Joule Thief

[jeanna]

OK gang, have a look.
I bought this to make it work and at $6.88 I am not afraid. In any case experience has shown me that these overly bright led lamps from china rarely last longer than 6 weeks, so what's to lose??
thank you,
jeanna

@gadget

Well if you are using pure ac then you need to reverse the connection to the LEDS . one way is dull the other BRIGHT BRIGHT . At least these are the conclusions i came to on any Number of white leds also the resistors are butting you circuit on your Very powerful JT . Question . Does this very powerJt light 20 leds bright . then if yes jump the resistors on your new light ..be careful .

The string o leds was set up that way for normal ac.
My secondary had some polarity, but I am trying to describe something different.
It has a grey color.
I want to say that is is suddenly more off than on to produce this frey color.
It is different from a lower battery, somehow.
And I have already jumped one and will continue.
This is informing me about the nature of inductors etc, therefore all my questions... sorry.
thank you,
jeanna

[jeanna]

I just found something else!
The inside rail is the pos side.

After 3 leds there is a break in the trace on the leds at the pos rail.

here. Look in the upper half of the picture.

So, I think this means I have effectively 6 leds and not one... right?
thanks,
j

[protonmom]

Excuse me for cutting in here for a moment.  I need to ask a "stupid" question.  Those three instant cameras I had taken apart sat arouind for a while.  I FINALLY decided to "short" the batties and remove them so as to get started on my first joule thief.  Well, I tried all three batteries, and NOTHING!    No short, no arc, nada!  Do the batteries lose their charge after a while?  Here I was, all prepared to be shocked, and dreading it, and Nothing!  So I was worried that perhaps I am doing it wrong, but how wrong can I be?  I shorted across the two terminals of the battery with an insulated screwdriver, just as told.  I am assuming the three just simply lost their charge, but I would like to know for sure.  Again, sorry if this sounds stupid, but remember I am just starting out in any kind of electronics.  Any help would be appreciated.  Thanks

[IotaYodi]

Well, I tried all three batteries

Dont you mean capacitors? Capacitors do lose there charge over time. If you shorted out the capacitors already then check them with a meter set on dc volts.
Check the voltage rating on the capacitors to determine what setting the meter should be on.

[jeanna]

....  I FINALLY decided to "short" the batties and remove them so as to get started on my first joule thief.
... but remember I am just starting out in any kind of electronics.  Any help would be appreciated.  Thanks

Hi protonmom,
I think you are talking about the capacitor.
You would need to charge the capacitor first by pushing the charge up button... ... then the red or white 'ready to flash' light would go on... ... then you could take your pic and the flash would be charged. 
Well overcharged.
And they don't lose it all when they are used hence all the fal-de-rol about shorting the cap before you start.

Mine were never charged when I got them either.
(I did charge them with the button and discharged them with a screwdriver. And then I did it again cuz it was fun until I saw the charred spot etc.  )

Carry on.
You are doing fine.

jeanna