This one differs by using an Arduino to read from the metal detecting coil. The circuit starts with an oscillator that produces a signal of about 160 kHz which is constantly measured by the Arduino.

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 ...

An advanced metal detector coil encompasses the diameter of the sensor head. Passing current through the MD coil creates an electromagnetic field that induces an electrical current in any metal ...