Piezo sourcing help?

Does anyone know where I could buy a handful of piezoceramic vibration units, of the type used in mobiles/cellphones? I can only find people selling them by the thousand.

Also, does anyone know where I could find out more about these things, in layman's language? I'm interested to know things like how much power they use, whether they can be made to vibrate at different intensities/frequencies (by altering voltage?), what sizes they come in, and all sorts of basic questions. I've an idea I want to try to build, an am quite technically competent, but don't know the first thing about electronics! Any help appreciated.

Thanks

Kate

PS - if you want to email me, you'll need to edit the address!

AFAIK the usey small electric motors with unbalanced weights on the shaft.

not by much, go too low and they don't spin up, too high and they don't last too long.

someone cut one up and posted the pictures in alt.binaries.schematics.electronics a few month back.

Bye. Jasen

I have used them by the hundreds, they are just dc motors, the smaller 4mm thick body , and others up to 6 or 9 mm. Length 20-30mm. Attatched to the shaft is an excentric weight, and they run on a nominal voltage(depending on type) of 1 to 3 volt. We used them in a vest as 3 dimensional display on the skin and had an astronaut from Holland wear that in a few experiments in the international spacestation.(google vest tno). There is also a pancake model,(thin 2-3mm disk 10-12mm diameter) either as a stepper motor, or a dc motor. They left onethird of the rotor inside open,so no other excentric weight is needed.