Questions tagged [piezo]

Piezoelectricity is the electric charge that accumulates in certain solid materials (such as crystals, certain ceramics, and biological matter such as bone, DNA and various proteins) in response to applied mechanical stress.

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31
votes
1answer
65k views

Active vs Passive Buzzer

I recently borrowed an Arduino Inland Basic Starter Kit. It includes an active and passive buzzer. What is the difference? I can hear a difference in sound when I use the ...
8
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3answers
2k views

Does a pickup microphone work in space (vacuum)?

Of course in space there is no sound transmitted via air, so there is no air-borne sound, but there is structure borne sound. This sound can be recorded with a pickup microphone, but do pickup ...
7
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0answers
95 views

A peculiar issue in an atomic force microscope [closed]

I'm not sure where else to turn for this issue. Hopefully you all can offer some insight. Sorry the title is so vague, I don't know how to explain this concisely. I am a teaching assistant for an ...
6
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3answers
550 views

Piezo transducer preamp and AGC/compressor

I've been suggested this circuit as a good low-noise high gain piezoelectric transducer preamp (used to pick up really faint sounds in water). It is nice because it includes a high pass filter (yet ...
6
votes
1answer
156 views

GaN & SiC piezoelectricity problematic?

I read that galium nitride and silicon carbide are piezo materials.Does this cause some problems? I can imagine that unwanted piezoelectricity directly in the circuit path would cause some kind of ...
5
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2answers
598 views

Sensor to detect ball impact

I want to detect the impact of a ball against a table tennis racket. I'm currently using Piezo discs tightly fixed in the racket wood. However, in addition to correctly detect impact, the sensor ...
5
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2answers
1k views

Unwanted noise/oscillations on op amp output

I am working on a piezo vibration voltage amplifier circuit. The working schematic is attached below. From a 9V battery I am using a 7805 to provide 5V to both my single supply op amp and the 5V power ...
5
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2answers
1k views

Measuring the resonance point of a piezo ultrasonic transducer

I assume it will be something along the lines of feeding it a sine wave via a resistor and measuring the signal across the resistor as the frequency changes. Does this sound viable? Also, on resonance ...
5
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3answers
3k views

How to detect very hard impacts with piezo?

Normally I'm a software guy, but I've recently decided to try my hand at some electronics projects. What I want to do is make my own impact sensor for target shooting. What I'm picturing is a piece of ...
5
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0answers
298 views

Convert analog piezo “transition” to digital signal

I'm trying to get what amounts to a knock indication into a microcontroller input from a piezo sensor. It's looking fairly good now at the fifth iteration, and about ready to provide digital levels ...
4
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2answers
1k views

How can I reduce the volume of my dryer buzzer?

Like many of us, the buzzer in my dryer is loud as hell. I recently opened up my dryer to repair it and easily found the buzzer and simply disconnected it. However I got to thinking: Could I replace ...
4
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1answer
2k views

Using a piezo disc as an input and output device to ATtiny85

I am working on an art installation and plan to use a number of these small circuits to make sounds, to sense sound/vibration and also to move the device (using a triangle wave output). This link ...
4
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1answer
2k views

Understanding an ultrasonic piezo driver circuit

[Disclaimer: I'm okay-ish with digital electronics, but somewhat a noob with analog stuff. Since this circuit is a) pretty simple and b) still covers both areas, I was hoping that somebody here could ...
4
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1answer
2k views

Electronic stethoscope / contact mic not quite working

I built a circuit similar to this one here and I can hear my breathing but not my heartbeat. Now I used this piezo from digi, and I used a FDV301n fet instead of their JFET. Eventually I removed the ...
3
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3answers
3k views

MOSFET source measures 12V, still nothing will turn on

Please, bear with me, I'm a real rookie at electrical engineering. So please be easy on me. ;-) I've got the following circuit. I have a 5 seconds HIGH / LOW interval on ...
3
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4answers
15k views

How to determine the polarity of a piezoelectric buzzer?

