The Arduino has a built-in regulator and some filtering so you can hook the (nominal) 12V supply to the Vin pin and expect it to work. If it doesn't work to your satisfaction, add more filtering.
The Arduino has a built-in regulator and some filtering so you can hook the (nominal) 12V supply to the Vin pin and expect it to work. If it doesn't work to your satisfaction, add more filtering.