[Dzl] as well as his rather severe looking kid are metal detector enthusiasts. however when they couldn’t discover their store-bought metal detector earlier this summertime they just went ahead as well as developed their own. [Dzl] starts his compose up with an explanation of exactly how a lot of oscillator based metal detectors work. this differs by utilizing an Arduino to checked out from the metal detecting coil.
The circuit starts with an oscillator that creates a signal of about 160 kHz which is regularly determined by the Arduino. When metal enters the coil it alters the frequency, which is instantly chosen up the Arduino. instead of that characteristic rising tone this rig utilizes a Piezo buzzer, issuing the type of clicks you’d usually partner with a Geiger counter.
The last part of the develop was to discover the very best coil orientation. They settled on thirty turns around a metal bucket. An old Ikea lamp is the best type aspect to hold their hardware which seems to work like a charm.