# CPU Power Supply? Enough Amps?



## BoysinBoo (Dec 10, 2007)

Okay, I'm just about done with my stirring cauldron and rocking chair for the "Witches Porch". Both are driven by wiper motors. I've tried 12V (1A) and 9V (1500mA) wall warts, but both drive the mechs too fast. 

I have 5V supplies, but they are all low amps 350mA - 500mA. According to Scary Terry's site, he recommends at leats 2A for the 5V power. I do have an old CPU power supply that I'm considering hacking, but will it have enough current? 

Anybody?


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## CraigInPA (Sep 28, 2007)

Generally, any PC supply will put out WELL in excess of 2A at 5V. IIRC, even the oldest 65 watt PC supplies from the original IBM PC put out 8 or 10 amps of 5V. I suppose some of the newer supplies might be less, so check the label on the supply itself. Most are marked with the outputs and their rated capacity. 

One caveat, though, about using PC supplies is that they are switching type supplies. That means you must have a minimum load on them or they supply NOTHING.

I'll leave it to someone else to confirm whether you can run a 12V wiper motor at 5V, but I suspect it'll run once it's started, but it may not start at such a low voltage.

Craig


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## BoysinBoo (Dec 10, 2007)

Thanx. My problem is that I know just enough to be dangerous. So far this falls under the catagory of: "Well, lets see what happens".


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## scream1973 (Dec 23, 2007)

Yes you can certainly run a wiper motor at 5 volts or even at 3 volts. I have used a multi voltage wart to move some around..


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## haunted1 (Oct 3, 2007)

Yup - it'll work just fine.

I used an old PC Power Supply with a 12v wiper motor, and it ran great. Was quiet enought, and can allow for a few other Motors to be ran off it as well.

I cant remember the name of the site - I built my machine a year ago, but it shows you which wires to splice and bridge, and well as what to use for power. If I can find it, I'll post it for you.


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## Fetch (May 16, 2008)

Scary Terry's site has some info:

http://www.scary-terry.com/atxps/atxps.htm


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## haunted1 (Oct 3, 2007)

Yup thats the one! Thanks for that - I knew it had to be around here somewhere.


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## BoysinBoo (Dec 10, 2007)

I gutted four towers. The first two were e-machines. Not enough juice. The third is an old Dell Optiplex: Perfect. The fourth is a HP Pavilion 520: also Perfect. Thanx guys.

I'll be using one to drive two wiper motors. The witches porch should be done by the end of the month. I've still got to add the witches "spice rack" next to the cauldron, and a couple of other finishing touches. I'll post pics in the showroom after.


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