Help on theory of this circuit

[rubberlele]

Hi...im a newbie in electronics and i have found a circuit on the internet.
However since im a newbie, i cant understand the working process and the theory behind this circuit. Hope those electronic experts can help on some explanation here(the longer the better)

 

[JimB]

This circuit has been discussed here in the last few months.
I cant remember which thread, but do a search using "solar".

JimB

Edit: I just did a search myself, it was you asking about it on October 17th!

 

[rubberlele]

yes it was me, back then i was asking whether the circuit will work or not. and now im hoping to know the explanation of the circuit, how it work etc