Crystal Power CeLL by John Hutchison

[PaulLowrance]

MK1 just posted this link over in the JT topic:

http://blog.makezine.com/archive/2008/07/how_to_make_piezo_crystal.html

You guys may know all about this but 26 volts from Rochelle salt (pizo) held under pressure from a spring clamp?  This looks very interesting.  Thought you might like to see it if you hadn't.

Bill

That's amazing!  Is that a stabilized DC voltage, or does it go away when the pressure is no longer changing?

Paul

[ian middleton]

Thanks guys,
Well done Bill, you just had to do it. Put another idea in my head. Now I'll never get away for Christmas. .
Now where's that manhole cover. ( yes I do have one LOL  )

@Paul, the rochelle salt crystal needs to be bashed (shocked) to produce the voltage spike, it's a transient thing. However it may me possible to create an increased static field by squeezing it, I'll have to look into it. ( Thanks for the link Bill )

Ian

[PaulLowrance]

That's a worth while experiment. For me though, the piezo & diodes have always been extremely sensitive to even the slightest disturbance. If they're disturbed by pressure or electrical current the DC voltage decreases to almost nothing, but if it's highly disturbed then the voltage will often fluctuate all over the place before it takes a nose dive to nearly zero volts. But who knows, maybe if a lot of *constant* pressure is applied for say a few weeks to let it settle down, then maybe it will eventually produce a lot more DC voltage and/or current.

Hmmm, I wonder if the 10pA DC I'm seeing is related to the 1 ATM of constant pressure. Maybe I get to excited over piezos. 

[Pirate88179]

MK1 originally posted the link.

This does not make sense to me however.  We used to machine pizo material for, I have no idea what the project was, but these were the size of hockey pucks.  Since they were a ceramic material, we had to wax them to steel plates that would hold to our magnetic chucks on our surface grinders, which was SOP.  Well, we found out the hard way that when you heated this material...it built up a huge charge of thousands of volts.  when we touched it when it was hot, we got knocked to the floor.  Now, if that were not bad enough, we also learned (and it was later confirmed by the scientist that we were doing the job for) that if you discharge a pizo material when it is hot, it builds up a like charge when it cools and....ZAP again!

So, what does not make sense to me here is that pinching the crystals would seem to build up a charge but when tapped, it would go away and then releasing the pressure should build up a like charge, etc.  Unless the charge is very high and they are only slowly tapping it?  I just can't see how constant pressure would deliver a constant voltage like this but hey, maybe it does.

Anyway, I guess we will have to find out?

Bill

[Pirate88179]

Hmmm, I wonder if the 10pA DC I'm seeing is related to the 1 ATM of constant pressure. Maybe I get to excited over piezos. 

Paul:

That is an interesting thought.  5.5 psi might explain it.  I really wonder if anyone really knows?

Bill