So the whole problem revolves around the fact, that i need to drive the piezo to the highest possible DB-level from a 3v battery. I've designed and 3D-printed a resonance chamber which seems to work okay. My biggest succes has come from driving around 4.6kHz from the output arduino pin to a transistor and from there to a parallel setup with a 4.7kH inductor and the piezo. The piezo is measured as 18.5nF which by my calculations should result in a ressonance frequency around 17068Hz. However this is far from where i get my highest voltage when measuring vAC. Around 4.6kHz is where i get the highest voltage (around 6.2vAC). Any suggestions on how to increase the voltage across the piezo? My current setup just doesn't seem to cut it. It needs to be louder (it's for an alarm) Thanks again for inputs!
Presumably you don't mean 4.7kH ( 4700H)What value is it?Allan
Putting about 80mH in series with the piezo would give a reasonable current through it at 4kHz - see enclosed.The voltage depends on the internal resistance of the piezo.Allan
You've drawn a parallel resonant circuit which presents a low impedance except at resonance - and only allows twice the supply volts across the piezo.A series resonant circuit becomes low mpedance at resonance, and forces a lot of current to flow through the piezo. It has no such limitation .If you used my circuit with a 56mH and added a 2.2nF across the piezo you'd also acheive resonance, and it ought to work at about 4.6 kHzNote you can't use a single transistor driver here - try an arduino output to start with and tweak the extra C for best output.Allan
Try it my way with a signal generator. And do some sums .And download and learn to use simulation programmes such as 'PSPICE' or 'LTSPICE'.You'll find them very useful.Allanedit : you may find the enclosed driver useful - put the inductor/piezo where I show the loudspeaker.
And the 3.3v from the DC source doesn't affect the output at all