Description.
This is a simple single chip metal detector circuit based on IC CS209A from the Cherry Semiconductors. A 100uH coil is used to sense the presence of metal. The IC CS209A has a built in oscillator circuit and the coil L1 forms a part of its external LC circuit which determines the frequency of oscillation. The inductance of the coil change in the presence of metals and the resultant change in oscillation is demodulated to create an alarm. The LED gives a visual indication too. This circuit can sense metals up to a distance of few inches.

Circuit diagram with Parts list.

single-chip-metal-detector-circuit


Notes.

  • Assemble the circuit on a general purpose PCB.
  • The switch S1 can be a slide type ON/OFF switch.
  • The IC must be mounted on a holder.
  • The POT R1 can be used to adjust the sensitivity of the circuit.
Author

42 Comments

  1. sakthicel

    CN I use this type sensor to detect a train for my project…… I want to know the technical specification of it…… Pls reply me….

  2. nganga stephen

    thank fod the assisrance in electronics circuitrg

  3. what kind of ic can be used insted of ic cs209a.

    • Seetharaman

      No other IC can be used. It is a custom IC for the application.

  4. can i use a 120uH inductor instead? 100uH is not available in markets here

    • Seetharaman

      You can try. but as per IC manufacturers’ recommendation you have to use 44AWG litz wire on siemens former.
      L: Core: Siemens B65531-D-R-33
      52 Turns, 6×44 AWG, Litz Unserved Single Polyurethane

  5. hi can this circuit be modified so that its range can be increased
    Plz reply
    thank you

    • Seetharaman

      If the diameter of the search coil is increased It have more sensitivity. Try by winding 8 to 12 inch dia coil of 100uH.
      recommended by manufacturerL: Core: Siemens B65531-D-R-33 52 Turns, 6×44 AWG, Litz Unserved Single Polyurethane.

  6. how much is the distance that the circit find metal (in meters)?
    can we use it as a vehicle presence sensor?

  7. hi I am in search of a type of metal detector which can detect iron in 30cm distance.
    in fact I can modify your circuit for this distance.

  8. all of comments are just questions, is there any body to answer???

  9. cheap shamballa beads

    Hello, I just wanted to mention, I disagree. Your post doesn’t make any sense.

  10. Jaisin jacob

    Sir,CS209A is not available in our region.Is any IC instead of this.
    Plz reply.

  11. ABDALLAH

    looking forward to get electronic circuit projects

  12. Hi…
    What is the maximum range of this circuit?
    I mean the maximum distance it can detect the metal.
    How much turns should i have in the searching coil?

  13. seetharaman

    Hi Prateek as per IC manufacturers’ recommendation you have to use 44AWG litz wire on siemens former.
    L: Core: Siemens B65531-D-R-33
    52 Turns, 6×44 AWG, Litz Unserved Single Polyurethane
    refer
    http://md4u.ru/ppoint/CS209.pdf

  14. hii sir
    actually i want to know that , is it possible to detect every element by a detector ( any detector) means ,Can anything be detected ????
    like IC cs209a , which can detect metal easily .

  15. Prateek Birthare

    how to wind or make L1 inductor.
    Plz reply

    Thanks in advance

  16. i need more explanation on the circuit and the functions each component in the circuit

  17. seetharaman

    Hi Wajahat refer the datasheet. you have to wind on siemens torroid with litz wire.
    L: Core: Siemens B65531-D-R-33
    52 Turns, 6×44 AWG, Litz Unserved
    Single Polyurethane
    http://md4u.ru/ppoint/CS209.pdf

  18. i saw the metal detector project on ur website. how to wind or make L1 inductor.plz reply

  19. dear sir,
    my cricket ball gets lost when il b playing cricket. so is there any circuit that can detect the ball. please send the circuit if it is available {simple circuit}.

    thankyou
    from kiran

  20. Usulogbo Beauty Erumena

    Please i need a detail explanation on this circuit and the function of each component in the circuit.Can anything be done to this circuit to get 50watt alarm system?

  21. Usulogbo Beauty Erumena

    Please,can u elaborate on the working of this circuit and the function of each component in the circuit? I need it for my school project.

  22. can u please elaborate the working of this circuit?
    can this circuit be made on a bread board?

  23. SIR,

    I AM AN ENGINEERING ASPIRANT FROM SOUTH INDIA,CAN YOU PLEASE HELP ME WITH SOME REPLACEMENT IN THIS IC CS-209A,WHICH IS NOT AVAILABLE IN OUR REGION.

    MY MAIL ID IS [ myfaithnka@gmail.com ]

    THANKS IN ADVANCE.

  24. nelson theophilus

    please, i need more explanation on the circuit and the functions each component in the circuit

  25. sheka leonard

    I like the circuit so I need more detail

  26. ananthnag

    the CS209A chip is no longer available…

  27. jose morales

    hi,i sale from colombia “the DORADO”,a PIC microcontroller programmed how metal detector on a chip…VERY EASY METAL DETECTOR CIRCUIT WITH LCD!!!

  28. give me d detalils on metal detetor.
    i need this on my college project
    plz waiting….

    i need working and current flow on this metal detector circuit