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

[Tony Alfrey]

Tony Alfrey wrote:
> Tony Alfrey wrote:
>> 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.
>>
>>
> 
> Oh, wait, I see that the radioisotope is a beta emitter (electrons) so 
> no heat.  But it is essentially the same effect.  Just guessing:  very 
> much like a photocell (photons excite electrons across the band gap) but 
> in this case, it is electron collision doing the work.  Must be a 
> screaming beta source to get enough power, and all of the electrons 
> can't be absorbed so somethings gotta get hot.  I'll study it.  Thanks 
> for the link!
> 

Sorry I keep posting to my post but they are essentially as above:
"Betavoltaics generate power when an electron strikes a particular 
interface between two layers of material. The Process uses beta electron 
emissions that occur when a neutron decays into a proton which causes a 
forward bias in the semiconductor. This makes the betavoltaic cell a 
forward bias diode of sorts, similar in some respects to a photovoltaic 
(solar) cell. Electrons scatter out of their normal orbits in the 
semiconductor and into the circuit creating a usable electric current."



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