Digital fan tester..

Discussion in 'The Projects Forum' started by thinkerbelle, May 19, 2015.

  1. thinkerbelle

    Thread Starter New Member

    May 19, 2015
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    I am currently working on my final year project:building a digital fan tester system for a Sunon brushless dc fan that will be used without necessary taking the fan out...I plan to incorporate use of LCD & pic microcontroller.
    Kindly advise on how to go about this?and advise on how to program/interface LCD with microcontroller.
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I cannot quite see how you are going to accomplish this when the BLDC controller is embedded in the fan itself.
    There is maybe current and the validity of the fail sense, but what other details else where you hoping to obtain?
    Max.
     
  3. wayneh

    Expert

    Sep 9, 2010
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    Fans move air. If the blades are not damaged, rpm will give a proxy measure of fan performance. But I don't see an rpm meter as much of a final year project.
     
  4. thinkerbelle

    Thread Starter New Member

    May 19, 2015
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    Thanks Max really appreciate your feedback...how would you have rather gone about this?
     
  5. thinkerbelle

    Thread Starter New Member

    May 19, 2015
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    Thanks Max really appreciate your feedback...how would you have rather gone about this?
     
  6. thinkerbelle

    Thread Starter New Member

    May 19, 2015
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    Thank you wayneh,
    Yes it seems like a very easy project for final year :)...but there is a special reason why I am undertaking it.
     
  7. MaxHeadRoom

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    Jul 18, 2013
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    What is it exactly you are attempting to qualify or measure?
    Max.
     
  8. wayneh

    Expert

    Sep 9, 2010
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    What aspects of the fan do you want to test?

    [scooped again by Max!]
     
  9. thinkerbelle

    Thread Starter New Member

    May 19, 2015
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    Basically how to detect whether the fan is running about its correct speed.
     
  10. thinkerbelle

    Thread Starter New Member

    May 19, 2015
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    Basically how to detect whether the fan is running about its correct speed.
     
  11. DickCappels

    Moderator

    Aug 21, 2008
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    Just test for what fans are supposed to do:

    Air pressure in a fixture or flow in CFM (cubic feet per minute) possibly taking temperature into account.
     
  12. wayneh

    Expert

    Sep 9, 2010
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    So a tachometer would give you all you need?
     
  13. MaxHeadRoom

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    Jul 18, 2013
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    You would need to know either what the rated rpm is at the CFM figure for the fan or at least the normal rpm figure, the latter could be done with a retro-reflective tach style sensor to read the rpm.
    Max.
     
  14. thinkerbelle

    Thread Starter New Member

    May 19, 2015
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    Was wondering if I can monitor the square wave coming from the fan by a microcontroller input....then build in the sofware detection loop for this?
     
  15. MaxHeadRoom

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    Jul 18, 2013
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    Where exactly on the fan were you thinking of obtaining the square wave?
    Max.
     
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  16. MaxHeadRoom

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    I see on the Sunon site they give quite detailed performance information for each model, they all appear to have one DC supply via the 2 leads.
    Max.
     
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  17. alfacliff

    Well-Known Member

    Dec 13, 2013
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    if you change to the other type of fan, the one with three leads, the third lead is a temprature sensor, that would give you the most important information, whether the fan was cooling or not.
     
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  18. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    If you are testing a fan that is installed in equipment, you can put a white dot sticker on the hub and use an optical tachometer to determine the speed.
    You can use an acoustic microphone to pickup the frequency of the fan blades against the fan motor struts, and divide that by the number of blades to get the speed.
    You can use an inductive sensor like a coil of wire on a ferrite rod to pickup the switched magnetic fields, and divide that by 2 or 4 to get the speed.
    If this is on a test bench, you can insert a small current shunt resistor in series with the ground lead of the fan, look at the voltage across the resistor, and divide that by 2 or 4 to get the speed.
    You can place a hall effect sensor near the motor hub to sense the magnetic fields, and divide that by 2 or 4 to get the speed.

    ak
     
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  19. wayneh

    Expert

    Sep 9, 2010
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    And if the fan's inlet is plugged, you'll get lots of RPM and zero airflow, like a plugged vacuum cleaner. ;)
     
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  20. MaxHeadRoom

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    Jul 18, 2013
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    Plus lower current!:)
    Max.
     
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