I am looking at this power supply and trying to find out how many amps it puts out on 12volts.

Specs indicate that +12v is at 34amps then -12v is at 0.8amps.

How do you use this for RC chargers, do you just find out which wire gives out 12 volts and use that, Or is there something I have to modify to convert this for Rc applications.

Thanks in advance.

AC INPUT 115V/230V 10A/6A 60/50Hz
DC OUTPUT +3.3V +5V +12V -12V -5V +5VSB
500W Max
Combined
Watts 28A 30A 34A 0.8A 0.3A 2.0A
500W

[link=http://web2.murraystate.edu/andy.batts/ps/POWERSUPPLY.HTM]Clicky[/link]

I have not tried it yet(or even read the page), my buddy sent me this link, and said it worked for him.
I just grabbed a 12v power supply from my parent's lake house outdoor lighting system that they updated; I am hoping this works with no mods

Have you checked out this forum? There might be someone who's tried one?
http://www.rcuniverse.com/forum/forumid_84/tt.htm

I recall reading of guys using PC power supplies before...just don't recall that particular one?

Support RCU!

http://www.rcuniverse.com/forum/m_5680951/tm.htm

Like you said "Specs indicate that +12v is at 34amps." That means it can put out 34 amps at 12 volts.......Thats enough to run 9 chargers charging a 6 cell at 5 amps each!!!

Attatching the batery to any of the cores of this power suply will instantly destroy it. The reason is that it possibly has no Diodes to block the incoming current from the battery to the power suply. That's the basic difference between Chargers and power suplies. You need an extra circuit to make it work. With double diodes and ayto cut-off system at reverse polarities and when the battery is fully charged to avoid its destruction.

Heres what I did
BTW don't leave the connectors exposed, I had it soldered directly but then I needed to put the clamps back on so I could use it at the field

Hmm, maybe Deepfry Institute of Insanity did pay off...

Amps = watts/volts: Amps = 500/12 or 41 approx. So 34 is a safe bet. That is pretty high. I have a 25 amp PS from Pyramid. It never sees a draw higher than 5 or 6 amps, so you have lots of overkill. Looks like Hands has a good conversion process.

I prefer slow charging...always charges 5-10% more than the best quickcharger on the market.

That's cool. I was confused that the -12v is rated at 0.8amps

Thanks for the link, I have searched, and there is actually a lot of articles about this. I like this one better.

That was really not the plan.

Okay,

Got my power supply today. Plugged it in and turned it on, Nothing happens. Is this normal? Should the fan at least turn on? Or I need to short the sense wires before it would turn on?

I kinda want to know if the power supply is working before I continue converting it. So if its bad, I can return it. If I convert it and found out its bad to begin with, then I cant return it.

thanks,

Nope. The power supply won't work until you jumper (short) some of the supplies pins. I don't know which ones, but I know you need to do that. It is probably an ATX supply right? You should be able to google your answer.

That is probably a very clean and kick ass 12v source for a charger since 12v motherboard components are more sensitive to noise and spikes then our chargers are.

If you want to test it before opening anything try sticking one end of the resistor into a black wire terminal and the other end into a red wire terminal, and shorting a black wire and the green wire.

Ok, at first I shorted the wires as instructed in one of the tutorials....nothing happened.

Checked with a meter, no voltage, nothing.

Then it hit me...This is a PC PS..so I tested it on a PC... Happy to share that this $6.55 + $10 shipping Power Supply is working.

Now after reading other tutorials, I was able to find the correct wire to jump(short) to ground.

It turns on now with the switch, lights and fans, voltage is kinda low though specially when fan is turned up (adjustable) around 10.8v and 11.3 when fan is on lowest setting.

That voltage is probably still more stable and cleaner then the AC/DC converter in a charger.

I have to politely disagree there... My power supply stays at a constant 13.8v whether the load is zero or 10 amps. But I don't know if a constant 10.8v supply would cause a peak detect to false peak or not. That's getting pretty low, I'd say that's iffy at best.

