Let us design Simple Metal Detector using 555 Timer Circuit. A metal detector is a device which has the ability to detect metal or a piece of magnet. Its just like hunting a treasure for knowing secret by pirates but its not easy. Nowadays you can find metal detector has so many applications like in Airport, Offices, Shopping malls, security work for detecting suspicious damage causing bomb or metallic weapons.
In this projects we are going to make a simple metal detector using IC 555 Timer. The project is very cheap as the cost is just 1 dollar approximately.
Metal Detector using 555 Timer Circuit
The circuit diagram is very simple as it has very less components and can be assembled easily. The requirements for metal detector circuit are:
1. 555 Timer IC 2. Speaker – 8 ohm 3. Electrolytic Capacitor (2.2 uF, 2.2 uF and 10 uF) 4. Resistor (50K) 5. Inductor or coil (10 mH) 6. 9 volt Battery
Working of the Circuit
The working mechanism is based on the frequency of oscillation of RL circuit. When a magnet or metal is brought near to the inductor the output frequency of oscillation changes and output comes in the form of sound from the speaker.