Building a 12V DC Converter from PC Power Supply

1972 Views 17 Replies 7 Participants Last post by chuckyteets, Dec 3, 2004

rcairnut

Discussion Starter · Oct 10, 2004

2

First this is to power an Apache Li-Poly 1500 charger.
This can be used with other Chargers but "your mileage may vary"

This is for a 145 watt PS, the resistors I wanted to try for a 235 watt were not availed in this Hick town. :x

I will tell what I used and how I did it,

1. Power supply 145 watt ATX out of an old gateway p/c. This should yield about 4.2A max. @ 12V.
2. 2 (two) 1-Ohm 10 watt Wirewound Resistors Radio Shack 271-131.
3. 1 SPST Toggle Switch Radio Shack 275-324.
4. 1 set of Binding Posts Radio Shack 274-662.

Total cost with a free power supply is $7.37 plus tax.

See less See more

1 - 18 of 18 Posts

rcairnut

Discussion Starter · #2 · Oct 10, 2004

2

Next;
Leave 3 black wires -- switch, load resistors and (GND) binding post

Leave 1 red wire -- load resistors

Leave 1 yellow wire -- 12 volt binding post

Leave the green wire -- power on switch

Leave more wires if you are using a bigger PS like 300+ watt,
and you would need a differant resistor setup as well.

See less See more

steener

· #3 · Oct 10, 2004

Looks good rcairnut but, does it work. :lol:

rcairnut

Discussion Starter · #4 · Oct 10, 2004

2

Next;

I am using the resistors in a series to "over drive the PS" this will bump the output to about 12v the normal PS gives about 11.75v and this can cause an issue with some chargers.

This is at a thermal cost, we can deal with.

See less See more

rcairnut

Discussion Starter · #5 · Oct 10, 2004

3

And Next;

To dump the heat we need to mount the sandbars (the resistors) in good contact wit the PS case, find the smoothest sides on the sandbars. Zip tie them into the air vents, make sure they fully contact the PS (sand or file any flashing to make it work) and use some heatsink compound. Bum some from a geek buddy; you could borrow mine if you live close

(signed the geek).

See less See more

rcairnut

Discussion Starter · #6 · Oct 10, 2004

2

Next;
Wire and assemble. :rockon:

See less See more

PaulSwany

· #7 · Oct 10, 2004

Duuude!! That kicks ass..... Nice work and great pictorial...

rcairnut

Discussion Starter · #8 · Oct 10, 2004

2

steener said:
Looks good rcairnut but, does it work. :lol:

No Smoke

No sparks

No fire 8)
Working @ 11.99v to 11.98v resistors running warm.
:rockoncool:

See less See more

rcairnut

Discussion Starter · #9 · Oct 10, 2004

PaulSwany said:
Duuude!! That kicks ass..... Nice work and great pictorial...

Thanks

It has taken some burrito building time from me but I was still bitting glue off my fingers from my last incounter with that mexican lady. :lol:

I hope it is usefull to some, the best bet is to throw $100 at it and get a radio shack one,
25-Amp Switching DC Power Supply, Catalog #: 22-510 Model: 22-510;
but I am to broke to pay attention. $8 is more my speed, And I can buy a MoJo with $100!

steener

· #10 · Oct 10, 2004

That looks really proffesional. That thing really has one hell of a cooling fan. I think mine is about half that size. Good shit dude.

Heres my shit camera for ya

See less See more

rcairnut

Discussion Starter · #11 · Oct 16, 2004

steener said:
That looks really proffesional. That thing really has one hell of a cooling fan. I think mine is about half that size. Good shit dude.

Heres my shit camera for ya

Thanks a lot steener, I think if it works and it don't get hot the fan is big enough.

Spaz

· #12 · Oct 16, 2004

Heres my shit camera for ya

i bet it would work better with the lights on

just bustin balls, dont get pissed your tats scare me :lol:

jimross (aka Cool Pig)

· #13 · Nov 17, 2004

I got my hands on a NEW ATX style power supply (FREE), has removable cord and switch on back, and after all the surgery and figuring out where to put the jumpers to make it come on, the minute I put a load on it, it cuts off. Found out it needs a load on the +5 volt line to make it put out anything. I used a 14 volt bulb in a socket that only illuminates dimly when the power comes on. That way I know I have power output and it serves as the load also.
Just finished charging my Rx and Tx packs with it and it works great. Right now it is charging my glo igniter battery.

My PS is rated at 12 VDC 12 Amps so I don't think I'm gonna be ovrdriving it any time soon, and man is it quiet.

Dipshits at the computer shop wnated $25.00 for a used power supply, Hah! guess I showed them jerks.

smallfly

· #14 · Nov 17, 2004

It's 15 bucks but it takes all the work out of it
http://mcm.newark.com/NewarkWebCommerce ... -10081&N=4
I have an older one without the switch and it works great. I just use a 4 pin computer drive type connector (male/female) on one of the 12v outputs

chuckyteets

· #15 · Nov 24, 2004

thanks for the thread, mine works great!

the resistors seem to get slightly more than warm, but it doesnt seem to be hurting anything

i wonder why the thumbnail isnt my picture, thats weird...

See less See more

steener

· #16 · Nov 24, 2004

spastic said:
Heres my shit camera for ya

Click to expand...

i bet it would work better with the lights on
just bustin balls, dont get pissed your tats scare me :lol:

Those little tats. That was just the beginning. Its almost as addicting as profiles. Just try one.

rcairnut

Discussion Starter · #17 · Nov 25, 2004

chuckyteets said:
thanks for the thread, mine works great!

the resistors seem to get slightly more than warm, but it doesnt seem to be hurting anything

Thanks for the complement,
What size is the P/S you converted? If it is 235 or larger a different resistor setup would be better, but on a bigger P/S the worst that can happen would be the sandbars would fail and need to be replaced sooner.
BTW "Warm" to me means they will not burn you instantly, I was a baker for over 20 years, and my consept of hot may not be most pepoles, (some say I'm burned out :lol: )

I have an idea for a resistor setup for 235 to a 350 watt conversion (that will give good voltage and not burn up the resistors), but I have not tryed it so I did not include it, I just included what I know worked well.

Another use for a p/s conversion.
This old lcd monitor's ac power addaptor failed and they are no longer avalible, so........

See less See more

chuckyteets

· #18 · Dec 3, 2004

mine is a 200 watt, its sweet

1 - 18 of 18 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.