Using Electromagnet to Detect a Steel Door

Discussion in 'General Electronics Chat' started by Michael Campbell, Feb 5, 2016.

  1. Michael Campbell

    Thread Starter Member

    Oct 25, 2015
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    Hi guys,

    I'm using an electromagnet to detect the presence of a steel door through analog pins on an Arduino. This works great if the magnet itself isn't under power, but once I'm running 12 volts through it, the sensitivity of the readings get so small that it's hard to read. I'm using a resistor based voltage divider to bring that signal back in. Is there another way to get a more sensitive reading under power? Perhaps a module that might sit between the EM and Arduino to amplify resolution?
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Why not a reed switch or something like on any home alarm system?
    Or mechanical switch..

    I assume the magnet is just to hold the door open or release it in a fire situation or similar..
     
  3. Michael Campbell

    Thread Starter Member

    Oct 25, 2015
    36
    1
    Actually, I very well could use a mechanical switch, but I'm looking for a solid state solution if possible. The switch is going to get beaten up a bit (high use tool/gadget).
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    There are tons of non-contact sensing solutions.. inductive proximity switches, reed switch, etc...
    They are proven/reliable and can withstand harsh environments,etc....
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
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  6. Michael Campbell

    Thread Starter Member

    Oct 25, 2015
    36
    1
  7. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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  8. Michael Campbell

    Thread Starter Member

    Oct 25, 2015
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    Definitely testing!
     
  9. Michael Campbell

    Thread Starter Member

    Oct 25, 2015
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    quick question, will the inductive proximity sensor be affected by the adjacent ambient electromagnetic field?
     
  10. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Not commonly experienced.
    Max.
     
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