Joule Thief

[electricme]

@ ist
I noted you got probs with the solar cells, ie low output .5v

Solar cells can be designed to operate best in bright sunlight or overcast days.
Some perform better if there is IR.

Try a different (light) frequency and let us know what happened

When you get the best output, try connecting in series and in series parallel (if you got enough solar pannels)

jim 

[Pirate88179]

I think you will enjoy my latest video.  You can view it here: http://www.youtube.com/watch?v=27QJ92ruzeE

What I did this time was to wire 2 Fuji AA circuits in parallel but, I only used 1 battery!!!  I lit a 48" tube and you can see in the video how bright it gets when I switch on the 2nd circuit.  I think this is significant and it is telling us something.  Please look at this and tell me what you think.  I believe this will directly apply to our toroid circuits as well.  Thank you.

Bill

[jeanna]

I think you will enjoy my latest video.  You can view it here: http://www.youtube.com/watch?v=27QJ92ruzeE

What I did this time was to wire 2 Fuji AA circuits in parallel but, I only used 1 battery!!! .  Thank you.

Bill

I guess this it the way. Parallel.
today I only used a toroid for the second and it did not step it up. So, tomorrow, I guess, i'll go to work with some multiple wires on one toroid. I think without another resistor/transistor, there is nothing to be gained from adding a second toroid.

Nice video. My screen stopped to buffer just when the brightness flushed, and before the camera adjusted. It really is good and bright.

Would you be willing to see how long this will run?

jeanna

[xee2]

@ ist

I think that your last scope shot (both_coils_bigger_spikes.jpg) shows best what is happening. The spikes are the voltage when the LED is off (same as open circuit). When the LED turns on the voltage across it will be limited to the forward drop of the diode (about 2 to 3 volts).

EDIT: a diode does not obey ohms law.

[xee2]

@ jeanna

If you want the LEDs to be as bright with two toroids in series then you will have to double the battery voltage so that the voltage across each coil is the same as with one coil. Bill was able to run two JT in parallel because the battery could provide twice the current. In series requites more voltage, in parallel requires more current for same brightness.