Joule Thief

[electricme]

Hi Tommy8482
Welcome to the Joule Thief thread.

Where did you come across this one? it seems to be driving the tube nice and bright.
The transistors look like they came out from the same stable to those that are in the disposable camera circuits. Nice big HI Voltage transformer there.

Jim

[WilbyInebriated]

Hi Tommy8482
Welcome to the Joule Thief thread.

Where did you come across this one? it seems to be driving the tube nice and bright.
The transistors look like they came out from the same stable to those that are in the disposable camera circuits. Nice big HI Voltage transformer there.

Jim

looks to me like a driver for a ccfl out of a scanner or such...

[tommy8482]

I think, this is an old scanner's cfl driver. I found it in my old stuff. I'd like to know what kind of transformer is this to replicate the circuit.

It seems, both collectors and bases of transistors are connected through transformer's coils.

(Sorry for my language if it is not correct.)

[electricme]

Tommy8482:

I spent a couple of hours last night trawling the net looking for info on that transformer and didn't find anything.
Only thing I could recomend, is you take it apart.
Find the top layer of winds, then locate the last turn and then undo each turn (keep a count) write down what end goes to what pin, keep doing this for each seperate coil/s until there are mo more turns left on the former bobbin, then you should have the info.
It's tedious and takes a fair time.
Hope this helps.

At All:
I found out that the tiny transformers out of disposeable cameras come apart more easily if you "boil" them in hot water, this soffens the glue so the 2 graphite halfs can come apart easier.
(Indestructables had this info)

Wilby:
Yes I think you are right, I can remember seeing one I took out of a very old scanner a few years ago, the tiny long thin tube was really something, so fragile, like a single strand of spaghetty!!!!


I don't know if anyone has noticed or not or if it is just me but my computer is taking forever to open Overunity webpages and it takes wayyyyyyyyyy to long, sometimes only the top half opens, the change came about because of the E-Bay twin screens have been added.
Has anyone else had this problem???

Lastly, I got a CFL to light up at last after several failures.
My public thanks to Pirate, Protonmom and WayneCL who have helped by sending me camera parts and parts.

I now have a voltage data logger which will be pressed into service, (my thanks to Wayne), but I'm learning how it works before I post some charts.

jim

[Flux4Energizer]

@All,

Is there anybody who has a good Joule Thief circuit for me???
I need a JT which can power up 1, 2 or 3 superflux leds from a single battery.
Amp draw is less important then brightness!!!
Leds need to be at least 80% bright.

Thanks