The problem with piezoelectric and contact mics is that they are not well matched to typical audio inputs. The reason why these devices often sound tinny is because the piezo sensor presents its signal through a series capacitance which is small, typically 15nF or less. When wired to a normal 50 kilohm line input this forms a 200Hz high-pass filter, which eliminates the bass. Because the piezo disc has a very high impedance (1 MΩ typical), it should be buffered to avoid possible impedance mismatch with an existing audio system. This circuit acts as a impedance buffer, and some amplification does not hurt as long as it is around 40dB.
The large disc doubles as a speaker and microphone. The small oscillator is for creating the radio signal in the smoke detector chip, that has no datasheet online.
Hi, also useful: using the disc to detune a GPS ceramic antenna (1.575 GHz) so it works in the hydrogen band. It needs a bit of tweaking and having a unit with the right characteristics but as long as its the same material you have a fighting chance. Best to remove the front coating not the back as its typically in worse shape, same with GPS ceramic. Possible to simply glue them together with a powder ceramic coating like BaTiO3 EL dielectric material in Epoxy.
Yeah, ditto on the solderng tip.... don't apply much heat at all and make the connection as fast as possible. I used to work for a sub-contractor for the US DoD and once had to solder about 2000 of these little buggers. I think we had to scrap about 40 of them because of that little issue.
One might attach it to his/her instruments for "electric" fiddle or banjo or othersuch. Nearly all "accoustic" guitars come with piezo "pickups" already install these days. Gives different tone tones than magnetic pickups normally found on amplified guitars. No I've not done it yet, just found out my new source of piezos. Normally located near the bridge, move it around for best tones.
The problem with piezoelectric and contact mics is that they are not well matched to typical audio inputs. The reason why these devices often sound tinny is because the piezo sensor presents its signal through a series capacitance which is small, typically 15nF or less. When wired to a normal 50 kilohm line input this forms a 200Hz high-pass filter, which eliminates the bass. Because the piezo disc has a very high impedance (1 MΩ typical), it should be buffered to avoid possible impedance mismatch with an existing audio system. This circuit acts as a impedance buffer, and some amplification does not hurt as long as it is around 40dB.
I've taken apart headphones for repair, so I know there's a piezoelectric speaker, and that doesn't have the usual paper cone, their just a small disk with wires soldered to it.
Hi! - Do you know where I can buy lots of those Piezo with a feed back tongue? I want to make simple tuneable buzzers with a transistor, resistor and capacitor, to make a simple tuned pipe organ. Is there a special name for this type of Piezo disc? John N
The problem with piezoelectric and contact mics is that they are not well matched to typical audio inputs. The reason why these devices often sound tinny is because the piezo sensor presents its signal through a series capacitance which is small, typically 15nF or less. When wired to a normal 50 kilohm line input this forms a 200Hz high-pass filter, which eliminates the bass. Because the piezo disc has a very high impedance (1 MΩ typical), it should be buffered to avoid possible impedance mismatch with an existing audio system. This circuit acts as a impedance buffer, and some amplification does not hurt as long as it is around 40dB.
The large disc doubles as a speaker and microphone. The small oscillator is for creating the radio signal in the smoke detector chip, that has no datasheet online.
Hi, also useful: using the disc to detune a GPS ceramic antenna (1.575 GHz) so it works in the hydrogen band. It needs a bit of tweaking and having a unit with the right characteristics but as long as its the same material you have a fighting chance. Best to remove the front coating not the back as its typically in worse shape, same with GPS ceramic. Possible to simply glue them together with a powder ceramic coating like BaTiO3 EL dielectric material in Epoxy.
Yeah, ditto on the solderng tip.... don't apply much heat at all and make the connection as fast as possible. I used to work for a sub-contractor for the US DoD and once had to solder about 2000 of these little buggers. I think we had to scrap about 40 of them because of that little issue.
You can take it and add a cone to it. to make a speaker for a crystal radio.
One might attach it to his/her instruments for "electric" fiddle or banjo or othersuch. Nearly all "accoustic" guitars come with piezo "pickups" already install these days. Gives different tone tones than magnetic pickups normally found on amplified guitars. No I've not done it yet, just found out my new source of piezos. Normally located near the bridge, move it around for best tones.
The problem with piezoelectric and contact mics is that they are not well matched to typical audio inputs. The reason why these devices often sound tinny is because the piezo sensor presents its signal through a series capacitance which is small, typically 15nF or less. When wired to a normal 50 kilohm line input this forms a 200Hz high-pass filter, which eliminates the bass. Because the piezo disc has a very high impedance (1 MΩ typical), it should be buffered to avoid possible impedance mismatch with an existing audio system. This circuit acts as a impedance buffer, and some amplification does not hurt as long as it is around 40dB.
Good video! Piezo transducers can also make a good shock or vibration sensor. Wired with an opamp they could make a somewhat decent microphone.
Very useful information 👍 keep experiment
Could use one in a homebrew CW rig to sound the sidetone. You could also use Frequensee to see the piezos sharp response.
I've taken apart headphones for repair, so I know there's a piezoelectric speaker, and that doesn't have the usual paper cone, their just a small disk with wires soldered to it.
Hi! - Do you know where I can buy lots of those Piezo with a feed back tongue? I want to make simple tuneable buzzers with a transistor, resistor and capacitor, to make a simple tuned pipe organ. Is there a special name for this type of Piezo disc? John N
Sorry John - no idea.
Now I know how this can be used in my i9040 alarms
SuperB idea & experiments, thanks!
Very Cool!!!!!!!
1:44 how to make a fart sound effect.
Hook it to an empty soda can for the amplification
The bowl works to
Very Good Piezo
Этому мужику кто-то челюсть сломал, если он говорит так, как будто рот не открывается? Кто знает, подскажите пожалуйста?
i think i can play clear 8bit music on that thing
teach us how to drive it , how to use it to take heart rate of a patient