FrankenPower! Building a 12V Power Supply

[Mike Bargman]

I've got a 260 to fund...I'm saving every bit of money I make. LOL!

[paffy]

Have you actually tested the maximum load from this power supply ?

I found that they usually fall very short of the specs on the 12Volts. My chargers are often crapping out once you hit 80 Watts or so.

[Chris Puckett]

Paffy what are the specs on your power supply? The one I went with is very large and should not have any problems with what I am going to throw at it. Mine can handle 432 watts on the one 12 volt output.

[Boulder]

Hey Mike,

I'm going to de-solder all of the unnecessary wires off the board. Do you think there will be a problem taking all of the yellow clusters off except the one I need, or should I use 1 wire from each pin?

[Mike Bargman]

	Quote: Originally Posted by Boulder
	Hey Mike, I'm going to de-solder all of the unnecessary wires off the board. Do you think there will be a problem taking all of the yellow clusters off except the one I need, or should I use 1 wire from each pin?

I would keep 1 wire from each pin. Most of the boards are parellel systems, so it "shouldn't" matter, but all the other wires can be removed. Just remember the green wire for the switch...Post some pics when you're done!

[Mike Bargman]

	Quote: Originally Posted by paffy
	Have you actually tested the maximum load from this power supply ? I found that they usually fall very short of the specs on the 12Volts. My chargers are often crapping out once you hit 80 Watts or so.

Paffy,

I've personally run a 5-port Fromeco charger with each port charging at 2A. Plus, a Hobbico MKII charging at 1500mah with no problem. I think it would be hard to pop this thing...

Also, the one I was using was only a 300W at 20A Power Supply...this is 500W at 34A...He'll be fine...

[Boulder]

	Quote: Originally Posted by Mike Bargman
	I would keep 1 wire from each pin. Most of the boards are parellel systems, so it "shouldn't" matter, but all the other wires can be removed. Just remember the green wire for the switch...

I've already connected the green and grey together that were running to the main plug. Before doing this I made sure the grey had continuity to the black wires.

1 wire from each pin was my plan, just wanted to check with you first. I will also be utilizing 2 ports for +5V.

[Boulder]

One more thing, would there be any advantage to using multiple yellow wires to each 12V port?

[Mike Bargman]

I don't think so, Ken. I wouldn't see an advantage to it. The way it's done should be fine enough for what we're using it for.

[Boulder]

Thanks Mike,

I want to thank you for doing this on the site. It's inspired me to jump in and build one for myself, and I'm sure it's done the same for many members.

I have a friend that's done this before and I've always said, "I'm going to do that someday". Until you laid this on us, I never followed up...again, thanks dude!!!

I think these 12V ports will be enough to charge a battery, do you think I need to do anything different to one of them for this application? The battery I'm thinking of is a small gel cell, 7.5 amp., that I carry with me to run a charger in the field.

[Mike Bargman]

The only thing I'd be worried about Ken, is...How are you going to charge the Gel Cell from the power supply? Are you going to use a charger? I wouldn't hook it straight up in fear of charging the gel cell too fast, ya know? You would need a way to control the current. I use a FMA Direct Supernova to charge my hobby batteries...works great. That runs right off 12VDC.

[Mike Bargman]

By the way, you're welcome!

[paffy]

	Quote: Originally Posted by Mike Bargman
	Paffy, I've personally run a 5-port Fromeco charger with each port charging at 2A. Plus, a Hobbico MKII charging at 1500mah with no problem. I think it would be hard to pop this thing... Also, the one I was using was only a 300W at 20A Power Supply...this is 500W at 34A...He'll be fine...

I guess I had some real crappy PC power supplies then. IOTA-55 all the way

[Mike Bargman]

Unless you're charging a really huge pack at 30-40 Amps continuously, I don't think you'll have a problem. This is just a pretty practical and cheap solution to charging batts so you don't have to drag a field battery in the house...

[madmax]

You definately get what you pay for in the PC power supply world.. Most OEM boxes - dell, hp, gateway, etc, are pretty good. The el cheapo grey box power supplies are way more prone to failure.. Hey Paffy, I have a couple of 75 amp Network Appliance PS's in my garage, I might give those puppies a whirl! Thanks again Mikey, this is a killer thread!