Inside of a piezo buzzer is a little unimorph/bimorph disk which converts voltage to mechanical movement. To function as a buzzer, you just feed it an ac signal at its resonant frequency. However, ...
3
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2answers
764 views

Help me understand this high voltage amplifier circuit for driving a piezo actuator

I am researching HV driver amplifiers for controlling piezoactuators. My background is in physics, so I am a bit out of my comfort zone here. I came across the following schematic and have been ...
3
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1answer
312 views

Unwanted noise in oscilloscope display

Hi I'm a beginner on using an oscilloscope and I'm sorry if my question may be repeated in other posts. I was working on a circuit with the following materials: (1) an Al plate (5mm thick) (2) a ...
3
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1answer
4k views

This guitar piezo opamp buffer lacks any sort of bass, why?

My preamp in my acoustic guitar died after I put the battery in backwards. I need to replace it, and fast. Piezos have incredibly high output impedance (5+ mohm) so a buffer circuit is used to knock ...
3
votes
1answer
676 views

What is the pressure/force sensor used in the Beddit?

The Beddit sleep-tracking device (Beddit and @indiegogo) has a pressure sensor that looks like a thin (~0.3mm?), flexible tape about 2ft long. The tape seems to be constructed of several layers ...
3
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1answer
115 views

Appropriate model of an unknown sonar piezo

I have a collection of piezoelectric transducers that I have got from old devices. No print stamp on them, and I couldn't get a schematic of the device that could help me to find a datasheet. I ...
3
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2answers
465 views

Protecting circuit from piezoelectric disc voltage spike

I have a piezoelectric disc, and I'm trying to use to build a primitive sonar. I connected the disc to an oscilloscope and if I press very hard on the disc, I see that the voltage can spike pretty ...
3
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1answer
255 views

Determining speed of turbocharger via sound?

There are inductive sensors which can be retrofitted to turbochargers to measure their speed, like this: Examples can be seen here. Installation requires some careful and precise drilling and ...
3
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3answers
758 views

Ultrasonic Piezo passive component matching

I am attempting to drive a 640kHz piezo electric transducer with an FPGA. For some reason, I cannot get a matched signal, and do not know why. I've captured a scope readout where CH1 is IN, CH2 is A, ...
3
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2answers
277 views

ECG signal amplification

I am developing a project for ECG detection using PVDF (Piezo Film) sensor. I have already managed to detect my heart rate but since the sensor used produces voltage corresponding to vibrations, ...
2
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3answers
2k views

How to make a piezoelectric transducer buzz louder?

I am trying to make a piezoelectric transducer buzz loudly, but have so far only been able to make it create a quiet hum. I have tried using a basic amplification circuit with an NPN, but this made ...
2
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2answers
271 views

Single supply OPA445?

So basically I'm trying to make a circuit for a piezo-electric actuator. I only have access to a single supply at +70V for my op amp, an OPA445AP. Vin varies between 0 and +3V. I've looked at the help ...
2
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1answer
308 views

How to amplify a signal for piezo transducer from 1 Vpp to 200 Vpp at 400 kHz and 500 pF load

I'm a researcher working with phased ultrasonic transducer arrays. I need to amplify a sine wave at 400 kHz and 1 Vpp to 200 Vpp. It has a capacitive load of 500 pF. I'm little ...
2
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2answers
804 views

Finding the Resonance Frequency of a Piezo

Using the circuit outlined in this white paper I have been able to find the anti-resonance of the piezo in question. I am using a Rigol DG1022 to create my signal, a sine wave at 20 V p-p, and a ...
2
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2answers
931 views

Driving a 600W Piezo transducer for sonar application

I am looking to build a circuit capable of driving a 600W piezoceramic transducer with an impedance of 200Ω at a frequency of 50kHz. Since it is being used in a sonar application only short pulses(...
2
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1answer
2k views

Amplifying a Piezo with an Op-Amp

I am trying to use a piezo as a speaker. (I know that a piezo has a bad frequency-response. However, In my application it is better to use one instead of a speaker, since normal speakers don't like ...
2
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1answer
92 views

Does the type of preamplifier used for a piezoelectric sensor change its physical resonant frequency?

Two common amplifier circuits used for piezoelectric sensors are voltage amplifiers and charge amplifiers (pictured respectively). With the charge amplifier, the sensor is shorted but this is not the ...
2
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1answer
59 views

Where can I find ultrasound machine regulations?

