Hi All,

I got a hold of this PSU and couldn't find a how to on getting this supply modded for charger duties..

Anyhow, after some tinkering I Figured out how to do it.

It's pretty simple..
In this picture you can see the red/yellow leads soldered to the board.
That is the switched lead (for those that converted PC power supplies it's like the green wire).

However, I'd only get the supply to light up for a moment.
Putting a small light bulb on the 5V side kept it powered up.

After seeing the voltage drop to 11.4 w/ a 11-12A load, I decided to check and see if there was an adjustment pot. Found them both, and now with 11A I only drop to 11.9V.
The pots used are behind the fan on the edge connector side of the PSU.
There are two pots on the left, and one on the right. The ones to use are the upper one of the pair on the left, and the one on the right. Turning them both to full stop to the left gave me a 12.4V idle voltage and as stated above 11.9v @ 11amp.

Hope this helps others who can get this supply nice and cheap.



EDIT: The two leads used to power the unit on incorrect in my photo. The lead on the far left (red wire) just needs to be grounded.
After doing that, the supply throws down over 12A with out flinching (Steady 12.4-12.3v, before fixing the wiring it dropped to 11.9)

I'll upload new pics of my supply once I finish the rest of the mods.

awesome, detailed photos.

thanks!

btw: These are going for about 20 bucks on ebay.

What I like about it, is that it's nice and compact and pretty steady under load.

http://shop.ebay.com/?_from=R40&_trk...All-Categories

I killed me a HP 750 watt

I'll have to "find" another psu

Thank very much for this post, i was going to give up, I will give it a try

Originally Posted by PhotoGreg

Hi All,

I got a hold of this PSU and couldn't find a how to on getting this supply modded for charger duties..

Anyhow, after some tinkering I Figured out how to do it.

It's pretty simple..
In this picture you can see the red/yellow leads soldered to the board.
That is the switched lead (for those that converted PC power supplies it's like the green wire).

However, I'd only get the supply to light up for a moment.
Putting a small light bulb on the 5V side kept it powered up.

After seeing the voltage drop to 11.4 w/ a 11-12A load, I decided to check and see if there was an adjustment pot. Found them both, and now with 11A I only drop to 11.9V.
The pots used are behind the fan on the edge connector side of the PSU.
There are two pots on the left, and one on the right. The ones to use are the upper one of the pair on the left, and the one on the right. Turning them both to full stop to the left gave me a 12.4V idle voltage and as stated above 11.9v @ 11amp.

Hope this helps others who can get this supply nice and cheap.



EDIT: The two leads used to power the unit on incorrect in my photo. The lead on the far left (red wire) just needs to be grounded.
After doing that, the supply throws down over 12A with out flinching (Steady 12.4-12.3v, before fixing the wiring it dropped to 11.9)

I'll upload new pics of my supply once I finish the rest of the mods.

maybe a 10ohm 10 watt resistor might work in place of the bulb ? sorta like on the small ps when converting

Originally Posted by madatme

maybe a 10ohm 10 watt resistor might work in place of the bulb ? sorta like on the small ps when converting

I am running a 7Ohm 10w now. The light was temporary as my resisters were in the garage and I was being lazy. lol.


Glad to help!

I have got mine running and i used a 10ohm 10 watt resistor, seems to be ok so far. I mounted the resistor inside, by the weekend i will post a pic on what it looks like with the hardware

Originally Posted by madatme

I have got mine running and i used a 10ohm 10 watt resistor, seems to be ok so far. I mounted the resistor inside, by the weekend i will post a pic on what it looks like with the hardware

I got the ps up and running with attached hardware, in the 1st pic you can see the power resistor glued to the side in front of the fan, 2nd pic shows where the switch and posted are, be careful when choosing a spot so the hardware will have room and the cover will go back on( from the circuit board dimensions-switch 105mm x50mmx35mm offset see pic, red and black posts are 125mmx20mm all hardware from radio shack, 3rd pic shows the slot i cut out with a bench grinder for the wires(remove fan 1st) and used silicone sealer to cover the wires after the cover was put back on. Any questions let me know and thanks Greg and everyone for your help.

Update on how it works-the fans run slow and quiet, charged a 5s 3600 at wide open throttle and the voltage stayed close to 11.9-12v, the ps only got warm, temp gun says 95deg at the power resistor outside the case, did this for several batterys, so with 4 ps runnning at the same time there was not much noise at all-very happy with the results
glad to be of help and Thanks again
Greg B

Thats very cool Madatme, I may have to do something similar. Love how clean yours looks..

Originally Posted by PhotoGreg

Thats very cool Madatme, I may have to do something similar. Love how clean yours looks..

Greg, see my update and Thanks

Greg B

i have a couple of NPS-330AB power supplies i would part with for 100.00 shipped lower 48, they are unmodded. i was going to post tehm in the fs section but cant find the correct area as to where they should go

If your running the PSU in a small space, add the 5 volt line to pin 5
Diagram1{
|1|2|3|4|5| 6 | 7 | GROUND8 | 9 |5 Volt10|11|12|
}
The single pin next to the 12 volt line. is the fan "switch"

Can anyone identify the functions of 1,2,4,5,9,11 and 12 (number system is as defined in Diagram 1)

I'm running the PSU with 5R/20W in 5V line. At 12V line is 12,37V without load and 12,4V @ 16A.

Very happy

Okay, bumping up an old thread, but I just scored a couple of thes PS. Where does the 10Ω10W resistor tap into? one end is grounded, the other end goes to what pad on the output tabs?

Thanks,

Jon