Joule Thief

[electricme]

In this series of USB Microscope photos I am showing the Transistors.
All of these I took off the same looking PCB disposeable camera boards, it wasn't until I could actually see them displayed on my screen when I became aware that although they all looked the same they in fact wern't, but were different in item numbering.
You can see for your selves.

jim

[electricme]

Here is the 5889 3G transistor

[electricme]

The next 3 transistors are D2470 W, D2470 N, D2470 V
Wea need to findout more info about these transistors, I think they are SCRs or silicon controlled rectifiers, might be wrong too.

[electricme]

One of my Kodak disposable boards is different, and so I have a few shots of what the components look like blown up big time. You will see that one item is of an unknown value, it is not marked and so tomorrow I will unsolder this item (if I don't break it) and measure it.
Remember, these are really small transistors and resistors, to see what they actually look like, if you have a similar board, just get it and turn it over, track side up.

2AL, 8AY1 (Y is on it's side), last item is the photo of just a small section of the PCB.

jim

[electricme]

All:
Transformer Problem

I have 7 identical Kodak PCB boards from the disposable cameras, I wanted to know what the value of the coils were and which pins are assoceated to each coil
I unsoldered all the coils and conducted the following test to every transformer, and I got identical readings and I tripple checked them all.

I put the transformer upside down with the 3 pins across and away from me, which leaves the bottom 2 pins towards me.

There is no numbering of the pins on these transformers and that is part of the problem identifying them, so I have decided to number them in the following order.

top left to right, P1  P2  P3
Bottom Left to Right P5  P4

So from a clockwize view, P1-P2-P3-P4-P5

I measured the ohmeage between P1-P2 which gives me 0.1   = a coil
There is NO interaction between P1 or P2 to any of the other Pins of this transformer.

Between P3-P4 gives me 352 ohms = a coil
Between P4-P5 gives me 330 ohms = a coil

Now heres the "extra" "bit" I measure between P5 and P3 and get 0.9 to  1.0 ohms
But, I expected to see across my multimeter about 706 ohms or close to that, instead I got 0.9 - 1.0 ohms.
The question is WHY?

This is confirmed on ALL 7 transformers.
Has anyone else discovered their Kodak transformers configured like this?

There is a problem though, to my understanding, the High Voltage would appear between Pins 3 and P5 it looks like a centertap is assoceated on P4, but why can I measure almost 0 resistance between P3 and P5? and how does this transformer still manage to have an output when there is seen an almost short circuit between P3 and P5?



I have spent literally hours browsing the net looking for the "pin outs" information on these transformers but it appears there is nothing on them or it is very well hidden.

Can someone else please confirm if the number of coils on these Kodak Transformers, are as I seem to have found.


I have a theory on the reason why their might be a "extra" coil between P3 and P5, is it a "control" coil, does it dampen or quench a spark so only one spark is alowed to exit the transformer, I don't know.
Is it to tie the two 355 ohm coils in parallel?
If the item between P3 and P5 was to go OC, then it would in effect double the output.
That might explain why some people have noticed a huge increase in brightness before their CFL stopped working and the transformer was burnt out. 


jim