A metal detector can be used at airports, in theatres, or elsewhere. It is used to detect someone holding a metal (arms, etc.) to protect citizens. We will develop a basic metal detector circuit in this project. There are so many metal detector projects, but most of them are in the design complex so we will make a basic 555 Timer IC metal detector circuit. This circuit is easy to make and requires a few basic components.
We must understand the idea of inductor and RLC circuits before going forward. Let us address the inductors first. Inductors are nothing but enamel coils in different shapes and sizes of copper wire. The inductance of an inductor is measured according to different parameters. We are primarily interested in the inductor center in all these criteria since the induction value varies significantly depending on the center.
Hardware Component
The following components are required to make Metal Detector Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | IC | NE555 Timer | 1 |
| 2. | Capacitor | 2.2µF | 2 |
| 3. | Speaker | 8Ω | 1 |
| 4. | Variable Resistor | 47K | 1 |
| 5. | Supply voltage | 9V | 1 |
| 6. | Coil | 170 Turns of 10 cm diameter | 1 |
NE555 IC Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer
Metal Detector Circuit
Working Explanation
In this section, we will discuss the operation of this project. The 555 IC Timer serves as a generator for a square wave and produces pulses of human-audible frequencies. The capacitor should not be changed from pin2 to pin1, as audible frequencies should be produced.
This is a circuit RLC consisting of a 47 K resistance, a 2.2 μF capacitor, and an inductor of 150 turns. It is the metal detecting component of this RLC circuit. Today, as previously stated, there is a high induction value for the metal core inductor over an air core.
Applications and Uses
The metal detector is very common in shopping centers, restaurants, movie halls, and other locations to track people’s baggage or luggage, to guarantee that people should not wear metals or unlawfully explosives.
