Help with fan and datasheet (speed control)

Discussion in 'General Electronics Chat' started by Little Ghostman, Jan 1, 2014.

  1. Little Ghostman

    Thread Starter Member

    Jan 1, 2014
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    Hi I have a fan, model number FFC0612DE, the datasheet is here
    http://www1.futureelectronics.com/doc/DELTA PRODUCTS CORPORATION/FFC0612DE-F00.pdf

    for one of my projects I need to control the speed via PWM, I tried a pwm signal direct to the read lead (VDD input) and I managed to get control, the best frequency was around 1.3KH.
    Then I decided to look at the datasheet as the fan has 4 wires, what has me confused is the difference between the yellow and the blue wire.
    Blue wire is described as Frequency
    and yellow described as control PWM.
    I am assuming I send a pwm signal down the yellow wire, but what is the blue wire for?
    Thank you for any help
    LG

    PS please go easy on me I am only 13, but keen to learn
     
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    This fan has two modes of speed control. You, the user/designer, choose which one of the two to use.

    You only need to choose one. If you can do PWM, then I suggest using it because it appears to be easier to use and understand.

    Speed control using frequency is described on page 6 of the pdf. Speed control using PWM is described on page 7 of the pdf.
     
  3. Little Ghostman

    Thread Starter Member

    Jan 1, 2014
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    Ah I see now, thank you very much. One more question if I may, it talks of frequency for PWM and says it can take a frequency from
    ~30-300K HZ, is the start frequency 30 HZ or 30KHZ I think its 30 HZ but not sure sorry
     
  4. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    The way I read it, you have a choice of frequencies for PWM signal. The minimum frequency is 30 Hz. The maximum is 300 kHz.

    You said earlier that you already used 1.3 kHz. This frequency is in the range of 30 Hz to 300 kHz. That is why it worked.

    The notes on PWM says that preferred frequency is 20 kHz. If you can, I would suggest using it.
     
  5. Little Ghostman

    Thread Starter Member

    Jan 1, 2014
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    When i used pwm before on it i used the red lead, it will be micro controlled with software pwm so 20KHZ should be ok, When i tried over 11KHZ before the fan acted up and wouldnt run correctly, but then again i wasnt using it correctly hence the datasheet
    Question, Really nice fans actually. I got them cheap :D
     
  6. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    The red lead is for power. When you used pwm on it you in effect simply turned the fan on and off, but you did it fast enough that it looked like you were applying some dc voltage.

    If I am reading datasheet right, as long as your pwm signal on the red wire was seen as 7 to 13 volts, the fan was ON. And since the pwm wire (yellow) was not connected, the fan automatically went to maximum speed (page 7).

    So with PWM on red lead, you either have:
    * fan OFF (pwm is seen as less than 7 volts dc)
    * fan ON and speed set to maximum
     
  7. Little Ghostman

    Thread Starter Member

    Jan 1, 2014
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    I have tried it with the PWM wire and t works a treat! Very powerful little fan! the back of it is open and I caught my finger on the blades at full speed :D, I now have 2 stitches in it :D, talk about stupid!
     
    Austin Clark likes this.
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