Electrical Engineers, I need help!

Ok, I know just enough about electricity to kill myself in the proccess of trying to experiment. I'm installing a water cooling system into my computer and I've opted to use the DangerDen 12v Waterpump. This water pump only has a regular molex connector (12v is what the are, right? Told you, didnt know much.) and I would like to make it so that instead of using it pluged into the PSU, I can plug it into the wall and have it constantly running. Any help on this issue about splicing and converting would be much apreciated.

Thanks!

_________________________
Death From Above
"The Legion"

AIRBORNE!

What would be the advantage of a constantly running pump? There shouldn't be a need to draw directly from the house line.

Yes, I can see no advantage in drawing straight from the wall or having it constantly running. Why cool a computer that isn't on? What do you gain? Doing what you're thinking would require more work than you might realize. Apart from just adapting the connection from the PSU connector to a standard outlet, you'd also have to convert A/C to DC and use a transformer to reduce your 120V wall outlet to the 12V you actually need. This could be done through a universal AC adapter, but it still wouldn't be safe. Your PSU has protections to filter out spikes in current that an AC adapter would be inadaquate at providing.

Are you just worried about drawing too much current from your PSU? If so you can calculate how much power you're using by looking at all of the labels for your various devices and then summing up the watts (plus about 3-5 Watts per fan). As long as you're total is less than the PSU's watt rating (plus a buffer of about 20 Watts) then you're okay. If not, I'd fork out the money for a better PSU rather than attempt what you're thinking of attempting. Or perhaps have you ran out of connectors on your power-supply? You can buy Y-adapters at any computer store for a couple of bucks.

Irregardless of whether it's coming from the PSU or the wall outlet, you're going to be drawing just as much current from you're circuit. Unless you happen to know that the two outlets are on different breakers.

If you still want to go ahead with you're scheme, here is some info. The molex connector you referred to actually has two different supply voltages. The red wire and black wire next to it are for a 5V circuit (a rail voltage). The yellow wire and the black wire next to it are for a 12V circuit (as you mentioned). It sounds like you'll probably just need the yellow circuit (I could be wrong, but I highly doubt it). How can you tell. Does the pump have only two wires coming out? If so you only need the 12V circuit. If you go to radio shack and purchase a GOOD universal AC adapter (don't go cheap on this) and set it at 12V and tape it there, you could cut off the connector on the adapter, and the molex connector. splice the power to the yellow wire from the molex and the ground to the black wire. Then tape up the other two wires from the molex, to ensure they NEVER touch anything else. If you're system does, in fact, require the 5V rail voltage as well (which I doubt) you would need to buy another AC adapter, set it for 5V, and do the same for the red circuit. Then plug both of these into a GOOD surge protector.

If you don't want to cut the molex connector off, you can get the same pins used with the molex at radio shack as well and then crimp them on to the ends of the wires on the ac adapter.

Again, may I advise against doing this unless you're willing to risk ruining your water cooler.

I just realized that if there are only two wires in the molex, they will probably be red and black (not yellow). It will still be 12V. Sorry about that.

Well, I'm really liking this forum business as I can find answer to my questions a lot faster than trying to search for them on the web. I want to say thank you to both of you for getting back so quickly and helping.

As for the reason why I wanted to put it on it's seperate power sorce is because from what all I've been told it's better to keep teh pump constantly running instead of leaving the water stagnent in the lines. I'm not planning on using a regular water combination, but a replacement (yes, I know it's not "AS" great of a heat conducter, but it's designed for PC cooling.)

I do not plan on turning my computer off much, but when I do, (say if I go on vacation for a while) I rather not leave it on the entire time. Granted it's probably not good to leave the pump on the entire time incase for some freakish reason it decides to piss all over the innards of the computer, but oh well.

From what you're saying I guess it's just easier to leave it as it is and keep it hooked to the PSU. I really doubt I'll have a wattage problem as I'm getting a 510W PSU. I'll deffinatly take your advice and just keep it as it is. It'll probably be too much of a hassel.

Thanks again!

__________________________
Death From Above
"The Legion"

AIRBORNE!

I'm glad we could help you out. Yes, if you have a 510W PSU, it would be very difficult to overload it.

Interesting about keeping the pump on. I've never tried water cooling and therefore had never heard this before. Now that you say it though I guess it would make sense. I'll have to learn more about it. Thanks for your info.

That's why I bought one that runs off of 120V naturally. Although my computer is on damn near all the time, those periods where I'm on the road somewhere, I'd rather have the water continue to circulate in my system. However, it's not that big of a deal. Worst case scernario, you change the water when you get back. Minor details.

If you were really concerned, I'd just get a different pump.

How about using a charger from a 9.6v remote control car battery? Mine has an output of 11.6v dc. I'm not sure how close you need to be or anything, just wondering.

I don't know how much voltage it would be able to provide under a load. Probably only a little above 9.6v since that would ba trickle-charge for the battery. A better bet would be to use another PSU dedicated to the pump and maybe a fan bus. Additionally, he could put that PSU on a timer circuit so that it would go circulate the water for so long every day and conserve a little electricity, a financial must out in California.