Loading

Simple Metal Detector Circuit

admin May 25, 2010 3 Comments

Circuit Description

The circuit diagram of cost effective metal detector has been published here. This circuit and an old pocket radio constitute a simple metal detector device. This circuit is a Colpits oscillator circuit is operating at medium frequency band. The radio and the circuit are placed close to each other. Radio is tuned to the same frequency of the circuit. At this condition there will be no sound from radio since their frequencies are matched and cancel each other. This is the final arrangement of metal detector.

If a metal object is placed near this circuit, the inductance of the coil changes. By the effect of this, frequency of oscillation of oscillator changes and a mismatch in frequency occurs between the circuit and radio. This change inductance is utilized here to detect metals. When mismatch occurs, radio produces hissing sound and metal is detected.

Circuit Diagram

Simple Metal Detector Circuit

Simple Metal Detector Circuit

Notes

  • To make L1 make 60 turns of 36SWG enameled Copper wire on a 1 cm PVC tube.
  • Powering the circuit using an adapter rather than a battery induces noise. It is better to use battery for powering radio projects since it reduces noise.
  • Radio for metal detector can be an old pocket radio.
Comments
  • August 4, 2010

    Simple Metal Detector Circuit…

    Circuit Description The circuit diagram of cost effective metal detector has been published here. This circuit and an old pocket radio constitute a simple…

  • Majs
    March 24, 2011

    At school, with pupils making very simple but working metal detector

    http://majstin.narod.ru/

  • May 25, 2011

    Lol, I don’t understand a word you just said. But I’m sure it is ‘simple’ for the high tech guys.

Leave a Reply

Your email address will not be published. Required fields are marked *