Switchable Magnets.

[synchro1]

Here's a good video on growing the Crystals from "Cream of Tarter" and "Baking Soda":

https://www.youtube.com/watch?v=E1Ct3VUWvhQ

[Pirate88179]

John Bedini showed how to easily grow large "Rochelle Salt" crystals for practically nothing. I was surprised to learn they generate the most Piezoelectricity. They grow like "RockCandy".

Piezoelectricity is the ability of certain materials to produce a voltage when subjected to mechanical stress. Piezoelectric materials also show the opposite effect, called converse piezoelectricity, where application of an electrical field creates mechanical stress (size modification) in the crystal.

piezoelectric 01

Figure 1 Piezoelectric effect

The effect known as piezoelectricity was discovered by brothers Pierre and Jacques Curie; they showed that crystals of tourmaline, quartz, topaz, cane sugar, and Rochelle salt (sodium potassium tartrate tetra hydrate) generate electric charge from mechanical stress. Quartz and Rochelle salt exhibited the most piezoelectricity.

The relationship between force and electricity is converse; The material compresses when electrified, and generates electricity when pressured.

Also, as I can speak from experience here, if you heat a piezo material, and discharge it while it is heated, it builds up a like charge when it cools and can be discharged again.

We had a job machining some piezo disks about the size of a hockey puck.  Like a lot of our ceramic machining, what we would do is to wax the pucks down to precision ground steel plates, (which held fast to the magnetic chucks on the grinders) surface grind the first side and then, demount them, clean them, and use a vacuum chuck to hold them to do the second side and take them to final thickness.

Well, we heated them up in order to wax them to our steel plates.  I accidentally got my finger near one of the pucks and a huge spark jumped out and bit my finger from about 1/4" away!  It really hurt!  So, I figured we needed to be careful with this material from now on when heating it up.  Once cooled, I went to mount the plates onto the surface grinder, and ZAP! I got hit again.  I called the engineer that we were doing this job for and he explained that if heated, it builds up a huge charge of thousand of volts. (no kidding)  Then, if discharged when hot, it cools and builds up a similar charge again.  I think the material might have been barium titanate but I can't really remember now.

Here is a link: http://en.wikipedia.org/wiki/Barium_titanate

Anyway, I just wanted to show that besides mechanical compression/decompression, piezos can also build charge in the way described above.

Bill

[synchro1]

Also, as I can speak from experience here, if you heat a piezo material, and discharge it while it is heated, it builds up a like charge when it cools and can be discharged again.

We had a job machining some piezo disks about the size of a hockey puck.  Like a lot of our ceramic machining, what we would do is to wax the pucks down to precision ground steel plates, (which held fast to the magnetic chucks on the grinders) surface grind the first side and then, demount them, clean them, and use a vacuum chuck to hold them to do the second side and take them to final thickness.

Well, we heated them up in order to wax them to our steel plates.  I accidentally got my finger near one of the pucks and a huge spark jumped out and bit my finger from about 1/4" away!  It really hurt!  So, I figured we needed to be careful with this material from now on when heating it up.  Once cooled, I went to mount the plates onto the surface grinder, and ZAP! I got hit again.  I called the engineer that we were doing this job for and he explained that if heated, it builds up a huge charge of thousand of volts. (no kidding)  Then, if discharged when hot, it cools and builds up a similar charge again.  I think the material might have been barium titanate but I can't really remember now.

Here is a link: http://en.wikipedia.org/wiki/Barium_titanate

Anyway, I just wanted to show that besides mechanical compression/decompression, piezos can also build charge in the way described above.

Bill

@Pirate88179,

It's possible to mold the "Rochelle Salt Crystal"; Look at the behemoth below: Molding "Barium Titanate Powder" into large ceramic blocks would work even bettor but cost a lot more. I bet this huge Crystal would light some bulbs vised by a "Magnet Chuck".

[synchro1]

This $300.00 "Dog House Climate Control System" and a sealed box would supply the strict uniform cooling temperature necessary to grow a  super sized "Rochelle Salt Crystal" like the one pictured above. A high heat ceramic kiln would be be needed to forge a "Barium Titanate" block from powder. A sufficient number of these large "Piezoelectric Crystals" coupled with the stable switch cost of multiple "Daisy Chained" Magnet Chucks should hit "Pay dirt" at some point.

[synchro1]

This is pure "Potassium bitartrate". 20 pounds would cost $172.00 including shipping.

Cream Of Tartar, 10 Lb Bag
from Angelina's Gourmet

Price: $75.25  ($75.25 / bag)  + $10.75 shipping   

A large Spaghetti pot, and a rectangular "mold form" positioned in the "Dog House" cooling box would crystallize a pure "Potassium bitartrate" slurry into a 20 pound Piezoelectric brick overnight for $172.00! Power 24/7 rain or shine!