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
Thermopile power supply in water heater control
Started by ●April 18, 2017
Reply by ●April 20, 20172017-04-20
Reply by ●April 20, 20172017-04-20
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
Reply by ●April 20, 20172017-04-20
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.