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Old Jan 07, 2009, 02:34 PM
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byrocat's Avatar
Aurora, Ontario, Canada
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Converting a computer power supply to supply power for a charger and 12V equipment

I've got a "Delta Power" 500ATX switching power supply and can remember that someone's done some conversion jobs on such so that you can power chargers or other 12V equipment.

Someone did tell me about Radio Shack having a ready-made unti
http://www.radioshack.com/product/in...entPage=search

However, I've got the power supply and can do the conversion.

I believe that it's merely hooking in to the correct power points and the installing banana jacks into the case.

Anyone done this and can point me in the correct direction?
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Old Jan 07, 2009, 04:58 PM
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Beaumont, TX
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check it out!

http://web2.murraystate.edu/andy.bat...owersupply.htm
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Old Jan 07, 2009, 07:12 PM
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I used one for a couple of years , just find the 12 volt outputs and the neutral and you are in business , but a battery is better , that's what I use now .
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Old Jan 07, 2009, 07:25 PM
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United States, NJ, Frenchtown
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How many volts & amps do you use / need ??

Riding mower battery or a auto junkyard cheapy from the next wreck. $ 5 to 10.
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Old Jan 07, 2009, 07:34 PM
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Quote:
Originally Posted by cyclops2
Riding mower battery or a auto junkyard cheapy from the next wreck. $ 5 to 10.
Ah, Cyclops. I need to run the charger in the basement as well as having some 12V tools and fans that need to be run off of it as well.

Adding a battery in the system makes it difficult to move around and set up.
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Old Jan 07, 2009, 08:03 PM
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Oh yeah ?

You should see how many screws my cordless can drive when it is connected to the riding battery.
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Old Jan 09, 2009, 02:42 AM
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Not true. You must also ground the green wire or supply never turns on. IMO charging a battery with a battery is just wrong!

Quote:
Originally Posted by lake flyer
I used one for a couple of years , just find the 12 volt outputs and the neutral and you are in business , but a battery is better , that's what I use now .
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Old Jan 09, 2009, 09:16 AM
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Rich Smith.

At NO TIME is a green or bare wire EVER to carry operating currents !!!!!!!!!!

What has happened to that supply, is that the green & the neutral have been swapped ACCIDENTLY by the factory or someone after them.

The electrical codes in the U S A .....DO NOT allow green to carry any currents. It is there to prevent living plants and animals from being shocked in a screwup.

Rich
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Old Jan 09, 2009, 09:23 AM
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No one has mentioned that computer power supplies regulate their voltage according to the load on the 5 volt rail. You need to put some resistance across it to get adequate voltage on the 12 volt side. I use 3 of the biggest ceramic resistors that RS sells.
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Old Jan 09, 2009, 09:28 AM
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Bracky is right. Most switching supplies need a " Minium holding current. "
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Old Jan 09, 2009, 08:09 PM
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Pete Miller's post (#2, above) has some very good photos of how to install the required load resistor and binding posts on the PC power supply's case.

And here's a link to a very good explanation of how to convert a PC power supply for powering your 12V battery charger. It includes a good explanation for why the 10 Ohm, 10W resistor is needed for creating a load across the 5V power supply circuit. Connecting the green ground wire to one of the black ground wires tricks the power supply into thinking the power supply is connected to a motherboard.

This is the best explanation of many I've read about converting a PC's power supply for use in charging hobby batteries.

Enjoy -- Joel.
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Old Jan 09, 2009, 08:21 PM
7000mw of raw power!
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New Hampshire (not the old one)
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You are confusing the green power good signal on the ATX connector with a green 110vac cable. There are no 110vac wires present on a PC ATX supply which uses a UEIC connector instead. You MUST short the green wire or the supply simply don't work. Read at least one of the links above.

Also note that 5v load is necessary on very few units and even then only if you draw current from 12v line close to the limit. The dozen of so supplies I've converted do not need a 5v load. Check before you go through the hassle.


Quote:
Originally Posted by cyclops2
At NO TIME is a green or bare wire EVER to carry operating currents !!!!!!!!!!

What has happened to that supply, is that the green & the neutral have been swapped ACCIDENTLY by the factory or someone after them.

The electrical codes in the U S A .....DO NOT allow green to carry any currents. It is there to prevent living plants and animals from being shocked in a screwup.

Rich
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Old Jan 10, 2009, 10:49 AM
ShahBaz
Iranair's Avatar
Joined Aug 2008
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Quote:
Originally Posted by jonesymj
Well here's how I've done mine... Nothing expensive as far as the power supply goes, but it's held up for a couple of years now running my little Hobbico dual battery charger... Although at best I'm probably only pulling 5A out of it, so it should last forever...

Quick and dirty photo instructions...
Hi Jonesymj

I wish you had some pictures of the process you went through. I have
opened mine(Pc power supply), and i just cant understant why there isnt any el. in there!!?
I am in need of some good instruction in how i can go about this problem.

any idea???

Thank's
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Old Jan 10, 2009, 11:31 AM
7000mw of raw power!
rich smith's Avatar
New Hampshire (not the old one)
Joined Dec 2006
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You should never have to open a PC supply to do this.

BTW what is el. and why are you looking for one?


Quote:
Originally Posted by Iranair
Hi Jonesymj

I wish you had some pictures of the process you went through. I have
opened mine(Pc power supply), and i just cant understant why there isnt any el. in there!!?
I am in need of some good instruction in how i can go about this problem.

any idea???

Thank's
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