How to amplify voltage signal resulted by piezoelectric?

In summary, the conversation discusses how to amplify a voltage signal produced by a piezoelectric material. The participants suggest using a transistor or op-amp circuit and a high impedance amplifier. They also mention considering the application and frequency of the signal. The conversation ends with a suggestion to connect the piezo material to a Wheatstone bridge and use an operational amplifier to obtain a higher voltage output.
  • #1
bauketek
3
0
Hi,
I am not very good at electronic circuit,,
I just want to ask:
How to amplify voltage signal resulted by piezoelectric?
Since the voltage resulted by this material is very small,,
thank you for any help
 
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  • #2
bauketek said:
Hi,
I am not very good at electronic circuit,,
I just want to ask:
How to amplify voltage signal resulted by piezoelectric?
Since the voltage resulted by this material is very small,,
thank you for any help

Welcome to the PF.

We need more information in order to help you. What piezo sensor are you using? What are you sensing? Can you post a link to the datasheet for this sensor?

You would normally use a transistor and/or opamp circuit to do the signal amplification. What is the context of your question? What is the application? Is this for school, work, or hobby?
 
  • #3
thank you for replying,,
Actually, I am an undergraduate student majoring in physics,,
I have a project with my professor which is making the piezoelectric materials (so we make them, not buy them).
But, I have problems in measuring the voltage,,
since I don't have the datasheet, therefore,
what should I find first in order to make an appropriate amplifier?
Is there any method to do that?

Thank you
 
  • #4
Your professor should be able to give you a clue (or even your notes!?) about the voltage you could expect. It would not be good to embark on a circuit design before considering what amplification / frequency response / noise performance you would need. It could be a trivial thing or a very complicated measurement.
 
  • #5
In the piezoelectric effect mechanical effort is converted to voltage.

This voltage can be very high (as in spark generators 1) or it can be more modest (as in vibration transducers 2).

Whatever the current that the piezo material can supply is very small indeed.

This is another way of saying that the voltage output of the piezo sample has to be fed into an electronic device with a very very high input impedance. This usually requires special circuitry.

Berkeman is correct in asking about the circumstances of the measurement.

Are you trying to obtain impulsive voltage on a scope or are you looking for a continuous voltage output or what?
How are you making electrical connection to the material to observe this output voltage?
 
  • #6
You will need a very high impedance to detect the voltage. Probably the easiest way do that is with an opamp that uses mos-fets in the front end. This is the data sheet for one. http://www.intersil.com/data/fn/fn957.pdf
 
  • #7
Can you oscillate the piezo? You will usually need some kind of "charge amplifier" (look it up). But these only work well when the signal changes with time.
 
  • #8
You need an amplifier with a high impedance. If you want some quick answers, search for i instrumentation amplifiers.

Something like this: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=296-15093-5-ND
should do the job. You'll want to put this in-line with a basic op-amp follower circuit before reading it's output.
 
  • #9
KingNothing said:
You need an amplifier with a high impedance. If you want some quick answers, search for i instrumentation amplifiers.

Something like this: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=296-15093-5-ND
should do the job. You'll want to put this in-line with a basic op-amp follower circuit before reading it's output.

i think that'll be OK without buffering the output. might want to order several up front to account for the typical experimenter errors, though.

of course, the thing he doesn't mention is frequency, which might become problematic if too much gain is required.
 
  • #10
hey it's nothin much complicated just connect your change in resistance of the piezo material to the wheatstone bridge i.e make it one of the resistances and by varying the other resistance values note down the current. This small voltage produced is given to the operational amplifier so we get the voltage of higher values
 
Last edited by a moderator:
  • #11
This thread is 2yrs old, the OP has not been active in 6mos.

Locked.
 

What is piezoelectricity and how does it generate a voltage signal?

Piezoelectricity is the ability of certain materials, such as crystals and ceramics, to generate an electric charge in response to applied mechanical stress. This is due to the rearrangement of positive and negative charges within the material, resulting in a voltage signal.

What are some common methods for amplifying a piezoelectric voltage signal?

Some common methods for amplifying a piezoelectric voltage signal include using an operational amplifier, a transformer, or a charge amplifier. These methods involve increasing the voltage level while minimizing noise and interference.

What factors should be considered when selecting an amplifier for a piezoelectric voltage signal?

The main factors to consider when selecting an amplifier for a piezoelectric voltage signal are the amplification gain, bandwidth, noise level, and power supply requirements. It is important to choose an amplifier that is capable of providing the necessary amplification without introducing additional noise.

Can the voltage signal generated by a piezoelectric material be amplified to any desired level?

No, the voltage signal generated by a piezoelectric material is limited by the material's physical properties and the amount of stress applied to it. It is important to carefully select the appropriate amplification level to avoid damaging the material or introducing excessive noise.

Are there any additional considerations when amplifying a piezoelectric voltage signal for use in a specific application?

Yes, the specific application in which the voltage signal will be used may require additional considerations, such as the need for specialized filtering or shielding to reduce interference. It is important to carefully evaluate the requirements of the application and select the appropriate amplification and signal conditioning methods.

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