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How does it work?

  1. Mar 16, 2010 #1
    Hello Experts,

    I bought a top that has LEDs blinking when you spin it. It does not light up when not spun.

    This is the top I am referring to :

    I opened the top and see a small circuit that is powered by 3 button cells.
    I tried to find out how it turns on the circuit. I realise only when i spin the top will the circuit be energised.

    I thought the spinning mechanism contains a coil or magnet. I used a magnet to check if there is magnetism and found none is present.

    If i shake the top with my hand, it does no light up.
    Only if it is spun will it work.
    The harder it is spun, the more electricity seems to go through the circuit as the 3rd blue LED only lights up when spun at higher speed.

    I wonder how does it work? Could you advice what could be the mechanism?

    Last edited by a moderator: Sep 25, 2014
  2. jcsd
  3. Mar 16, 2010 #2


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    Staff: Mentor

    Probably just centrifugal force and spring-loaded contacts.
  4. Mar 16, 2010 #3


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    Science Advisor

    It may have centrifugal switches to turn on the power as the toy rotates . Power could come from the batteries.
    These are just a weight that swings outwards when there is rotation and, when it does this, it turns on a switch.
    Last edited: Mar 17, 2010
  5. Mar 18, 2010 #4
    Thank you for enlightening vk6kr0 and russ watters!
    Yes, i hear rattling sound when the top is shaken by hand. I suppose those are the switches.

    Have a great day!

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