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Will this linear generator (NIB magnet) work to light infrared pulses?

  1. Sep 8, 2009 #1
    Hi. I want to make an assembly in which when one clicks a switch, it lights an infrared LED for 1/30 of a second.
    Basically, instead of having a switch and a battery, i use a linear generator as a switch, giving current only when pressed to light LED. Like any linear generators, when one pushes the switch, the magnet (NIB) part moves along the center of the copper winding coils, creating currents. The whole process last a fraction of a second(just like pressing any mechanical switches).If i use the magnet of this shape (attachment file) with diameter 2cm and length 3cm with copper winding at outer surface of 900 turns(300x3 overlapping turns), and tap the magnet so it moves a short distance quickly through the windings like pressing switches, is there a possibility that it can light infrared LED 1.2 volt for 1/30th of a second? Has anyone ever done something similar? Will increasing thickness of the magnet ring from 1.5mmto 2mm matter significantly?

    Thank you

    Attached Files:

  2. jcsd
  3. Sep 8, 2009 #2
    Is there any particular reason you do not want to use a one-shot (monostable) or a piezoelectric button, like in the Aim n' Flame butane lighters?
  4. Sep 8, 2009 #3


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    You would have to have the coil only affected by one pole of the magnet. So, you would have your magnet outside the coil and being pushed into it.

    If you did it like that, you would certainly get a pulse that you could see on an oscilloscope, but lighting a LED with it might be a different thing. I don't think you would get enough voltage under load, but the only way to be sure is to try it.

    If you are trying to save having to use a battery, the effort might be misguided. You may have to spend a lot of time developing a suitable coil when simple remote controls do the same thing and the batteries last for years.
  5. Sep 10, 2009 #4
    Hoo hoo,

    Some questions you need to answer:

    Is that magnet magnetized radially, diametrically, axially?
    How many turns are in the coil?
    What is the surface gauss (not BrMax gauss) of your magnet (convert to Tesla's)?
    You won't be plugging in NIB into a Faraday equation.
    What is the area of your coil, (in square meters of course)?
    How fast will the magnetic field be moving towards, away from or parallel to the coil (in seconds)?
    What happens if it moves slower or faster (in seconds)?
    What is the resistance of the coil in ohms?
    How does changing any one of; turns, gauss, area of coil, or time affect the output?
    How does wire size affect the area of a coil?
    Pythagoras can help you too. You heard me Pythagoras, get over their !
    How many diodes will it take to turn your Alternating current into Direct Current?
    Last edited: Sep 10, 2009
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