The project described in this article is a ready-made item from a $2.00 shop! And it is made in China! It is a wireless doorbell with a cost of about $10.00. It is so cheap, you could not build it ...
The heart of this diy metal detector circuit is the CS209A IC. The metal detector is built with one 100µH coil that has 40 mm in diameter and is made of 50 turns/0.4 mm wire. CS209A has one oscillator ...