This is the result of an 8 hour test in full darkness. The goal was to have the same watt consumption and lumen's after 8 hours. despite the battery slowly going flat. Didn't quite work. And I forgot to include a control (http://www.facepalm.org/). But I think it lasted longer at higher brightness than without LDR. At the start of test I had 1.190v in battery, with circuit connected (1.235v no load) running @ 3.88ma. which works out to .0046172 watts. After 8 hours continuous running. I had 1.091v @ 3.150ma or .0034335 watts.
So I need to make it increase amps more as charge goes down. Shouldn't be too hard though :)
I'm declaring this proof of concept.
This will be all on this for a bit. Now I've got proof of concept. I need to do a proper study and Prototype tuning. It's not working quite right but it does work.
Going to need to adjust sensitivity of LDR by putting another resistor across its legs( to lower resistance and increase sensitivity, adding resistor to one leg should do the opposite).
I also need to make a few identical circuits. So I can do better comparisons. Need to get rid of more variables to continue with this further. All that takes time. I may cheat a little and buy some pre-wound opposing bifilar coils. Although I'd prefer to keep working with toroid's, as they take best advantage of the nature of electromagnetism. I also need to do it taking a lumen or MCD reading at start and end of test. The meter showing amps has a wifi data-logger, so I might get the software for that installed too :) I'll post more on this when I have stuff better sorted.
I also need to get my scope calibrated... Hopefully I can find someone local with a good power supply...
If you can make a joule thief. I should have provided enough info here for you to replicate this. If anyone wants more help, just comment below or send me a message. I'd really like it if someone else can play around with LDR's to control this kind of circuit.
Obviously by putting this up here I want to open source everything. So it's all free to use.
Have fun people and Thanks for watching. Don't forget to hit the like button and subscribe to my channel so you don't miss my updates.