How does Metal Detector Circuit Works? |D.I.Y |Simple Projects at Home

smallseotools.com

Welcome to the Era of Technology. Today, we are going to share how does metal detector circuit works, what are it’s benefits & how you can also make it at home. Keep going. Share your views & how you are going to perform this project in the comment section below.

Metal detector is a very common tool used for checking luggage or bags in shopping malls, hotels, cinema halls, etc. so that it can be ensured that people do not take any metals or illegal/explosive things. It detects the presence of metals. Metal detector circuit is obviously present in all metal detectors but with various purpose.

There are different types of metal detectors like hand held metal detectors(for individuals), walk through metal detectors and ground search metal detectors. Metal detectors can be created easily and the basic metal detector circuit is not that complex.

Here, we present a basic metal detector circuit which can be made easily for domestic purpose like home, gardens, schools, etc.

Breadboard Version of Metal Detector Circuit

Metal Detector Circuit Diagram-

How does Metal Detector Circuit Works? |D.I.Y |Simple Projects at Home 1
This Image was originally Found on ElectronicsHub – Metal Detector Circuit Diagram

Components used in this Metal Detector Circuit –

  • TDA0161 Proximity Detector IC – 1
  • 47nF Capacitors (Ceramic Capacitor code 473) – 2
  • 1 KΩ Resistor (1/4 Watt) – 1
  • 330 Ω Resistor (1/4 Watt) – 1
  • 100 Ω Resistor (1/4 Watt) – 1
  • 5 KΩ Potentiometer – 1
  • 2N2222A (NPN Transistor) – 1
  • 5V Buzzer – 1
  • Coil (Copper wire of 26 – 30 AWG is used to make coil. It is wound in to a coil of diameter 5 – 6 cm & 140 – 150 turns)
  • Additional (for LED)
    • 220 Ω Resistor (1/4 Watt) – 1
    • 5mm LED{Any Color} – 1

Metal Detector Circuit Explained –

  1. When the LC circuit which is L1 and C1, gets any resonance frequency from any metal near it, an electric field will be created. This electric field will induce the current in the coil and changes in the signal flows in coil.
  2. The variable resistor (Potentiometer) is used to change the proximity sensor value equal to the LC circuit. It is better to check the value when the coil is not near the metal. When the metal is detected, the signal in the LC circuit will change. Converted signal is given to proximity detector (TDA 0161), which will detect changes in the signal and react accordingly. The output of the proximity sensor will be of 1mA when no metal is detected and it will be approx. 10mA when the coil is near the metal.
  3. When the output pin is high, the R3 (resistor) will provide positive voltage to Q1(transistor). Q1 will be turned ON and the LED will glow and buzzer will buzz. R2 is used to limit the current flow.

How does Metal Detector Circuit Works –

The LC circuit is the main metal detector part of the circuit. LC Circuit is also termed as Tank circuit or Tuned Circuit. With the help of this LC circuit, TDA0161 IC acts as an oscillator. It oscillates at a particular frequency.

When the LC circuit detects the frequency of any resonance from any metal near it, the electric field will be created which will induce the current in the coil and change the signal flow.

The potentiometer is used to change the proximity sensor value to the LC circuit. It is good to check the value when the coil is not near any metal object. When the metal is detected, the signal in the LC circuit will change.

The varied/changed signal is given to proximity detector (TDA 0161), which will detect changes in the signal and react accordingly. The proximity sensor output will be less than 1mA when no metal is detected. And it will be approximately 10mA (usually more than 8mA) when the coil is near the metal.

When the output pin is high, R3 will provide positive voltage to Q1. Q1 will turn ON and the LED will glow and the buzzer will be activated.

Application of Metal Detector Circuit –

  1. This simple Metal Detector can be used to identify metals like iron, silver, etc. within a specific distance.
  2. Since it is a simple D.I.Y project, we can use this in our home to scan for nails, metal scraps etc.
  3. Apply the creativity & put it over mini beasts to make small robot.
https://www.instagram.com/p/BxPVx_dFEID/?utm_source=ig_web_button_share_sheet

Advantages

  1. The Metal Detector Circuit using a Proximity Detector IC TDA0161 is a very simple and easy to construct metal detector that can be used to detect small metals in our homes, offices and gardens i.e. domestic use.
  2. There is no need for any microcontroller as the Proximity Sensor will be sufficient to run the complete project.

The Only Disadvantage of this Metal Detector Circuit is the detection range. The metal object has to be within a distance of 10mm for the metal detector to detect it.


We welcome all Suggestions -

Leave a Reply

Share via
Copy link