zero cross REFERENCE

Discussion in 'The Projects Forum' started by Dimpi, Dec 28, 2013.

  1. Dimpi

    Thread Starter Member

    Sep 6, 2013
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    0
    helo all,

    can anyone give me some idea of how to make a circuit which would provide ZERO CROSS REFERENCE to the input of microcontroller ?the 'zero cross reference' circuit to be made receives input through rf commands...suggest me with cost effective ideas..

    any help,any theory would be highly appreciated.

    thanx in advance.
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,009
    3,233
    What is "ZERO CROSS REFERENCE"? :confused:
     
  3. inwo

    Well-Known Member

    Nov 7, 2013
    2,433
    315
    The most common way that I know is lines connected to input of optic isolator.

    Those types are not deemed safe (here) and get thread closed.

    Here is a transformer type from google.
     
  4. Dimpi

    Thread Starter Member

    Sep 6, 2013
    96
    0
    can we use some ic having inbuilt comparator and zener diodes ....or some kind of optocoupler for zero crossing??i am very new to this domain ,needs help.
     
  5. t06afre

    AAC Fanatic!

    May 11, 2009
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    Is this somehow connected to your motor control thread
     
  6. Dimpi

    Thread Starter Member

    Sep 6, 2013
    96
    0
    yes sir...its connected...
    but this is the circuit i am making so that micro sets zero crossing as reference at its input..so that when delay is set up in software section...the delay is generated at the output of micro keeping zero crossing as voltage reference...
    so the delayed pulse will provide different firing angle to the triac and this wy way we can control the speed of fan..

    sir can u help me with any ideas of how to make simple and efficient circuit for zero cross refernce at the input of micro??
     
  7. t06afre

    AAC Fanatic!

    May 11, 2009
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    Here is a search for you https://www.google.com/search?q=zero+cross+detector+microcontroller Even if you plan to use another controller than used in the app notes. You can still pick up some ideas on how it is done. It is important that you use some sort of isolation between your controller board and the high voltage part of your circuit. Using a Optocoupler with Phototriac Output is a excellent way to go
     
  8. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,542
    2,369
    Fairchild AN-3006.
    Max.
     
  9. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Is "to be made receives input through rf commands" truly a requirement? If so, I got nuthin'.

    If not, the transformer type suggested by inwo works well. For most micros, those having ESD diode protection on the input you will use, the circuit can be simplified:


    [​IMG]
     
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