Transformer solder pins?

Discussion in 'The Projects Forum' started by electronice123, Jun 28, 2014.

  1. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
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    I recently made my own coil bobbin on a lathe using a plastic rod.
    At the ends of the bobbin I drilled small holes to fish the wire through.

    My problem is that the wire is 34 AWG so it's very fragile. I have had to completely unwind and rewind the coil once already because the wire broke right at the hole. What can I do to solve this problem?

    I was thinking of getting some really small screws, threading them into the bobbin ends and then soldering the wires to the screws?

    Does anyone have any suggestions or recommendations?

    [​IMG]
    Thanks in advance
     
  2. JohnInTX

    Moderator

    Jun 26, 2012
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    That would work assuming the plastic could take the heat of solder. The screws in turn could secure solder tabs on both sides - one side for the coil wires, the other for connections.

    You could try chamfering the holes to break the sharp edges.
     
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  3. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
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    Those are some great ideas that I never thought of. I did have the exact problem you mentioned before. Tried soldering to the screws but then melted the plastic.

    What could I use as solder tabs?
     
  4. JohnInTX

    Moderator

    Jun 26, 2012
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  5. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
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    Awesome, thanks for the tip. That is just what I need.
     
  6. MaxHeadRoom

    Expert

    Jul 18, 2013
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    2,373
    If you turned the bobbin and presumably you intend another version, as it is a bit late to tap the holes on the wound one, I would also suggest using the lockwasher terminals in the link, when going this small I would look at a metric screw, the thread is finer than the standard US machine screw, and when you have the empty bobbin tapped, place a screw in with one lockwasher and turn the screw down flush with the bobbin wall, then when you use two lockwashers for the coil and terminal conductor, there should be no danger of damaging the coil.;)
    Max.
     
  7. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    302
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    Thanks Maxheadroom,

    Any bobbin I make in the future will have a widened area on each end for the connections. I'll also try the metric screws with the lockwashers like you said.
     
  8. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Of course if you are in the US it could be a slight problem.;)
    Max.
     
  9. Sensacell

    Well-Known Member

    Jun 19, 2012
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    When making electromagnet coils like this, I solder the fine solid wire ends to lengths of insulated stranded #22 wire, insulate the solder joint with some polyester or kapton tape, (very thin and strong) then bury the splices in more wraps of tape.

    The idea is to immobilize and protect the delicate junction and provide a robust wire to exit the coil.
     
  10. Metalmann

    Active Member

    Dec 8, 2012
    700
    223
    You can try soldering the tiny wires to the anchor pins first, then attach.....(Epoxy, or threaded screws into the hole, last).
     
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