Powering an Arduino Uno board with a -48v DC power plant

Other Hardware Motors, Mechanics, Power and CNC
1

I am looking to power my Arduino Uno with my -48v DC power plant I have setup in my data center. It's voltage is running around 50v-51v DC.
I use this power plant to power all of my Cisco Routers, switchs & a ONS 15454.
I would like to use this system because I have a 10-22 hour power up-time with the batteries I have on it. (4 x12v in series)

I am thinking I can use a cheap down step off of ebay to convert the volts from 48v (max input 60v) down to 12v, should keep the volts down so the input isn't fired out.

But my big question is the polarity, which side is now ground.
The way I under stand my power plant is that it's a positively grounded system.
My + side of my power plant is hooked to earth ground.
So if I switch the leads so that I have a +12v into the Arduino, I am hoping that will not fire out the system.

I am very good at firing things out because I don't ask questions before I go do.
And I would like to not throw $30 bucks out the window with a pretty light show with a smell that doesn't go away for a few days. :slight_smile:

Thanks,
~Russ

2

I would think at a minimum you would require a totally isolated DC to DC power converter. That isolates the Arduino ground from the power plant ground.

3

I think that these are isolated.
AT&T FE075C, 75W
http://www.bgmicro.com/48v18ain15v5aout.aspx
AT&T FW100C9, 100W
http://www.bgmicro.com/48v-2-5a-in-15v-6-7a-out.aspx

Same price ($10).
Comb the Internet for data.

4

Here's another one, definitely isolated, with 5V output: http://uk.farnell.com/xp-power/jca0248s05/converter-dc-dc-1o-p-2w-5v/dp/1289170. The 12V version is http://uk.farnell.com/xp-power/jca0248s12/converter-dc-dc-1o-p-2w-12v/dp/1289171.

5

Thanks for the info guys..

I can see a isolated power convert in my future :slight_smile:

~Russ