12 volt Power Supply

Hello all,

I'm sure this answer is hidden among the posts but I looked and looked. So here goes...

First project with Arduino and do not want to fry the board...

I have an Arduino Uno Wifi Rev2... i want to power it with a DC power supply into with the 2.1mm adapter on the Uno board. The supply puts out 12.35 VDC according to meter. The scope shows a nice flat, no ripple, filtered DC voltage as well. I plan to digital "write" one opto-isolated relay and "read" one current analog input.

I know the specs say 6-20 and i also know alot of people say 9volts is the sweet spot... I am just wondering if this will overheat the regulator? Power consumption as I intend to use "right now" is rather small... Maybe worry more as I expand the use of the board in the future or....

Thanks alot

I recently did a project that ran on an Uno. The Uno was powered with a 12V wall-wart into the 2.1mm plug. The 5V pin was powering a Wemos D1 Mini. It would run for several hours with never a problem and the regulator was always cool to the touch.

But, for 24/7 use, I would use a 5V regulator from the 12V supply and power the Uno through the 5V pin.

Here’s the regulator I use:

Or, better yet, just get a good 5V supply.

tobsun.jpg

SteveMann: I would use a 5V regulator from the 12V supply and power the Uno through the 5V pin.

But OP has an Uno Wifi Rev2, not an Uno. The only similarity is the size and the wrongly chosen name.

The Uno Wifi Rev2 has a built-in buck converter. Not sure why they put 7-12volt in the specs. The MPM3610 buck chip has a >20volt rating. The input cap might be 16 volt??

12.35volt on V-in seems fine. Leo..

Thank you for the piece of mind...