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A Closer Look at Piezoelectric Crystal(samaterials.com)
68 points by pillars 13 days ago | 23 comments
  • throwpoaster4 days ago

    Related: the triboelectric[0] effect.

    [0]: https://en.wikipedia.org/wiki/Triboelectric_effect

  • wizardforhire4 days ago

    Obligatory must watch old dod training film on the subject.

    https://youtube.com/watch?v=ZYyAYIUvI-M&pp=ygUiUXVhcnR6IGNye...

    • thenthenthen4 days ago |parent

      As well as Crystals go to war, on the industrial production of crystal oscillators: https://youtu.be/wHenisSTUQY?si=GzjfOFHFOknKRQ9m

    • mikkupikku4 days ago |parent

      I wish people still talked with the accent/style used in these old videos. It's so easy to understand and listen to, compared to the typical modern American accent.

      • ahartmetz4 days ago |parent

        It seems to be https://en.wikipedia.org/wiki/Good_American_Speech aka Mid-Atlantic Accent - an artificial accent - with a fairly strong natural accent of the speaker coming through.

        • kulahan4 days ago |parent

          What is an artificial accent? Isn't every accent just the way people choose to speak?

          • mitthrowaway24 days ago |parent

            An artificial accent is one where there are no native speakers raised with it, but rather people are professionally trained to speak with it.

          • FuriouslyAdrift4 days ago |parent

            It's a way of speaking taught in broadcasting and acting schools

            • kulahan4 days ago |parent

              I was under the impression that this is effectively teaching people to speak without any accent at all

              • mrguyorama4 days ago |parent

                >effectively teaching people to speak without any accent at all

                There's no such thing as "no accent"

                • NetMageSCW2 days ago |parent

                  I used to speak with pretty close to no accent as I learned English in Okinawa, then went to 2nd and third grade in Arkansas and then went to school in southern Virginia. The mix resulted in an unaccented speech compared to most localities. Now I have a slight southern accent.

                • ahartmetz3 days ago |parent

                  In English at least. Some (maybe most? - no idea honestly) languages do have more or less official standard accents. For German, that standard accent is very close to how people speak in Hannover.

              • FuriouslyAdrift4 days ago |parent

                Oh no... it's an "accent". It's just a "desirable" one. Kind of like a posh accent in England.

                • kulahan4 days ago |parent

                  Well no, definitely not - it’s just meant to be as clear as possible. The point is to make sure as many people as possible can understand you, which is very important in informational and entertaining broadcasts.

      • FuriouslyAdrift4 days ago |parent

        The midwest has the most neutral accent although it is slowly drifting

        https://www.babbel.com/en/magazine/the-united-states-of-acce...

  • csours4 days ago

    Synthetic quartz growing:

    https://www.youtube.com/watch?v=oFH8_uLzano

    https://www.youtube.com/watch?v=lzHqhNoyx2o

  • sixothree4 days ago

    Do we still use piezo to power clock circuits of modern computers?

    • nakamoto_damacy4 days ago |parent

      no, we use atomic clocks now... j/k

      piezoelectric refers to generation of electricity from pressure applied to the material... the inverse of that effect is what generates oscillation.. quartz has a natural resonant frequency determined by its shape, size, and the way it’s cut, and when you apply AC it oscillates at a specific frequency.. the applied electricity causes is the material to deform.. that is the basic physical effect used in oscillators

      MEMS oscillators are increasingly replacing quartz in compact, rugged, or integrated designs.

      PLL-based frequency synthesis is used to scale a low-frequency reference (e.g., 25 MHz crystal) up to CPU/GPU GHz speeds.

      • willis9364 days ago |parent

        MEMS are made on a different process than other silicon devices, which slightly increases their cost. They also need to have hermetically sealed packaging, same as quartz. Together there is little fundamental savings to be had with MEMS, but they do offer a higher ceiling on performance. I don't see crystals going away anytime soon.

        Also, if you get a MEMS in a small epoxy / CSP package be weary of gases that permeate the packaging material, such as helium.

        https://hackaday.com/2018/10/31/helium-can-stop-your-iphone-...

  • panki274 days ago

    The link appears to be broken, it redirects me to the main page.

    • zenmac4 days ago |parent

      https://archive.ph/E4TZ7

  • southwindcg13 days ago

    *Crystal

    • pillars13 days ago |parent

      Thank you! Updated.