[vonPongrac] stumbled upon this handy guide, a free eBook on 50 555 Circuits, which contains many cool project ideas, including a simple metal detector circuit. It’s a very basic concept that ...

For casual ESD detection, the “rubber duck” antenna (shown above) also works OK. The detector will sense ESD events within several feet and lightning within 2-3 miles. It makes a great tool when ...

On the other hand, precise detectors based on op amps are rather slow. They are therefore not well-suited for measuring pulses of a few nanoseconds’ duration. The circuit in Figure 1 offers both good ...

Circuit Combines DC High-Voltage Drop Detector, Undervoltage Alarm Dec. 14, 2010 Description of a circuit to tell if the high-voltage supply in an industrial smokestack precipitator is functioning ...