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Small Piezoelectric Application, will it work?

  1. Apr 10, 2014 #1
    I am planning to do a small project based on piezoelectric effect.
    The idea is to sandwich a piezoelectric crystal in-between metal plates and use it as a school bell or a small calling bell. I am planning to use a battery (need not be full, which holds charge enough to ring the bell for the first time). The battery rings the bell and vibrations are produced. The vibrations would be converted to electrical energy which is utilized for re-charging the battery. And by doing so a bell which does not depend on the consumer electricity is produced. The main idea is to make it work during power cuts.

    I am planning to implement the circuit http://ej.iop.org/images/0957-0233/23/1/015101/Full/mst399991fig10.jpg

    The battery in-turn is connected to the PZT crystal. Using switch, charging and discharging operation can be established.

    Will this idea workout? Are there any flaws?
  2. jcsd
  3. Apr 11, 2014 #2


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    If you ring the bell and then try to get the energy back, you will quieten the bell.
    It would be better to ring the bell less and let all the energy radiate as sound.
    This looks a bit like an impossible perpetual motion machine. It would be very inefficient.
    You would be better using a hand cranked generator as the bell button. The customer could then provide the energy to ring the bell.
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