Design of a Beat Frequency Oscillator Metal Detector

Abstract

This paper discusses the design,construction,and simulation of a beat frequency oscillator metal detector. Over the years, it has become an important issue to limit, the entry of people into certain places with weapons or instruments of harm and destruction.in this paper is a design of an effective means of detecting dangerous weapons made of metal in order to reduce crime rate in the society. It uses the principle of electromagnetic induction and adopts a digital beat frequency technique. The system uses a search coil to detect metallic objects at a close range and gives a visual, auditory and vibratory indication once the metallic object is detected. The search coil forms part of an LC oscillation circuit. The activation frequency of the LC oscillator is primarily determined by the value of involved inductor and capacitor. In case an inductance is altered, the frequency does not remain the same by changing its value through the introduction of a metallic object.