Water drop detect sensor?

Discussion in 'General Electronics Chat' started by mpcotuong, Jun 15, 2011.

  1. mpcotuong

    Thread Starter Member

    Aug 26, 2010
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    Hi All,

    I had tried couple sensors but none of them are detect water drop. The water drop like you drop the water down from the cup and need the sensor detect it to give output high. Please let me know, if you have any idea how to detect water drop in front of the sensor. The sensor need to detect within 10 inches.

    Thanks,

    Kevin
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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  3. cjdelphi

    New Member

    Mar 26, 2009
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    why an infrared led why not any near infrared such as an optical mouse?.. I don't get that part, is it something to do with displacement with the shorter wavelength? I should look up how optical mice work.... i guess.

    Can a microphone be used with some kind of pass filter to detect a noise of a certain type?.....
     
  4. mpcotuong

    Thread Starter Member

    Aug 26, 2010
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    Hi Beenthere,

    I did not get it work yet. Do you have other solution?

    Thanks,
    Kevin
     
  5. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Sure. Try using doppler radar.

    You're welcome!
     
  6. cjdelphi

    New Member

    Mar 26, 2009
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    The water would absorb the sound waves including doppler?

    How about ultrasonic? send out and listen and if it stops sounding water is blocking/absorbing the energy, invert the signal to get a high out....
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
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    I have used an IRLED and phototransistor successfully detecting water drops falling at over 130 KPH.

    You have not posted a schematic of your attempt.
     
  8. mpcotuong

    Thread Starter Member

    Aug 26, 2010
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    Hi Beenthere,

    Can you post your schematic which one you said it working?

    Thanks,

    Kevin
     
  9. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    And since you want to detect a water drop up to 10 inches away, maybe a photo of how you implemented the circuit.

    Ken
     
  10. mpcotuong

    Thread Starter Member

    Aug 26, 2010
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    Hi Kemoffet,

    I don't have the circuit yet. I need to ask you guys, if know any circuit to make it detect water drop with 10 inches from the sensor and detect it

    Thanks,

    Kevin
     
  11. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    How about giving us a simple hand drawn sketch of water drop set-up.
    Is this a drop of water or 4 lb of water?
     
  12. mpcotuong

    Thread Starter Member

    Aug 26, 2010
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    Hi Bernard,

    It 's just drop the water from the cup cross the sensor for detect it and give output high.

    Thanks,
    Kevin
     
  13. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Will the drops always fall along the same vertical line? What are the ambient light conditions?

    Ken
     
  14. mpcotuong

    Thread Starter Member

    Aug 26, 2010
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    Hi KMoffett,

    Yes the water drop alway vertical line. It 's same thing you just drop down the water from your cup.

    Thanks,
    Kevin
     
  15. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Define " the cup ".
    How high is the cup above the sensor?
    How is the drop rate controlled?
    If drop is straight down with no deviations,a laser pointer's beam should be narrow enough to be deflected or blocked by a drop.
     
  16. mpcotuong

    Thread Starter Member

    Aug 26, 2010
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    Hi Bernard,

    The cup drop water down to bottom about 20 inches. The sensor is placing in middle of 10 inches. When the water drop cross the sensor, it need to detect the water drop and give output high.

    Thanks,
    Kevin
     
  17. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Maybe I'm confused when you referred to a distance of 10", I assumed you meant that the sensor was up to 10" from the drop stream. Or, is the 10" from the cup just another spec'. How close to the stream could a beam-break sensor be?

    Ken
     
  18. beenthere

    Retired Moderator

    Apr 20, 2004
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    Perhaps the OP just needs a circuit. The pix are of the raindrop detector and the significant circuitry that could detect drops falling from 90' up. The stuff got done for the Agronomy Department back in 1984, so more modern op amps and phototransistors could be substituted.

    The IRLED's had about 40 ma through them.
     
  19. mpcotuong

    Thread Starter Member

    Aug 26, 2010
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    Hi KMoffett,

    Sorry my question was not clear. I mean the sensor will detect in area of 10 inches. It mean you move the cup far away within 10 inches from Sensor and drop the water down from 20 inches top to the floor. The Sensor can mount from floor up to 5 inches.

    Thanks,
    kevin
     
  20. mpcotuong

    Thread Starter Member

    Aug 26, 2010
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    Hi Beenthere,

    Thanks, for send me the circuit. How about the sensor part. I am not clear the left pic.

    Kevin
     
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