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  1. #1
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    interruptual

    i am looking for someone who has a tried and working circuit for a zero crossing detector which can be interfaced to a pic

    •   Alt17th April 2006, 15:09

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  2. #2
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    zero crossing detector circuit

    hi..
    you can use an OPAMP 741 for zero cross detector.


    1 members found this post helpful.

    •   Alt17th April 2006, 15:16

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  3. #3
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    Re: zero crossing detector circuit

    this is the circuit of zero cross detection with a pic port.



    •   Alt17th April 2006, 18:53

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  4. #4
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    Re: zero crossing detector circuit

    Here are some other examples of zero crossing detectors ..

    Regards,
    IanP



  5. #5
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    zero crossing detector circuit

    Hi,

    Have a look at microchip application note AN958.
    www.microchip.com
    Good luck.



  6. #6
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    Re: zero crossing detector circuit

    It is easy man, think about this... each leg of microcontroller has two protection diodes (zener), if the applied volatge is over 5 volt, let us say 220 Vrms, then the zener will cut it to 5 volt, and if it is -220Vrms, then the another zener will work in forward and make the volatge almost zero.

    What you need is high impedence resistor (100Mohm) connected from the source (220Vrm) directly to the PIC interrupt leg, or you can use non-interruptual method just by scanning that pin if the frequency is not very haigh.

    You need some protection and noise remover circuits.

    *** It is hazardous but will cost you nothing!!

    Good luck

    Hani



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