If your goal is to save on electricity, you must first measure the ac current flowing through your appliances. The formula for power is the product of the ac line voltage and the measured current.

The easy way to measure high AC currents is to use a clamp meter but these are generally quite expensive and cost several hundred dollars at a minimum. Add-on clampmeter adaptors can work well but ...

A decent current measurement sensor ought to be an essential part of every hacker’s workbench. One that is capable of measuring DC, as well as low and high frequencies with reasonable accuracy. And ...

A specialized test gadget that tests continuity quantitatively in both AC and DC modes could prove to be an indispensible bench test instrument. This article describes such a continuity test set up, ...