Is this Kosher or am I just wanting believe in a perpetual motion genorator?

[Tony Alfrey]

James McDonald wrote:
> http://www.devicepedia.com/news/betavoltaic-batteries-offer-30-years-of-functioning-without-recharging.html 

These are the same types of power source that are used in deep-space 
probes, such as the Cassini spacecraft.  They consist of a heat source 
(the radioisotope, Pu238 in the example of Cassini, an alpha emitter, 
possibly Po210 in this battery) and an array of semiconductor junctions 
that utilize the Seebeck effect, the same thing responsible for the 
small voltage created when heating a junction between two dissimilar 
metals (such as in a thermocouple).  So it is essentially the same as a 
whole bunch of thermocouples wired in series, with a heat source.  The 
ones in spacecraft are run brain-splittingly hot, but clearly this one 
cannot be *that* hot.  Hotter generates more power.


-- 
Tony Alfrey
tonyalfrey at earthlink.net
"I'd Rather Be Sailing"