Over on YouTube our hacker [VIP Love Secretary] shows us how to make a simple MOSFET tester. This is a really neat, useful, elegant, and simple hack, but the video is kind of terrible. We found that ...

When working around mains voltages, it can be useful to know whether a given circuit is live or not. While this can be done by direct connection with a multimeter, non-contact methods are available ...

There have been many different ideas presented for increasing the acoustic output of a piezo buzzer or ultrasonic transducer. Most of them involve rather complicated circuitry that drives up the total ...