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Anyone tried using the Weatherproof Trasnducer? — Parallax Forums

Anyone tried using the Weatherproof Trasnducer?

PublisonPublison Posts: 12,366
edited 2012-10-21 05:53 in General Discussion
Have not seen any chatter on this device since it came out.

https://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/502-14000/List/0/SortField/4/ProductID/755/Default.aspx

Has anyone tried it?

Phil must have gotten a sample. :)

Jim

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-10-19 12:48
    This is the first I've known about it. 'Not sure what the intended audience for it is.

    'Looked at the datasheet, which includes a sample schematic. The schematic includes a pulse transformer, which might scare a few potential designers -- needlessly, I might add -- but inductive components tend to do that for some reason. :)

    -Phil
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-10-19 12:58
    I have a couple of these transducers. My idea (likely a bad one) was to just switch them for a pair of normal ultrasound transducers on a cheap SR-04 sensor.

    Time for Phil and others to tell me what a bad idea this is. I'm sort of joking, but I am very glad when someone on the forum straightens me out and saves me a lot of time from pursuing hopeless projects (like using different frequencies to drive an ultrasound sensor).
  • PublisonPublison Posts: 12,366
    edited 2012-10-19 13:07
    The reason I'm askin' is it's been out since 5//2011 and I don't see anyone using them yet.

    http://forums.parallax.com/showthread.php?113182-Waterproof-ultrasonic-sensor/page2&highlight=waterproof
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-10-19 13:21
    I think they were going to be part of a weather proof Ping which was discontinued before it ever went into production.

    The transducers have been mentioned a couple of times on the forum but I don't know of anyone who as used one.
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-10-19 15:14
    I had thought they were similar to the rear bumper transducers used in cars with "backup collision warning systems". I had looke at them when people had asked about waterproof pinging but (not surprisingly) had no idea how to make them work.
  • PublisonPublison Posts: 12,366
    edited 2012-10-19 15:35
    Time for Parallax to update the product page with a driver circuit! :)

    The Data Sheet is not too helpful. Maybe they can turn some of these if people knew how to use them.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-10-19 16:10
    Publison wrote: »
    Time for Parallax to update the product page with a driver circuit! :)

    The Data Sheet is not too helpful. Maybe they can turn some of these if people knew how to use them.

    Maybe an accurate circuit would scare us all off. By not knowing how hard they are to use, us gullible types might buy them thinking it shouldn't be too hard to make a weather proof ultrasound sensor. (BTW this should be seen in the "just joking font".)
  • electromanjelectromanj Posts: 270
    edited 2012-10-19 16:23
    I would be interested if someone has used these also. I ordered a few a while back and forgot about them until I saw this thread. Didn't really have a plan for them at the time, but I like to have things on for those rainy or snowy days.

    traVis
  • PublisonPublison Posts: 12,366
    edited 2012-10-19 16:39
    Duane Degn wrote: »
    Maybe an accurate circuit would scare us all off. By not knowing how hard they are to use, us gullible types might buy them thinking it shouldn't be too hard to make a weather proof ultrasound sensor. (BTW this should be seen in the "just joking font".)

    I bet Ken or Jessica will send an email to Phil, "how much will it cost us to get a working circuit? Where still trying to get WiFi going" :)

    Just kiddn'
  • CircuitsoftCircuitsoft Posts: 1,166
    edited 2012-10-19 17:31
    I recall comments about the waterproof ping sensor being unreliable, and that they were never able to get the to work well enough to be comfortable selling the entire product. I imagine they're a bit less sensitive than the open ones, and harder to use for that reason.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-10-19 23:35
    Wow! This looks like it might be good for underwater ultra-sonics. You could create an ROV that sees the bottom and other objects.

    But, darn it = = = > It says "Do not use it in liquid."
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-10-20 00:04
    Loopy Byteloose wrote: »
    Wow! This looks like it might be good for underwater ultra-sonics. You could create an ROV that sees the bottom and other objects.

    But, darn it = = = > It says "Do not use it in liquid."

    I think it was Phil (or maybe Mike Green) who pointed out the ultrasound wouldn't pass through the water well. You're better off using some sort of water proof speaker (or better yet an underwater fish-finder type transducer).
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-10-20 00:52
    The acoustic impedance of water is far different than that of air. Transducers designed for one medium will be a poor match for the other.

    -Phil
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-10-20 09:45
    I suppose these are intended for automotive use where you want to determine how close the curb is or if there is something in back of you.

    Maybe a sensor to keep pigeons off your window sill by activating a robotic scarecrow.

    Now that I know that ultrasound is too high frequency for sonar, I can get on with something that might work. I suppose I should get an audio sample of the ping from a submarine in a movie and use that as a starting point.
  • JLockeJLocke Posts: 354
    edited 2012-10-20 11:33
    About the only place you'll get an audio sample of a ping from a submarine is in the movies. Submarines don't like to use active sonar; it tends to give away your position. I was a surface sonarman in the U.S. Navy (got out in 1980) and even the surface fleet was starting to transition to passive towed-array sonar. But... the system I worked on (AN/SQS-26BX) could blast 160,000 watts of power into the water at a center frequency of 3.55 kHz. Lower frequencies give longer ranges, but less resolution.
  • Tracy AllenTracy Allen Posts: 6,664
    edited 2012-10-20 12:20
    PVDF film has a much better acoustic impedance match to water. Superb application notes at meas-spec.

    Prowave has a wide and readily available (Element 14, Farnell) line of ultrasonics. Their downloads url has a great catalog with nice data sheets. Also app notes.

    Here for example are graphs of the sensitivity and sound pressure level for a 20mm open transceiver vs the same for a 25mm closed transciever.

    Screen shot 2012-10-20 at 12.09.21 PM.png
    Screen shot 2012-10-20 at 12.08.41 PM.png
    Screen shot 2012-10-20 at 12.09.21 PM.png
    447 x 308 - 32K
    Screen shot 2012-10-20 at 12.08.41 PM.png
    443 x 263 - 33K
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-10-20 12:21
    Loopy Byteloose wrote:
    Now that I know that ultrasound is too high frequency for sonar, ...
    It's not the frequency. Some sonars operate upwards of 200 kHz. It's the interface with the medium that's different for transducers meant for air and those meant for water.

    -Phil
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-10-20 18:32
    Go to Sea World and drop a hydrophone in the Dolphin pool. Ask permission first. You should get some sonar their.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-10-21 04:04
    I guess I need to build or buy myself a boat first for this project or settle for finding a rubber ducky in the bath tub.

    So it is the impedance, not the frequency that is the problem with generating and monitoring sound underwater. The senors all seem rather expensive to buy separate from the packaged technology.

    Of course, a towed array means that one might rent or borrow a boat.

    But getting back to these weatherproof transducers....
    Does anyone see a good application for them? Maybe a trigger for a pre-recorded audio tape loop on a ice cream truck. When people approach, a message would either change or play.
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-10-21 05:53
    Loopy Byteloose wrote: »
    Of course, a towed array means that one might rent or borrow a boat.

    ...and lots and lots and lots of wire!! :0)
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