Piezo Igniter capacitor storage

Discussion in 'The Projects Forum' started by Evix, May 3, 2016.

  1. Evix

    Thread Starter New Member

    May 3, 2016
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    I want to store the energy from a piezo igniter that i took from a lighter into a small cheramic capacitor.
    The voltage is a Over 10kv or 12 kv according to forums i have read on.
    What i have seen so far a generator and a few diodes can do this but i dont know what type of generator i should usel. 90:1 som say but where do i find one for my specifications. I have looked everywhere to but a generator for it but im no wiser. The size aswell must be tiny.
    Any easy way to do a stepdown of the voltage? Ideas of how to do it or where to find components? Or what are the components named?
     
  2. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    Hi and welcome to the forum!
    What you ask should be possible, but we need a lot more details to get better understandind on what you want.
    Why a generator, do you you mean a transformer?
    Also, what do you plan to do with the stored energy, and why does it have to be tiny and what does tiny exactly mean?
     
  3. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    Taser are current limited to prevent death by heart attack. A cap charged to the high kilovolt range is NOT a current limited device and contact with it while fully charged could be deadly.
    What farad rating are you considering? Micro, nano, pico?
     
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  4. Evix

    Thread Starter New Member

    May 3, 2016
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    Yes i mean a transformer.
    The energy should be used for a batteryless device. The device Will be a wireless transmitter.
    So im only gona store 1 click from the piezo igniter. Therefore i want it to transform to low voltage and higher ampere.
    Cheramic Capacitor of 4,4 uf might do.
     
  5. Evix

    Thread Starter New Member

    May 3, 2016
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    And i was considering to transform 10-12 kv to around 30 volt.
     
  6. Sensacell

    Well-Known Member

    Jun 19, 2012
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    Not really a workable idea.

    Igniters produce a very small amount of energy, trying to store and transform this energy down to a usable DC voltage is complex and difficult, considering the huge ratio of voltages involved. Not many semiconductor elements can withstand 10kV.

    10,000 / 30 = 333:1 !!
     
    Last edited: May 4, 2016
  7. Evix

    Thread Starter New Member

    May 3, 2016
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    Im pretty sure its doabel with less windings. 90:1 is fine. But as much windings would be Great. And size is importen of the transformer.
     
  8. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    I think that if you put said voltage straight into a capactior it should be able to charge it to some reasonable voltage. I would start with some large ceramic caps and see how much energy is there and what is the polarity of the voltage.
     
  9. tcmtech

    Well-Known Member

    Nov 4, 2013
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    A piezo electric element only puts out 10 -12 KV if it has no load on it.

    If you connect one through a small bridge rectifier (They actually put out AC. One polarity on compression and the other on rebound) you can use the tiny current pulses to directly charge up a capacitor and use a common Zener diode across the capacitor as a voltage limiter.
     
  10. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    According to this article you can expect ~70uJ of energy per piezo click. If you use a 4.7uF cap, that should theoretically (100% efficiency) charge to √(70uJ/2.35uF) volts = 5.5V with one click. Sourcing a suitable high-enough voltage rectifier at a sensible price might be a problem.
     
  11. Kermit2

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    Feb 5, 2010
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    If it was cheap and easy to do...it would already be found all over youtube.
    Do it, and become a trailblazing pioneer in the field of electronic hacking and a new Internet sensation.

    :)
     
  12. MrChips

    Moderator

    Oct 2, 2009
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  13. tcmtech

    Well-Known Member

    Nov 4, 2013
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    Why would a HV rectifier be needed for a low voltage system?

    I can fire a 12 KV 60 mA high output neon sign transformer through a common 50 volt bridge rectifier to charge a large capacitor that has a simple zener diode based voltage limiter all day without exceeding the rectifiers voltage limits as long as the capacitor charge is kept under the 50 volt limit of the rectifier diodes.
     
  14. Kermit2

    AAC Fanatic!

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    If the capacitive load is causing the piezo output to fall into a less than 50 volt range, is the transducers already pitifully low efficiency even further reduced?
     
  15. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Good point. Didn't have my thinking cap on :D.
     
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