Thread Tools
Old Jan 07, 2009, 02:34 PM
byrocat is offline
Find More Posts by byrocat
Registered User
byrocat's Avatar
Discussion

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?
Sign up now
to remove ads between posts
Old Jan 07, 2009, 04:58 PM
Pete Miller is offline
Find More Posts by Pete Miller
Registered User
check it out!

http://web2.murraystate.edu/andy.bat...owersupply.htm
Old Jan 07, 2009, 07:12 PM
lake flyer is offline
Find More Posts by lake flyer
Registered User
lake flyer's Avatar
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 .
Old Jan 07, 2009, 07:25 PM
cyclops2 is online now
Find More Posts by cyclops2
Registered User

How many volts & amps do you use / need ??


Riding mower battery or a auto junkyard cheapy from the next wreck. $ 5 to 10.
Old Jan 07, 2009, 07:34 PM
byrocat is offline
Find More Posts by byrocat
Registered User
byrocat's Avatar
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.
Old Jan 07, 2009, 08:03 PM
cyclops2 is online now
Find More Posts by cyclops2
Registered User

Oh yeah ?


You should see how many screws my cordless can drive when it is connected to the riding battery.
Old Jan 09, 2009, 02:42 AM
rich smith is offline
Find More Posts by rich smith
7000mw of raw power!
rich smith's Avatar
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 .
Old Jan 09, 2009, 09:16 AM
cyclops2 is online now
Find More Posts by cyclops2
Registered User

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
Old Jan 09, 2009, 09:23 AM
bracky72 is offline
Find More Posts by bracky72
Questionable judgement
bracky72's Avatar
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.
Old Jan 09, 2009, 09:28 AM
cyclops2 is online now
Find More Posts by cyclops2
Registered User
Bracky is right. Most switching supplies need a " Minium holding current. "
Old Jan 09, 2009, 08:09 PM
Joel Shreenan is offline
Find More Posts by Joel Shreenan
Registered User
Joel Shreenan's Avatar
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.
Old Jan 09, 2009, 08:21 PM
rich smith is offline
Find More Posts by rich smith
7000mw of raw power!
rich smith's Avatar
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
Old Jan 10, 2009, 10:49 AM
Iranair is offline
Find More Posts by Iranair
ShahBaz
Iranair's Avatar
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
Old Jan 10, 2009, 11:31 AM
rich smith is offline
Find More Posts by rich smith
7000mw of raw power!
rich smith's Avatar
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


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion $35 12.6V 6600mah Power for LIPO charger hall woo Batteries and Chargers 1 Nov 25, 2008 07:53 PM
Question Power for battery charger from 36v?? staib Batteries and Chargers 2 Nov 14, 2004 12:39 PM
Question PC power supply amperage for Apache charger?? brian2kgt Batteries and Chargers 5 Dec 04, 2003 04:41 AM
Question Power supply watts for a charger? Cush Batteries and Chargers 9 Nov 10, 2003 07:26 AM
Using a computer power supply for DC power for charger... T-Bo Electric Plane Talk 13 May 11, 2002 02:45 AM