Understanding Principle of Metal Detector Circuit

If you’ve just received a new metal detector, you’re probably wondering what’s the principle of metal detector circuits.
A metal detector circuit is an electronic circuit that detects the presence of metal nearby, so today we’re going to show you how to understand it.

  • A metal detector circuit works by identifying metals and changes the output signal accordingly.
  • The principle is based on the fact that metals have magnetic properties.

Metal Detector Circuit:

  1. The circuit basically uses two coils, one at 90 degrees to the antenna coil, and the other in series.
  2. The antenna coil broadcasts an electromagnetic field, and the ferrous metal objects obstruct the field, causing a change in the electromagnetic field which acts on the secondary coil.
    The antenna coil broadcasts an electromagnetic field, and the ferrous metal objects obstruct the field, causing a change in the electromagnetic field which acts on the secondary coil.
  3. The secondary coil produces an output, which is proportionate to the object’s mass.

Disconnect the Battery

  1. If the battery is connected to the circuit, disconnect it.
  2. Remove All Components
  3. Remove every component from the circuit.
  4. Check for Continuity
  5. Check continuity between each wire and positive and negative terminals.
  6. Connect the Battery to the Circuit
    Connect the Battery to the Circuit
  7. Reconnect the battery to the circuit and check for any improvements.

Change Mode

  1. You need to make sure that the mode you’re using in the metal detector circuit is the one you want.
  2. When you set the mode to All Metal, it’s possible that small metal objects like coins and small change pieces will be detected.
    When you set the mode to All Metal, it's possible that small metal objects like coins and small change pieces will be detected.
  3. So, try setting the mode to Iron only.

Change Tone

  1. This looks for a change in impedance.
  2. Change in Current
    This uses current to indicate whether a metal object is present.
  3. Change in Voltage
    This uses voltages proportional to the amount of metal object present.

Change Sound Setting

  1. Click on Start
  2. Type Sound in the search field
  3. Click on Sound
    Click on Sound
  4. Under Playback section, click on Playback device
  5. Under Sound tab, click on Properties
  6. Under Hardware tab, click on Device usage
  7. Under Sound playback, select Exclusive mode
    Under Sound playback, select Exclusive mode
  8. Turn off the device
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