It might be overkill, but this is what I use ($70 delivered when new, was on sale):

I have read that there is a way to raise the voltage by adding resistors. (Still searching) I have also read that you can combine the output wires to the voltage you needed. My yellow wires currently puts out 10.8v and orange wires puts out 3.0v so total would be 13.8v, just like a standard bench top power supply.

I am currently using a 13.8v Samlex 6 amp Power Supply which is just enough for 1 dc charger.

If sucessful 34amps from the converted PS would be Plenty.

Comparing the guts of the two power supply. The benchtop PS has bigger power caps and large transformer, while the PC PS has smaller power caps and smaller transformer. I kinda find it odd that the PC power supply gives out more amps than benchtop power supplies.

My concern was with the power drop on load. A little fan can't use much power - depending on what it is maybe 0.5 amps? A 5% or so power drop under such a small load raised a red flag for me. But, it could be anything. Maybe as you say, if you wire it for 13.8 it won't be an issue. I really can't say.

The yellow and orange wires will sadly give you 7.8v.

Read [link=http://web2.murraystate.edu/andy.batts/ps/TheFIX_java_table.htm]this[/link] to learn about ways to increase voltage.

I see, I forgot, You are right, thats what you do to slow down the fan if its too loud.

I guess I have to go with the resistor method.

Thanks for the help.

Finally done with my conversion project. Just want to share the experience.

Half of the casing of the PS is acrylic so there is no room to place the series of resistors that I needed to bump up the 12v output. Good thing I had another PS casing laying around. I just bolted the two together

Initial voltage reading was 10.8 v when the fans are running full speed and just a little over 11v at lowest setting.

I added 4 10ohm/10watt resistors in series to the 5V line and raised the 12v line to 12.8 volts. The resistors gets slightly warm only, unlike the 1ohm/10watt resistors that other articles have said. I tested those too and they get really hot within seconds and most likely would burn out. The resistors were mounted on a large heatsink on the bottom casing, I also added 3 fans on the bottom also wired through the 5v line to add as a load which also keeps the resistors cool.

Testing:

500 watts rating is for all combined (3.3v,5v, 12v) convert to amps = around 41amps. But if you add all the amp rating 28A 30A 34A 0.8A 0.3A 2.0A = thats 95.1 total. I dont think this is correct.

Calculating from the given amps and voltage for the individual power output = total wattage is 642.

But anyways, I compared it with my standard 6 amp power supply by using a 6amp dc charger. I checked the voltage readings on 6 levels of settings, 1amp,2,3,4,5 & 6. Using the standard PS, the voltage output incriments 6 times. from 8.5v,9v,9.5v,9.8v,10.2,10.5volts, but when I used the converted PS the voltage stopped increasing at the 4 amp charger setting. The output voltage remained the same 9.8 for the 5amp and 6amp setting. So by that alone, I can say the my converted power supply only gives out approximately 4 amps.

Good enough for 2 chargers since I never charge my batteries at 6amps anyways. So far I have ran 3 chargers at 2amps and 1 lipo charger that has a max output of 1amp all at the same time. Charging times might be a little longer than when using your standard power supply or car battery.

Looks great. Thats strange how at first you were only getting 10.8v. Was that reading from your 12v post? That doesnt make sense that it only gives out 4 amps. Mine puts out 16 amps at the 12v rail. Most power supplys give out at least 6-7 amps.

Also, I noticed the same problem with my resistor. It got really hot in only a couple of minutes. I then noticed when my PS was running my charger, the resistor only got a little warm even after a couple of hours. The resistors only get hot when nothing is pluged into the PS.

This is some strange math but I'll admit that its been a while since Highscool math and electronics classes, but the last time I checked 9 X 5 = 45 IF you run 9 chargers at 5 amps with a 34 amp power supply you come up 11 amps short, or you could run 6 chargers at 5 amps and have 4 extra amps.