turn the PSU on" when it wasn't connected to the computer...Thanks

And about doing it from a molex connector instead, so that the desktop pc could also be used? From your description it sounds like it should work and the molex wiki page http://en.wikipedia.org/wiki/Molex_connector seems to say I can get a max of 11A out of it...so it should work fine that way also.

 

[weird_dave]

Hehe, I took so long in my reply, you'd edited your post

I wouldn't try to run it from a molex connector from within a running PC, well, not with a 300W PSU anyway. And a 30 degree temperature rise will make it too hot to touch (I have soft hands!)

I think we need more details of what you want to do.

 

[EvanVanVan]

Hmm, yeah, well it's a Pioneer AppRadio2 (that I can connect my Galaxy Nexus to). And I'd like to play around with it, but am not ready to complete the install into my car (missing a usb splitter and new MHL cable I've ordered off Amazon).

And the desktop PC is basically a server for our business, so I can't really shut it down for extended periods at a time. That's why I'm trying to come up with workarounds.

My first thought was just a power cable from common household applices (the little black box at the outlet). One I found has an output of 12V but only 2A max...I took it apart and found the 2A fuse inside, but I'm assuming I can't just change that to a 10A fuse to increase the max current output...

edit: how about stripping a section of the yellow 12v PSU wire before it reaches the motherboard and taking the power from there instead of the molex? Although, the problem is more likely trying to power the PC and radio together instead of where the power's coming from

 

[weird_dave]

Trying to use the PC and radio from the same PSU is not a good idea, especially since you rely on the PC for business. You'll struggle to find a 'wall wart' that can give you 10A, however, if you don't turn the volume up too much you may get away with a 2A one to at least try it out. Do you have a multimeter?

 

[EvanVanVan]

Thanks for you help, there's a computer recycling place near me and they have PSU's for sale for $10 so I'm just gonna pick up a second one today. It's now the first time I've been looking for an easy, external 12v or molex power source.

Thanks again