Piezo electric pressure sensor outputs

[darrylwm]

First a little backgound info. Trying to use my Roland edrums to replace the drum controller for Rock Band 4 (XBox 1). Both edrums and RB drum controller use piezo pressure sensors. The only difference is RB uses a 20mm disc and Roland uses a 35mm disc. Question is, with the same striking force, what differences in output could I expect from the 2 sensors? Simply a larger voltage spike on the larger disc? I understand that the discs output a diminishing AC voltage that lasts a few milliseconds and have seen small 20mm disc tested on UTube with a maximum output voltage of approximately 5 volts. Any insight would be appreciated.

 

[PETERDECO]

Welcome to the forum. Yes you can expect a slightly larger spike with the larger disc but may not matter at all if the circuit is sensitive enough. We use both 20mm discs and flexible piezo sensors at work. The flexible one produces a higher output but the discs work equally well with our circuit.

 

[darrylwm]

Welcome to the forum. Yes you can expect a slightly larger spike with the larger disc but may not matter at all if the circuit is sensitive enough. We use both 20mm discs and flexible piezo sensors at work. The flexible one produces a higher output but the discs work equally well with our circuit.

Actually, it's the opposite I'm concerned about. I'm replacing the 20mm discs with the 35mm discs. Will the higher voltage spike damage the circuit? Can I put a resistor in series to lower the spike? If so, how much?

 

[PETERDECO]

I wouldn't worry about it. We use a disc or flexible piezo with a 1 megohm resistor in parallel with it. There is a limit to how much of a spike that can develop across the 1 meg load because piezos produce only a small amount of current.