How to build a $20 47A power supply - Page 10 - RC-Monster Forums

DrKnow65 · 01.08.2011, 08:16 PM

So I've been trolling eBay looking at supplies. Specifically ones that look to have good 12v amperage that I could use in series to get 24v, what I'm drawn to are the X0551 Dell server units (47.5a at 12v). Aside from the complexity of safely connecting them in series do you guys see any reason why these would not work?

Metallover · 01.08.2011, 08:30 PM

As long as you have a way to turn it on, it should work great.

SunnyHouTX · 12:05 AM

I don't know why I took this long to do this but I finally got me a 47A PS off the bay for a few cents under $18 shipped. It's going to replace my 26A ATX PS which still works and I will use for truing tires and such at home and as a backup. I was blown away by how small the server PS compared to the ATX PS and I really like the form factor as it makes it easier to carry it and my other CellPro 4S chargers to the track in one Pelican case on race day. It registered 12.58V with no load after I cranked it up.

Thanks to Snellemin and others who've contributed to this thread. Now I wait for my PL8 to show up so I can start working on my LiPos for the 2011 race season. Looking forward to the first ever 1.1s ET on 3S in 1/10 electric TF drag racing.

kazuaki · 01:45 AM

So, here's my "Charging Box" that I recently completed. I used the HP 47A server power supply and cranked it up to output 13.4V. While I was tweaking inside the power supply, I rewired the fan to run off the 5V output, so it's much quieter. So far, it still stays plenty cool. I put it into a modified Plano tackle box with a pair of iCharger 206B chargers (capable of charging at 20A each). I added a socket on the outside of the box for a detachable power cord. I had previously modified the power supply with a toggle switch, so that powers the whole thing up. There is a ton of space for all the miscellaneous charge leads and balance adapters. And finally I added an LED volt meter because I thought it looked cool

So far, I'm really liking this setup.

ANGRY-ALIEN · 02.01.2011, 02:04 AM

very cool... well done on that installation

... been wanting to do something similar with the pair i have... what voltmeter is that? where can i find them?

Alien

kazuaki · 02.01.2011, 04:04 AM

Quote:

Originally Posted by ANGRY-ALIEN

what voltmeter is that? where can i find them?

This is the one that I bought:
http://cgi.ebay.com/ws/eBayISAPI.dll...m=230363049931
There are many out there that would work, but be careful as a lot of them require a 5V power supply.

George16 · 02.01.2011, 04:37 AM

Very nice.

ANGRY-ALIEN · 02.01.2011, 08:38 AM

Quote:

Originally Posted by kazuaki

This is the one that I bought:
http://cgi.ebay.com/ws/eBayISAPI.dll...m=230363049931
There are many out there that would work, but be careful as a lot of them require a 5V power supply.

Oh.. thanks for the link and advice man... I'll do some searching again for suitable boxes that will fit all my charging/electric field gear and work on the install... will post up some photos when I'm done.

Alien

DrKnow65 · 02.01.2011, 10:29 AM

Kazuaki, I think you've hit on a really good idea there

Hope you're ok with the shameless copying of your idea, because I'm all over that

Good job!

snellemin · 02.01.2011, 10:40 AM

I like this tackle box idea. I too shall shamelessly copy this.

kazuaki · 02.01.2011, 11:12 AM

Quote:

Originally Posted by DrKnow65

Kazuaki, I think you've hit on a really good idea there

Hope you're ok with the shameless copying of your idea, because I'm all over that

Good job!

Not a problem at all, that's why I shared it. One thing I just realized...it kinda looks like a bomb

So, be careful going near federal buildings or airports with it...

BrianG · 02.01.2011, 11:17 AM

I too like the idea. However, if I might make a suggestion: To minimize power wire flex every time you open the box, how about mounting the chargers to a false bottom right above the PS? That would give you more room to store your adapters and provide a larger lipo tray for charging.

BTW: I see you were able to get a good stable 13.4v. What resistors did you end up using in the feedback circuit?

kazuaki · 02.01.2011, 11:53 AM

Quote:

Originally Posted by BrianG

BTW: I see you were able to get a good stable 13.4v. What resistors did you end up using in the feedback circuit?

I ended up settling on 200ohm on the positive side and 22ohm on the negative side.

lincpimp · 02.01.2011, 11:54 AM

I did something similar a while back. Not as nice, but it worked.

kazuaki · 02.01.2011, 11:56 AM

Quote:

Originally Posted by BrianG

To minimize power wire flex every time you open the box, how about mounting the chargers to a false bottom right above the PS?

That would work, but I guess I didn't see the wire flex as much of an issue.

BTW, for those that go looking for a tackle box, most of the ones big enough to hold the server PS will be 3 tray boxes. This one had 3 trays, but I removed the top tray. They disassemble easily.