parnelli97

iTrader: (6)

Is it possible to make an old computer power supply work as a power supply for my motor lathe, and a few other things I have that need power? The power supply says it's 400w @ 12v. That seems overkill but maybe I could make a circut to dial the amps up and down.

Evilstealth

iTrader: (3)

A computers power supply will run at way more amps than its rated, it wont overload it will just get hot

to convert a computers PSU use this:

http://www.rcracechat.com/vb/showthread.php?t=2129

If you need any help with anything just PM me

Dondor

iTrader: (2)

Pure PWNAGE. Thanks for the link.

The Don.

bb71

iTrader: (4)

Here's a link with photos. I've done this 5 or 6 times. They work great. MY bench supply and track supply are both smaller HP PC supplies. Some of the larger gaming / cad workstation type power supplies have 2 12V rails that are capable of 20-30 amps. They all have 3V and 5V rails too. Tons of juice!


http://www.wikihow.com/Convert-a-Com...b-Power-Supply

Brad

parnelli97

iTrader: (6)

http://www.wikihow.com/Convert-a-Com...b-Power-Supply

This has to be the best of them all, it's neat, well written, and excellent photos. Thanks, now to dig one out of the closet and do it.

bb71

iTrader: (4)

It's real easy. The first one might take you an hour. After that, you'll whip them off in 10 minutes.

parnelli97

iTrader: (6)

I want to do the variable voltage one that links of the previous one I mentioned, however it's limited to 1.5a and thats just no where near enough to run my lathe or truer.

Skruger

iTrader: (16)

http://www.qsl.net/yo5ofh/projects/1...r%20supply.htm

More time consuming but More amps if you'r Savy enough.

Skruger

iTrader: (16)

Just use the 3.3 Volt (Memory Power) ORANGE wires then. Heck My ATX 600W has 50 amps on the 3.3 Volty Side

convikt

iTrader: (27)

rule of thumb is for 100watt = 1 amp. Just keep that in mind

tc3team

If you wanted to, you can make youre own custom box and terminals for everything to sit into aswell (complete with spray job/decals etc) it just makes it all look real neat/trick

might need some vents though?

Evilstealth

iTrader: (3)

What rail is that rule referring to because i have a 550w PSU and it is rated at 19Amps on the 12v+ rail and the other rails (3.3, 5v) are way above this i think the 3.3v is 35Amps and the 5v is 45Amps, so i don't think that rule works unless i have got it wrong.


You could use a lamp instead of a resistor, i prefer a lamp because it doesn't get hot and it is very easy to swap if it blows also you know when its on , it is a personal choice though some people prefer lamps others prefer resistors either one does the same thing

bb71

iTrader: (4)

Disregard that. The rule of thumb is Ohm's Law. Power (W) = Voltage (V) x Current (I).

What you need to check first is what does the equipment you want to run require (voltage and amperage) and what is your PSU capable of providing. There should be a sticker on the PSU that shows what each output is capable of. There will be a 3.3V, 5V and 12V rail. Each will have its own amperage listed. The one on my bench is 28 amps for 3.3V, 30 amps for 5V and 15 amps for 12V. Its a 300W PSU. There will also be some - voltages listed but they will more than likely be very low amperage compared to the + side.

I can build you one for $25 including a quality HP / Compaq PSU (used but flawless) + shipping if you like.

joe of loath

iTrader: (1)

hmm should i make one of these, or just use the 5 amp 12v power supply in a nice neat black box?

oh and my PSU is BTX (old workstation. the motherboard arrangement means it can fit dual CPU's inside) i guess it will work for this?

bb71

iTrader: (4)

I use a large sandbar type resistor. I also tightly cable tie it to the heatsink already in the PSU and use some thermal paste between the two. I use an LED to show that the unit is on. I also use ATX supplies instead of the older AT type. The ATX supply has a switch built right in so you can leave it plugged in and turn it off and on.