Thermopile power supply in water heater control

Phil Allison <pallison49@gmail.com> wrote:
>>
>  ** The first  LT device I linked came from " 700mV boost converter" and the LT3108 is mentioned at the top of the first LT page . 
> 
>  Couldn't have been easier. 
> 
> 
8-)
"boost converter" never occurred to me......

thanks,
bob

bob prohaska wrote:
>
> Phil Allison 
> >>
> >  ** The first  LT device I linked came from " 700mV boost converter" and the LT3108 is mentioned at the top of the first LT page . 
> > 
> >  Couldn't have been easier. 
> > 
> > 
> 8-)
> "boost converter" never occurred to me......
> 

** Shame on you - there simply had to be one of 'em in some form. 

 I didn't know specific thermopile input ones existed. 

 Using a 1:100 input tranny IS a neat idea.



....   Phil 

On Wed, 19 Apr 2017 01:57:47 +0000 (UTC), bob prohaska
<bp@www.zefox.net> wrote:

>I recently bought a gas water heater and made a point of getting one
>that didn't require external electrical power to operate. 
>
>To my astonishment, it nonetheless came with what behaves like a digital
>controller, complete with a green LED status light that must require close
>to 3 volts to turn on. 
>
>The electronics are operated from a standard Honeywell thermopile generator
>producing 750 mV open circuit with a 3 ohm source impedance. I expected to
>find an explanation of how it's done via a quick Web search, but have so
>far come up with nothing very informative: Only that one can get MOSFET
>transistors "programmed", evidently by something like charge trapping,
>to have arbitrary gate threshold voltage, down to zero. That seems rather
>exotic for a water heater 8-)
>
>Can somebody point me to an application note explaining how this is done? 
>
>Thanks for reading,
>
>bob prohaska
>
>
Google "energy harvesting" and/or "Joule thief"
just for entertainment.

w.