Wiring Schematic diagram

These metal detectors circuit is using TDA0161 monolithic integrated circuit designed for the detection of a metal body by detecting variations in high frequency eddy current losses. For metal detection requires an external circuit TDA0161 LC tuned.

The output signal is determined by changes in the current bid. Independent of supply voltage, this current is high or low by the presence or absence of a metal object nearby. Metal detector This circuit uses two LED indicators that provide a visual indication of the presence or absence of metals around the coil. To adjust the circuit need to make sure there is no metal near the coil and then set the fine tuning of a "middle ground". After that you need to adjust the course adjustment to turn the LED and adjust the fine tuning to turn off the LED.