I'm a total noob when it comes to electronics so was hoping some people might be able to take a look at my circuit and see if it makes sense.
I'm trying to create a circuit which amplifies the puny 50-100mV output (Vin) signal of a piezo transducer (with a gain of ~20), then feeds it into a comparator with a fairly low reference voltage on the inverting input, ~450mV (Vref), which has an output voltage (V2out) of 5V. This signal is then plugged into a digital pin on an Arduino.
Here's the schematic (sorry if the design is terrible - I'm still learning these things!):
Does that look okay? Have there been any egregious oversights?
One thing I've learned is that modelling piezo transducers is somewhat difficult, and that an AC voltage source (as above) is not ideal. Any tips on improving that would also be really appreciated.