[email protected] wrote in
Is there any easy way to test the resonance on a piezo disc
transducer? I have a few and need to know the resonance before I use
them in a circuit.
Resonance of a diaphragm is more a physical thing than electronic. If you
can get it mounted in your intended case, assembled and filled as close to
final result as you can easily get, you can test it.
Two ways: One is to put a microphone close to it, wrap the head of the mic
in a sock to damp all but the most immediate and direct signal path, then
send a slow square wave with sharp edges into the sounder, record the
microphone signal at the best sample rate you can get, and examine the
overshoot of the waveform. The square won't make it through a DC blocker,
but the overshoots will. Use plenty of mic gain, and avoid live feedback.
Second way is esier but has more room for error, sweep the frequency of a
sine wave with constant amplitude, and record the output as before, but
there's no need to be as careful with the mic placement, you're just
looking for peaks of higher amplitude. If you find a strong narrow one,
look closely at it (Spectrum analyser in Sound Forge or GoldWave or Cool
Edit) to get the frequency.