The Curie point of nickel is just 350 Celsius, so at that temperature it isn't attracted any longer to WHATEVER STRENGTH(!) magnet(s).
Effectively an OFF/ON switch.
Since much higher temperatures can easily be obtained with (Fresnel) lenses, how about solarizing Tesla's idea :
A non-magnetic lever, attached to a flywheel/generator with, say, 500 kilos attached to the lever.
Top of the lever covered with a nickel strip.
Above the lever a row of magnets capable of lifting, say, 750 kilos, aligned with the nickel.
Magnets protected/covered with a heat-resistant material or something, you don't want the magnets to heat up lest they be destroyed, thus defeating the purpose, hehe.
Solar focused on the nickel via (Fresnel) lens, heats up to 354 degrees C, isn't attracted any more(Curie point), lever drops, powers the flywheel.
Nickel cools, lever is attracted, up it goes. We have a cycle, long as the sun shines and depending on how fast it gets below CP again.
To obtain greater action of the lever, use more (powerful) magnets or less weight.
And never mind it's slow, it's the principle that counts : lifting substantial weight by cooling the connection below 354C and dropping that weight by heating the connection above 354C.
Maybe even some of the energy harvested can be used to cool the link more quickly ;D.
Tesla patent (http://www.google.com/patents?id=r3BFAAAAEBAJ&dq=396121)
YT Curie engine (http://nl.youtube.com/watch?v=RWrTvB-oK94)
I like this idea, or one of it's variations :)
It's simple and doable by most anyone, and would probably not require
anything more than buying off the shelf parts. I haven't run the numbers,
but I expect they would prove to be in the positive.
tak
@JoinTheFun
May I draw your attention to another thread here with the same idea and a suggestion on what I read on an interesting material, gadolinium:
http://www.overunity.com/index.php/topic,4785.0.html
Unfortunately the price of gadolinium is rather high to tinker with... There may be other types of suitable material though. The lower the temperature of Curie point, the easier it is to cool it down with respect to its ambient temp.
Thanks, Gyula
I am fond of simplicity, an even simpler construction is possible :
Instead of nickle attached to the lever, switch it around, so the nickle would be topside, easier to aim solar at it and the magnet(s) are instead attached to the lever, making it much easier to isolate them from the heat.
When the lever is down, the nickle has to be shielded, so it can cool down.
Btw, 1 and 2 Euro coins contain nickle, but how much remains to be found out.
Canadian nickles of a crtain period are almost pure nickle.
Someone know of other stuff that contains much nickle ?
Somebody already trying this ?
I did a quick look around for other low Curie temp metals, and found NI-SPAN-C alloy 902 from Special Metals that has a Curie temp of 190 degrees C.
http://www.specialmetals.com/documents/Ni-Span-C%20alloy%20902.pdf (http://www.specialmetals.com/documents/Ni-Span-C%20alloy%20902.pdf) Not too sure if the permeability of this is suitable though?
Probably my first thought of 'off the shelf' for parts isn't quite correct. :)
How about solar for the heating and geothermal for the cooling?
tak
The lower Curie point is not worth the effort, cause focused solar easily reaches 1000C and up, as you can see here, melting glass :
http://www.youtube.com/watch?v=DGtA8E5iw3k (http://www.youtube.com/watch?v=DGtA8E5iw3k) 5m20s into this clip.
The cooling down would be no problem either, that happens by itself in any case if the metal is shielded.
Come to think of it, with these kinda temperatures other metals could be used as well as nickel.
;D
Found a cheap way to get nickel :
pure nickel guitar strings !