“If properly adjusted according to the instructions, it is able to detect a small coin at a distance of 15 cm
In this project I will present you a Very Simple “Beat Frequency Oscillator” type of Metal Detector. BFO metal detectors are relatively simple and inexpensive compared to other types of metal detectors. It is one of the simplest and most common types of metal detectors.
The principle of operation is as follows:
When a metallic object is in close proximity to the search coil, the beat frequency produced will be different compared to when there is no metal present. This change in the beat frequency indicates the presence of a metal object and allows the user to identify and locate it.The metal detector described in this project is taken from the chemelec website with minor modifications, and is extremely simple to build, containing only three transistors. However, despite its simplicity, it gives excellent results. If properly adjusted according to the instructions, it is able to detect a small coin at a distance of 15 cm, and a large metal object at a distance of 50 cm and more.”