Piezoelectric circuit

I have two question:
1. Do I need a power supply for a piezoelectric circuit? (I am trying to make it behave as a switch)
2. Am just curious what current and output voltage levels can I expect from a piezoelectric crystal?


Thanks in advance

If you apply a voltage to a piezo, it bends.

If you bend a piezo, it makes a voltage.

It is a very high impedance device, it behaves like a small capacitor. It doesn't take much current to bend it.

When you bend it, it produces almost no current; just a voltage.

I have no idea how you propose to use it as a "switch"?

Wouldn't you connect it to a voltage clamping diode (to make the voltage unipolar) and then connect it to a debouncing circuit?

dknguyen said:

Wouldn't you connect it to a voltage clamping diode (to make the voltage unipolar) and then connect it to a debouncing circuit?

Click to expand...

Well, it is a rate-dependent output voltage, i.e. it puts out a voltage propational to the rate it is being bent. The polarity of the voltage is dependent on which direction it is being bent. That's why it will not make a "switch". Something else (like a flip-flop) would have to remember which direction it was last being bent...