Maximum Drive Voltage for Quartz Crystals: How Much Is Too Much?

[Idea04]

When it comes to the piezoelectric effect you can have a small quartz crystal and apply a force to it and get thousands of volts as a result. But if you took a quartz crystal and applied a thousand volts to it, would it just crack? For a quartz crystal to take a couple thousand volts charge (no current applied to the quartz just voltage) would it have to have a larger size to take the extra voltage. I'm thinking the higher the voltage applied to the crystal the more the molecules move.

 

[dlgoff]

When you apply stress or deform certain crystals they produce an electrical potential across the crystals lattice. When you apply a potential across a crystals lattice, you get the reverse. The crystal will change it's shape.

 

[Idea04]

Yes but can a quartz crystal withstand a large voltage in the couple thandsands of volts range. From what I was researching the crystal only moves around a nanometer when a voltage is applied. but does that movement increase to a larger amount when the voltage is increased? With a high enough voltage will the crystal break?

 

[dlgoff]

I'm no expert on piezoelectric crystals but I believe the change in length is a nonlinear funciton of voltage. I would also think high frequency pulses might create fractures.

 

[fedaykin]

"I would also think high frequency pulses might create fractures."

I wonder if you could cause the crystal to crack (perhaps on an extremely small scale) through resonance in this manner.

 

[zeitghost]

I suspect that if you applied kV to a quartz crystal it would fracture.

The manufacturers list maximum drive voltage in their specifications.

Watch crystals are particularly sensitive, being designed to work with very low power levels.