Rotation Switch

Discussion in 'General Electronics Chat' started by Ringleader, Jul 29, 2009.

  1. Ringleader

    Thread Starter New Member

    Jul 29, 2009
    Hello everyone,

    I was wondering if there is such a switch as the one shown below.


    When the wheel spins it triggers the switch on for a certain period of the wheel's rotation and then it is off for the rest of the rotation. It is important that the switch only activates because of the rotation and not the time of rotation, and also that there is no contact between the wheel and the activation site of the switch. I looked around for something like this, but I cant find a cheap one that works exactly as the diagram shows. So if you know where I could get one, that not only works well but is cheap, that would be very helpful towards my project.
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Place a magnet on the wheel and use a reed switch. What kind of voltage and current?
  3. Aklem

    Active Member

    Jun 18, 2009
    use a ir slot sensor and put a bar in the way of the slot, the length of the bar determens the duration of the on period.
  4. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    What are the mechanical characteristics of the "wheel". Are we looking at an engine flywheel turning 3000 RPM, or something turning only once a day? What's the length of the "ON" arc? Some options may not work with high speeds or long arc lengths...or inhospitable environments.