The main aim of the thesis is to produce a metal detector capable of detecting several types of metals at a satisfaying distance, a detector which has the function of detecting the proximity of a metal object and a detector that is not just for demonstration purposes.
From several different detector circuits, I have chosen the one that best fits the target. The correct design of the circuit and the correct selection of components were very important for the operation of the detector circuit. It was also necessary to program the micro-controller properly, otherwise the circuit would not function properly.
After the realization of the selected circuit, optimization of the circuit and the coil was required. Circuit optimization was performed by inspecting the components and selecting them correctly. Coil optimization was done so I tested eight different coils where the shapes, sizes and numbers of coil turns were tested. The tests were conducted using four targets of different metals and shapes (aluminum and iron square target and 1,00 € coin and 0,01 € coin).
Upon completion of the test, a coil of 20 cm diameter and 20 coil turns was selected since the larger coil (30 cm) is not capable of detecting smaller objects well and the smaller coil (10 cm) has a small detection area. After selecting the correct coil, a metal detector housing was also manufactured.