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 ...

Researchers at the University of Stuttgart have developed an “optical sieve” for detecting tiny nanoplastic particles. It works like a test strip and is intended to serve as a new analysis tool in ...

This simple 4093-based audio peak detector from December 2004 monitors music and turns on a small light when the sound gets ...

Researchers have developed a new optical sensor that provides a simple way to achieve real-time detection of extremely low levels of arsenic in water. Researchers have developed a new optical sensor ...

This circuit is suitable in every situation where over-current protection is required. Here we give an example from the model train world. Every seasoned model train enthusiast knows that there is ...

This simple circuit helps you sniff out RF radiation leaking from your transmitter, improper joints, a broken cable or equipment with poor RF shielding. The tester is designed for the 2-m amateur ...