Joule Thief 101

[tinman]

Ah.. OK, they are probably all in parallel then. You could test that by looking at the voltage required to turn the lights on, should be the same as for a single separate LED, rather than twice or three times that much. Sometimes these setups even include a small current-limiting resistor tucked away on the PCB.

I have a 24 LED array that came from a cheap LED flashlight that used 3 AAs,  that was originally all LEDs in parallel, with a tiny resistor, but I rewired it to be 2 series arrays of 12 parallel each and ditched the resistor. I use this for some JT demonstrations (but not of course for our testing here.) 
Yes, I'm sure that explains it, the focussed beam and the close distance. That's the problem with using Lux, it is a measure of the illumination falling on a surface rather than the output of the light itself, but that's all we have to work with. The 1.5 volts must be for the JT measurements, not the single DC equivalent point, right? As the LEDs in your 9-led array will not shine with only 1.5 volts DC, right?

Anyhow, I figured that the numbers on your graph were in the right place and the grid lines were misplaced, so it didn't really cause me much grief. But really, for great ease in recording and organizing data and turning it into graphs, you could try using a spreadsheet program like Excel or (free and fully functional) LibreOffice Calc:
https://www.libreoffice.org/download/libreoffice-fresh/
(scroll down for the Windows or OSX version installers)
Once you've gotten the hang of graphing using Calc (or Excel), you'll never go back.
The really nice thing about using the spreadsheet program is that if you change your data once you have the graph set up, like to correct an error or just to see how it affects the graph, the graphs change instantly and automatically to show the change. And once you have a graph set up like you like it, to graph a different data set you just need to copy-paste the original graph and then point the copy to your new data set (and edit the titles and other names of course). That's how I did the three graphs I posted up above. It's a snap.

Thanks for the info on the graphing,i wll download it tonight.

And yes
,the 1.5 volts was only for the JT, not the DC,that is why everything is in  watts.
Also not sure if the light meter gives an accurate account of light,being as i seem to get more light output from my custom made torroid than i do with straight DC-have to look into that a bit  more..


Brad

[minnie]

And when the battery voltage is at 1v,little r is how much ?

Brad

Oh,you're just too clever for  me!
         John.

[TinselKoala]

Some actual EE types discussing JT:

http://www.eevblog.com/forum/beginners/bench-psu-joule-thief-experiment-constant-current-vs-voltage/

[ramset]

Tinsel
Very nice link ..
I like the mention of "Gapped core" [sliced toroid]  energy storing characteristics too.

@Brad
"your" custom made Toroid showing some odd results Huh ......?

maybe a Gap could really Dice it up and some external magnets...

* Just Musings on Gunderson's  latest share...member Reiyuki's  musings got me thinking .

custom Core material [and Gapped architecture] a very specific Switching methodology and a magnetic wrap ...array ... causing  a Magnetic implosion ??
we are after all at an OU forum.
and A JT circuit is probably a very good Place to Muse ...

where Did Smoky 2 go ? all that very helpful and informative Core material / Resonance spec info he was sharing...

Like a cool Breeze of fresh air 



thx
Chet K

[minnie]

   Good Koala,don't you just have to love that Dave?
    He shows how to calculate the capacity of an AA
   energiser cell, that should keep the old tinman
   occupied for a week or two!!!
   Perhaps that should have read "measure".
        John.