Modern digital multimeters (DMMs) are user-friendly, accurate, and safe — when used correctly! Reading voltage is simple, but ...

It’s a circuit you’ll find all over the place, even built into many modern multimeters. It can be particularly useful to help avoid drilling through mains wires embedded in the walls of your home.

Of course, sometimes that older hardware needs a little TLC to keep it running in the modern world. [Lex] had a beautiful vintage multimeter that sadly had a broken screen, and set about a nifty ...