Ultra Low voltage 45mV Joule Thief -Potential to be powered by peltier using body heat only
This latest circuit is indirectly influenced by youtube user
"Larskro" - Title Joule Thief very very low input 0,136 volt
"jonnydavro" - Title Reverse joule thief-Silicon transistor mystery
I wanted to come up with a ultra low voltage joule thief that could be powered by peltier merely by using heat from our body or hand and cold side(surrounding) if used together with a tiny heat-sink.Before i begin the "key secret" in getting white Led working at 52mV or red Led at 45mV lies in the selection of transistor itself.That the primary reason why i am using Japanese transistor 2SD1450 is because it have the "very low VCE" base on datasheet(0.13v to 0.4v).
Latest Japanese 2SD series transistor may have even lower VCE at slightly higher current.
The optional circuit is merely there to measure the voltage across leds but take note it does lower efficiency of the circuit such that the circuit stop at 49mV instead of 43mV.
If anybody plans to use peltier with this circuit please try to match the impedance of peltier with the 18AWG coil,it is very important.Lastly please do temporary short emitter and collector of transistor to kick start circuit.The ultra cap was temporarily charged for 1..3sec to get around 100mV from a AA battery.
Video was filmed using Sony Alpha Nex-5N camera