@gunrunnerjohn posted:... never know when a project like this will come along and you'll need isolated power sources.It's the same reason I have a host of opto-couplers of various styles in stock, many of my newer projects are sporting opto-isolated inputs to totally eliminate the issues of common grounds and the like.
John, I'm getting started on a similar variation of this project (using these same led meters) and have a question about the isolated DC power supplies you used. I'm familiar with multiple ground loops and path length differences causing issues in unbalanced audio circuits.
In this Universal Meter Project you created, what issues might one have if only using a single isolated 5VDC source to power one each, of these Ammeters and Voltmeters connected in the same test circuit?
