#PIEZO DISC ELEMENTS PROJECTS HOW TO#

I am not at all concerned of noises that may cause a false alarm. Also, it will be connected to a processor that is able to do fourier transform and other forms of DSP, so I can easily distinguish between external noise / interference and water flowing. In other words, sounds not loud enough to vibrate the piping. The piezo is immune to sound passing through air.

I know for sure that there will be interference. It will be used for something else at a manufacturing plant. I am not going to use this project at home. PD: I have a problem with this project: if water has laminar flow/low turbulence through that pipe, there will be very little vibration/noise to pick, if any at all.Ī Venturi would be way more sensitive to even small and smooth flows. ĥ) in any case, post results, they may help others with similar needs, even if to avoid wasting time. To determine whether the project is feasible or not:Ģ) wire a shielded wire to a high impedance preamp, 1M is good, 10M may be better if sound you need to detect is very low frequency.ģ) scope the output, see whether you can visually determine whether there is water flowing through pipe or not you will also see background noise, even if you do not use an acoustic pickup such as an electret, the kind of high SPL ambient noise you mention will vibrate/shake the pipe and that will also be picked by the piezo.Ĥ) if there is a reasonable signal to noise ratio, say water flow vibration is at least 3 or 4 times higher than 'sneaked in' ambient noise, then you can process that signal and do something useful if signal to noise works against you, there's not much you can do. And ambient sound or vibration from passing trucks would have no effect on them.Ĭlick to ue, it will also pick all noises picked up by that solid object ĭigikey has lots of vibration sensors: Vibration Sensors | Sensors, Transducers | DigiKeyĪnd just to offer up an alternative, does the pipe change temperature when whatever is flowing through it? There are many inexpensive solid state temperature sensors that could be used easily if so. You might be able to use it or take its idea and adapt your own. I have seen the same piezo discs in all of those. SO you probably do not need to worry whether the piezos you find are for buzzers or speakers or microphones or drum pads. But put sound to it or vibration, and it generates a voltage. Put a voltage to it and it changes shape, a varying voltage then will make sound. The drum pads on electronic drum kits use piezo discs on a circle of wood. Piezos are also used as microphone, that is what is inside a cheap 'crystal microphone'. Piezos are also used as tweeters, the very common Motorola piezo now made by CTS are real cheap, and I have taken them apart to steal the piezo disc in the past. Will a Piezo with a higher or lower dB sound emission rating be better at picking up audio (remember it is now being used as a MIC, not a buzzer)?

I assume a larger diameter Piezo disc is better.

#PIEZO DISC ELEMENTS PROJECTS HOW TO#

I do know how to build the project, I just need to know what specifications to look for in the Piezo to make it the most suitable contact MIC as selecting the right Piezo for the job will make the project more accurate and easier to program. I would like to use the Piezo as a MIC and thus seek advice from people out there with more expertise than myself, that have done this before, to advise me on what kind of Piezo would be best suited for the application I would like to use it for. So a Piezo (when used as a buzzer) is selected based on Internal or External drive circuitry as well as the tone (determined by the frequency it emits). Piezo discs are mostly used for buzzers, which emits sound. Click to expand.I did see this project, but I do not want to know how to do it, I am seeking advice on how to select a Piezo, something which is not just as simple as using ' '.

Piezo disc elements projects