Back in the early days of electricity, lab workers could measure electric current in a circuit using an ammeter (galvanometer) and voltage using a voltmeter. From there, they could calculate ...

While using a digital multimeter to diagnose electrical problems on customers’ equipment, I frequently hear the comment, “I’ve got one of those multimeter things, but I never learned how to use it.” ...

Our hacker [John Duffy] wrote in to let us know about a video he put together to explain the design of his open-source multimeter, the HydraMeter. If you’re interested in how the circuitry for a ...