In a world of digital monotony, the Avo DA14 digital multimeter, with its vintage nixie tube charm, is a refreshing gem. Recently refurbished by [Thomas Scherrer], this multimeter video review is ...

That’s true enough — if you consider a voltmeter and a Mark 1 eyeball to ... so a simple circuit was built to select an LED from the somewhat grandly named “photon energy array” and ...