Watch demagnetiser.

Discussion in 'General Electronics Chat' started by Len33, May 13, 2015.

  1. Len33

    Thread Starter New Member

    May 13, 2015
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    Hi!
    Does anyone have (Or know of) a proven circuit for a 'Ringing Choke' or 'Resonant Coil Demagnetiser' for use with demagnetising watches?
    Thanks.
    Len33
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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  3. alfacliff

    Well-Known Member

    Dec 13, 2013
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    have you got an old transformer type soldering gun? the wellers have quite a magnetic field. just push the trigger with the watch against the housing, and pull the watch back away before letting go of the trigger.
     
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    an example of a shaded pole motor with rotor removed.
    [​IMG]
     
  5. DickCappels

    Moderator

    Aug 21, 2008
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    I don't have a ready design but I can tell you that you would need to have a high Q inductor and a good quality high voltage capacitor. The capacitor is charged up then dumped across the inductor, causing a damped sine wave current oscillation through the coil. Getting a high enough Q so you do note leave more residual magnetism than you want while leaving a way for the flux to exit the inductor, go through the object being demagnetized and back into the inductor at the same time can be challenging. A digital or storage scope with a current probe would be a useful tool.
     
  6. joeyd999

    AAC Fanatic!

    Jun 6, 2011
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    I don't know what you mean by "watch demagnetiser", but in the old days, we used to use these for erasing magnetic media.
     
  7. MikeML

    AAC Fanatic!

    Oct 2, 2009
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