Diagnostic ultrasound machines are limited in their output power so that the sound waves don't cavity the microbubbles in the body. What I want to know is how do manufacturers prove their power ...
2
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1answer
1k views

Ultrasonic generator - a couple of questions

Here is the ultrasonic generator circuit I'm trying to understand: It is powered by USB and it produces 100V at 100kHz on the piezoelectric speaker BQ1. Two ...
2
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1answer
3k views

Using an unamplified piezo in a mic-in jack

it's my first time working with piezos and I'd like to use one as an input to my iPhone via the microphone port to allow my app to detect vibrations. in order to do this, I was thinking that I'd use ...
2
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1answer
1k views

Is this circuit for driving a piezo buzzer correct?

I'm designing a board which will feature a small SMD piezo buzzer which will be used for generating tones of varying frequencies from a PWM signal. I'm looking for a simple circuit which will be safe ...
2
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2answers
159 views

Thin plate piezoelectric transducer glued to flat surface in shear mode

I want to glue a piezo plate looking like in the image below such that the wide surface of the plate gets glued onto a flat surface. The image is part of the datasheet from here. If I apply an AC ...
2
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1answer
1k views

piezo sensors's resonant impedance

I'd like to know what does the term "piezo resonance impedance" mean. It is commonly available with the datasheets of piezo sensors such as this. Is it the same as the piezo transducer's insulation ...
2
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2answers
168 views

Erroneous results from ADC and piezo disk

Okay, so I posted this question before but my design has changed and has become unmanageable. I am attempting to create an electric tuner device which uses a piezo disk to accurately measure the ...
2
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1answer
69 views

How to draw ~1A from Li batteries without damaging/over-stressing them?

I have designed a micropump driver powered by 2x AA (Li) batteries, the pump is piezoelectric and requires 27V. The pump requires a switching waveform, at the battery side this draws (including ...
2
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1answer
238 views

Filtering noisy buffer output

Please bear with me as this is my first time working with filters. I am trying to scale down the voltage from my piezo to a voltage which my ADC can read (from >100V on the piezo to 0-5V on the ADC ...
2
votes
2answers
189 views

Using piezoelectronic components as position trackers

I've been trying for a while to get this circuit working, I looked all over the place and now, defeteated, I come to the point where I need to ask for help with my specific case. My plan was to use ...
2
votes
1answer
171 views

Explain this schematic

I am taking apart this non-invasive blood pressure monitor to see how it works. The engineer decided to use (what looks like a piezo-electric element to measure the relative pressure from the cuff, ...
2
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2answers
1k views

If I drive a piezo sensor with switched DC, will I get back over-voltage?

I have a built a vibration detection circuit based on an op-amp to trigger high speed photography of balloons popping. (I'm using this circuit) (From this blog - not my image) It works well. It ...
2
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2answers
4k views

How to improve the sensitivity of a piezo assembly?

First and foremost I’d like to warn you that I’m not a native English speaker. Sorry in advance for my mistakes. And also I’m kinda a newbie in terms of electronics; so go easy on me please, I will ...
2
votes
1answer
957 views

Amplified 80dBA 40KHz Sound From 3V Square Wave?

How can a loud high-frequency tone be produced from a 3V square wave? Given that: the square wave is 3V and can have a varying frequency (max 4mA) 12VDC high-current supply is available ...
2
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0answers
99 views

CW Doppler probe for fetal doppler and blood flow velocity

I am currently working on a microcontroller based project to measure the blood flow velocity using ultrasound doppler. I have purchased two Spengler 8 MHz continuous mode probes in order to measure ...
2
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0answers
45 views

Turning on a latch circuit with a piezo sensor?

I am trying to build a relatively 'simple' circuit with a piezo sensor that turns on an LED for ~10-20 seconds after it has been tapped. In the off-state the circuit should use zero current to ...
2
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0answers
636 views

Crystal Oscillator Design and “Crystal Drive Level”

I followed the video at the link http://www.analogzoo.com/2015/07/ . The video directs watchers to a tool at http://www.analogzoo.com/lab/pierce_bjt.html to help determine parameters to cause ...
1
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2answers
659 views

How to filter out in-band noise at the same level as my signal?

I'm implementing a system wherein I'm detecting waves as they come trough my piezoelectric sensors in a board. Essentially, I would want to record the time these signals appeared in my sensors as I ...

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