A Closer Look at Piezoelectric Crystal

62 pointsposted 10 days ago
by pillars
(samaterials.com)

22 Comments

wizardforhire

a day ago

Obligatory must watch old dod training film on the subject.

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

mikkupikku

a day ago

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.

ahartmetz

a day ago

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.

kulahan

a day ago

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

FuriouslyAdrift

21 hours ago

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

kulahan

20 hours ago

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

FuriouslyAdrift

20 hours ago

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

kulahan

20 hours ago

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.

mrguyorama

18 hours ago

>effectively teaching people to speak without any accent at all

There's no such thing as "no accent"

ahartmetz

13 hours ago

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.

mitthrowaway2

20 hours ago

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

sixothree

a day ago

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

nakamoto_damacy

a day ago

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.

willis936

a day ago

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-...