The metal detector circuit shown here must represent the limits of simplicity for a metal detector, yet the design works surprisingly well. It uses just one 40106 hex Schmitt inverter IC, a capacitor ...

[zaphod] had to research how a metal detector actually works. After reviewing the pros and cons of various approaches, the decision was made to go with a beat frequency oscillator (BFO) circuit.

A pulsed induction metal detector induces a current spike in its search coil, and times the decay of the resulting oscillation. The coil is part of a resonant circuit with a capacitor, and any ...

Cheap metal detector The working principle of this cheap and easy to build metal detector circuit consists in mixing two equal frequencies which causes a low-frequency interference. When one of the ...

The circuit creates an audible sound. Many metal detectors now have LCD displays that show their settings. Metal detectors can tell the differences between different types of metal based on how ...