producing electricity using quartz cristals?!

[bogdanfirst]

when a quartz cristal is swueezed it produces some electricity.
has anyone thought to use this for charging something?

or maybe use this electricity to power something?
these kind of things are used in lighters and other stuff.

has anyone actually built this???

 

[grrr_arrghh]

My first reaction is that it doesn't produce much, but then they can be used to produce a spark for a gas cooker, so they must produce a fair ammount of voltage. However, I suspect that to be able to charge anything would require a such a large ammount of energy into squezzing the crystal, that you could just be wasting power.

I suppose you could stick LOADS to the bottom of your shoe to charge your mobile phone....?

 

[udi_hakim]

You can make a vibration sensor,
When a piezo electric crystal vibrates it produces a small amount of electricity that can be measured.

But the amount of electricity is very very small, beside sensors i don't think you can do something out of it.

 

[John Sorensen]

Any time you think you've found power for free, think again.

j.

 

[evandude]

sure you can get high voltages from them... but think of the amount of shock that it takes to get that, with the spring mechanism, it smacks the crystal pretty hard. you would probably get a much lower voltage if you had it in your shoes, or whatever.

also bear in mind that they only produce electricity when they are in the process of being squeezed, not when they are held rigidly in place, compressed. so if you stuck one in a vise, you would get some electricity while you cranked it closed, but none if you left it in place compressing the crystal.

also bear in mind that voltage is not the only factor here; crystals surely produce an incredibly small current, and since power is the product of voltage and current, the actual POWER output would be incredibly small as well.

I believe there are watches that use piezo elements to keep their batteries charged... however bear in mind that watches use an insanely small amount of power to begin with... even using a much more powerful array of piezo elements, i think charging a standard-capacity battery would be rather impractical