homemade solenoid doesn't work

Discussion in 'The Projects Forum' started by Mutad0r, Feb 15, 2011.

  1. Mutad0r

    Thread Starter New Member

    Apr 6, 2010
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    I got it 10 times in 3 layers.. I tried my most powerful power source, but it did nothing. no magnetic field whatsoever...
     
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    There's probably a field there but a very weak one. How much current are you driving it with?

    How are you sensing the resulting magnetic field?
     
  3. Adjuster

    Well-Known Member

    Dec 26, 2010
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    With an air-cored coil of only 30 turns, you may need quite a lot of current to get a noticeable effect. It looks as if you have used quite thick wire with thick insulation; you might get better results using thinner enamelled wire, as you would be able to fit in many more turns into a given space.

    Thinner wire would need to be supported on a former, that is to say a spool so that the windings will stay neatly in place.
     
  4. wayneh

    Expert

    Sep 9, 2010
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    If current is flowing, you have a field. Trust me, you have not violated the laws of physics. Try using a compass needle near the open end of the coil.

    Your low gauge wire will short most sources - so you may not have as much current as you think. You could wire a bulb in series to limit current and also indicate that current is flowing.
     
  5. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Try discharging e 5,ooo uF cap @ 12V into solenoid.
     
  6. Adjuster

    Well-Known Member

    Dec 26, 2010
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    Discharging 5000μF into such a low impedance could cause quite a bang. I'm not sure that would be completely safe - bear in mind that the OP may not be an adult.
     
  7. wayneh

    Expert

    Sep 9, 2010
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    ...and may not get that opportunity, if he's not more careful. ;)
     
  8. CDRIVE

    Senior Member

    Jul 1, 2008
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    There are times that replies on AAC can be funnier than a face plant on those "Hey, watch this videos"!:D
     
  9. Bernard

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    Aug 7, 2008
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    A Bang; more like a little poof.
     
  10. wayneh

    Expert

    Sep 9, 2010
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    Hah! That's what SHE said!
     
  11. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    The imductance of that inductor will be very low, around 150-300 uH, but with high current handling ability. Guessing on dimensions for that value.

    Can't think right off of an application for it though.
     
  12. SgtWookie

    Expert

    Jul 17, 2007
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    I'm betting more like 5uH to 15uH, as there is no core.

    Saturation would occur quite rapidly.

    If you ever opened up a manufactured solenoid or relay, you would find LOTS of turns of very fine enameled magnet wire on the coil.
     
  13. Bernard

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    Last edited: Feb 17, 2011
  14. Ron H

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    Apr 14, 2005
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    I don't think it's possible to saturate an air core coil.
     
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