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Piezo Film Vibra Tab Mass — Parallax Forums

Piezo Film Vibra Tab Mass

CenlasoftCenlasoft Posts: 265
edited 2008-04-01 18:06 in General Discussion
Hi,
I just ordered and received some Piezo Film Vibra Tab Mass sensors from Parallax. Are there more application circuits anywhere other than what's on this site? I tried the sensors site, but it is hard to find anything.
I want to make a circuit that measures vibration from a train that passes every three hours next to my apartment. Maybe a seismograph?
Thanks,
Curtis

Comments

  • FranklinFranklin Posts: 4,747
    edited 2008-03-23 03:24
    I don't think this is the right sensor for your application. This device will tell you if there is a vibration but not how much.

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    - Stephen
  • LeonLeon Posts: 7,620
    edited 2008-03-23 18:54
    Why not use an accelerometer, or a Geophone?

    Leon

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    Amateur radio callsign: G1HSM
    Suzuki SV1000S motorcycle
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2008-03-28 17:56
    I think it may work fine. While it is a tiny sensor, you can merely add a paperclip to the end of it to increase the mass and response. Conversely, you can restrain the lower end to reduce the sensitivity. You just have to mount it to a stable base [noparse][[/noparse]like a brick] so that you don't get false triggers.

    It is certainly worth a try.

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    PLEASE CONSIDER the following:

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    ···················· Tropically,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • CenlasoftCenlasoft Posts: 265
    edited 2008-03-28 20:04
    Hi,
    I want to thank those who responded. Does any one have a thought on a circuit to read the output other than the switch type? The literature stated that this sensor could produce up to 70 v. I will play with testing that statement this weekend.
    Thanks,
    Curtis
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2008-03-29 09:11
    Well, if you want to read the full 70 volt range of the device, you have to probably use a voltage divider to get it down to a reasonable processing level. Then you might use an op amp to capture the peak pulse and and ADC to create a digital numerical input into your microprocessor for data logging or whatever purpose you want.

    Otherwise, a protective clamping of the peak with a 5.1 volt zener diode of appropriate power rating could clip the top of the spike and keep your microprocessor from being harmed.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    PLEASE CONSIDER the following:

    Do you want a quickly operational black box solution or the knowledge included therein?······
    ···················· Tropically,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-04-01 18:06
    It would be possible with an Op-Amp and an ADC to measure very slight vibrations. You would need to experiment with the output of the Op-Amp to find the desired range and possibly to clamp the output past 5V using a 5.1 Zener Diode. In tests I was able to measure my breath from the sensor using a scope. Take care.

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    Chris Savage
    Parallax Tech Support
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