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Quartz crystals and voltages

  1. Aug 2, 2008 #1
    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.
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  3. Aug 3, 2008 #2


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    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.

  4. Aug 3, 2008 #3
    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?
  5. Aug 3, 2008 #4


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    I'm no expert on piezoelectric crystals but I beleive the change in length is a nonlinear funciton of voltage. I would also think high frequency pulses might create fractures.
  6. Aug 4, 2008 #5
    "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.
  7. Aug 4, 2008 #6
    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.
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