PIC16f877A & CAR HORN(EMI) problem

Discussion in 'The Projects Forum' started by delta088, Sep 16, 2012.

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  1. delta088

    Thread Starter New Member

    Sep 13, 2012
    :) Respected members I need some suggestion about my PIC16f877a microcontroleer based project.I have built a CAR alarming system using pic16f877a MICROCONTROLLER and it's work fine but whenever i blow the CARHORN microcontroller malfunction (PIC circuit and car horn connected same 12v dc car powersupply battery) and it's trigger false alerming.After some experiment I realise that carhorn create huge EMI and pic microcontroller is too much EMI sensitive.I have try almost all kind of noise reduction processes like parallel capasitor etc..but all of them fail.only if connect a high value & volt capasitor in the CAR HORN then it's working but it's not a good way to solve this problem.so somebody pls give some suggestion for this problem or suggest me a microcontroller whis is not EMI/NOISE sensetive...

    My progect is almost ready but I can't fullfil my drem for this problem A BIG HELP is truely need for me..

    Thank you..
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    Post a schematic of your PIC board. I want to see your power supply. Where did you tap your car's power? Where did you ground the PIC circuit to the car frame?
  3. SgtWookie


    Jul 17, 2007
    This Board doesn't support automotive modification topics, as per the Terms of Service, paragraph 6.

    Since your home-made alarm is installed in an automobile, we cannot help you with it.

    You might try over at Electro-Tech Online.
  4. #12


    Nov 30, 2010
    I disagree. Filtering the electrical noise at the place that is causing it is a proper thing to do.

    Now, go to http://www.electro-tech-online.com/ where they do this kind of work.
  5. bertus


    Apr 5, 2008

    I am closing this thread as it violates AAC policy and/or safety issues.

    6. Restricted topics. The following topics are regularly raised however are considered “off-topic” at all times and will results in Your thread being closed without question:

    • Any kind of over-unity devices and systems
    • Automotive modifications
    • Devices designed to electrocute or shock another person
    • LEDs to mains
    • Phone jammers
    • Rail guns and high-energy projectile devices
    • Transformer-less power supplies
    This comes from our Tos:
    Terms of Service
    There will be enough sites where automotive questions can be discussed :
    Member selected automotive forums

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