please for any eng know ???

Discussion in 'General Electronics Chat' started by u-a-l, Jun 14, 2010.

  1. u-a-l

    Thread Starter New Member

    Jun 12, 2010
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    for retched :
    thanks 4 u now i have steps to start my project ....
    in my frist time :rolleyes: i suggest bulit digital multimeter by auto rang but i do not find circuit to do that work :( then i change my mined to use manual rang but i find not big proplem that :confused: about the value of resistors it's so small .
    after all that i write my comment about this proplem (small resistors) but if you know circuit for auto range please share it with me
    about programming pic i have programme that can used to display the voltage which comes from circuit working by (manual rang ) at the end i decide to make max rang 300v

    for potato
    i now that there are many multimeter is cost a view dollars but i must bulit some one like any normal multimeter because it's my final project in last year in learning and i hope to make a some different multimeter that can measure many thing like (voltage & current & resistors & cap & power factor & display the harmonic ,temp,humidity , ferquncey, testing (doide , thyrister ,.....) by summarize i hope to make a multimeter doing any measuring needed eng student
    about my supervisor he do not understand any thing about measuring :confused: that make me confused :(
    but with you i hope find solution soon ;)


     
    Last edited by a moderator: Jun 14, 2010
  2. bertus

    Administrator

    Apr 5, 2008
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  3. u-a-l

    Thread Starter New Member

    Jun 12, 2010
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    what happened engs no one answer me ?????????????
     
  4. retched

    AAC Fanatic!

    Dec 5, 2009
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    It has been a long day. Someone will get to you. There are MANY things going on.

    Before you start into your project, some research is needed.

    First, find all the information you can on testing:
    (voltage & current & resistors & cap & power factor & display the harmonic ,temp,humidity , ferquncey, testing (doide , thyrister ,.....)

    Once you know the proper way of testing these things, you can incorporate them into your design.

    Bertus gave you a good link in post #2. You can get MANY good ideas and alot of information at that link.

    You need to read the datasheet for your PIC and decide if you will use an onboard ADC or a seperate IC for the ADC.

    As SgtWookie said before, you may want to use a multimeter IC for your measurements.

    You can pass the measurements to the PIC for display or any math needed to compute things like power factor and frequency/duty cycle and such.
     
  5. u-a-l

    Thread Starter New Member

    Jun 12, 2010
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    that's Wright i have been search before bout all the books ii speak about not modern ways that's use in measurement like Dc moving-coil mete r, Dc Galvanometer, Ac Moving-Coil Voltmeters ,Electrostatic Voltmeters. and this doesn’t work with pic
    and the only circuit i find it suitable with pic is (many resistors connecting in series with one small resistor connect in parallel , the voltage which i have measure it between tow[small resistor] point using op-amp ) that way is manual scale
    last comment from u you speak about auto rang i hope if you have idea share it with me
    Mr.retched
    i find some circuit but who i connect it with pic ?????????????
    this is one of them
     
  6. u-a-l

    Thread Starter New Member

    Jun 12, 2010
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    i don't now how i download this circuit in my comment
    if u now tell me please
     
  7. retched

    AAC Fanatic!

    Dec 5, 2009
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  8. retched

    AAC Fanatic!

    Dec 5, 2009
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    To add an attachment to your comment, click on the 'Go Advanced' Button next to 'Post Quick Reply'

    After you click 'Go Advanced' You can scroll down until you see 'Manage Attachments'

    Click on 'Manage Attachments' to upload your file to your reply.
     
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