I created this circuit as an example free energy from body heat.
Free energy which means source of power which you don't have to buy or make.
Our Body radiate heat 24 by 7 as long we are alive.
I decided to use peltier merely using my body as the heat source(36.5C) and cold side is my tropical room temperature(30c).With mere 6c difference i was able to power Led not to mention this circuit have the ability to trickle charge any device as well.
I am using N-channel Junction FET:2SK170 to achieve the self starting oscillation at such a low voltage 25mV.The circuit only consume (4.2mA at 60mV) input.The open circuit voltage is around 8volts with 2 leds in series it is 4.3v(Leds dimly lit).
The circuit is able to work on single FET but to increase efficiency i had to use 4 FET connected in parallel which also increase current draw to 4mA.