Contact less tachometer

Discussion in 'The Projects Forum' started by Afeesh, Feb 17, 2011.

  1. Afeesh

    Thread Starter New Member

    Jun 12, 2009
    9
    0
    Hi to all,


    I am doing a project contact less tachometer.The circuit is from the following link http://www.ikalogic.com/d_tach.php.But when i tested with the sensor module circuit I found that the IR diode is affected by the environment light.This is the first issue i faced. The second one i find is that the ir signal reflects from all the surface.I want a particular point from the disc to get ir reflection.for that what may be the material i should use.

    thanks in advance
    Afeesh
     
  2. debe

    Well-Known Member

    Sep 21, 2010
    947
    184
    What i did was colour part of the surface to be checked with black paint to give a good contrast difference. The machine i use uses apulsed Ir transmitter @ 20Khz to stop the ambient light from affecting it. This was a kit i built back in 1988 as an optical pickup tacho. Its still going & could be used upto 25000RPM for checking model aero engine RPM.
     
    Last edited: Feb 17, 2011
  3. Afeesh

    Thread Starter New Member

    Jun 12, 2009
    9
    0
    what is the receiver module u you use.if you share the circuit diagram it will more useful.

    Thanks
    Afeesh
     
  4. debe

    Well-Known Member

    Sep 21, 2010
    947
    184
    Here is the Tacho & article. I built this for checking shaft & Diesel engine RPM.
     
    Last edited: Feb 17, 2011
  5. debe

    Well-Known Member

    Sep 21, 2010
    947
    184
    Rest of article. Couldnt get your link to work.
     
    Last edited: Feb 17, 2011
  6. Adjuster

    Well-Known Member

    Dec 26, 2010
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