Metal detector based on Colpitts oscillator

U okviru završnog rada obrađena je tema detektora metala temeljenog na Colpittsovom oscilatoru. Opisan je princip detekcije vodljivih objekata te je dan pregled različitih izvedbi uređaja za detekciju vodljivih objekata s posebnim naglaskom na BFO detektorima, tj. detektorima s oscilatorom frekvencije otkucaja. Uz to, opisan je postupak projektiranja i izrade zavojnica potrebnih za realizaciju jednog takvog oscilatora, dok je simulacijom u programu Multisim utvrđena funkcionalnost načelne sheme BFO detektora. Nakon toga je u okviru rada i izrađen jednostavni detektor metala korišten za demonstraciju detekcije vodljivih objekata, temeljen na Colpittsovom oscilatoru kao osnovom za BFO. Konačno su navedene neke dodatne mogućnosti kojima bi se navedeni detektor mogao unaprijediti.In this work, the topic of a metal detector based on a Colpitts oscillator is discussed. The principle of detection of conductive objects is described and an overview of different designs of devices for detection of conductive objects is given, with special emphasis on BFO (beat frequency oscillator) detectors. In addition, the process of designing and manufacturing the coils required for the realization of such oscillator is described, while the simulation in the Multisim program determines the functionality of the basic scheme of the BFO detector. Furthermore, a simple metal detector was made and used to demonstrate the detection of conductive objects, based on the Colpitts oscillator as the basis for BFO. Finally, some additional features that could improve the detector are listed