Joule Thief

[Thaelin]

@ Free:
   I just scored 4 of the cameras and all of them have the aaa board.
I feel that they no longer use the aa. The resistor you could not read is
a 58 megohm. The one on the bottom marked 749 is actually a diode and
not the one you need to jumper. The one with two readings is a 16K ohm
with the other  one a 16ohm. 

thay

[jeanna]

@Thaelin,
@Free,

Well Thay and Free, This is precisely the reason I set my goal to turn on a fluoro tube by using a hand wound toroid. I did not want to be dependent on the make up of this manufactured product whose design was for a different use.

So, a bunch of us have now been able to light fluoro tubes using hand wound toroids. We are getting closer to a formula that anyone could use to do this. (another goal of mine is to make the instructions easy and clear so anyone with the desire can make one herself. )(  )

I will jump back in in another day or so.
I am still enjoying my accomplishment.

Keep at it, and always have fun!

jeanna

[jeanna]

what I mean:



                        AC from JT
                        |                | /
                        +-----|<----| |---+
                        |                | \    |
   Relay coil      ||(                        |
parallel with JT ||(                        |
                     ||(                        |
                     ||(                        |
                        |                        |
                        |     \ |               |
                        +---| |--->|------+
                        |     / |
                        |
                        |AC from JT


I remember this from an older Internet source awhile back, ...
..., were thought experiments to replicate and improve on this circuit immediately above.
NOTE:
The precise circuit, I recall, had the caps paralleled on either side of the relay coil, but were also presented as I show them here---oppositely wired.  I did it this way for ease of drawing.

The Relay coil could also be the JT transformer itself
...

My question is:
Is there any limit to the number of these that can be added to the JT/relay coil?  Does Lenz' Law come into play with this tactic?

--Lee

I keep thinking you are drawing this.
Are you?

If you are, this is the reason I want to begin a AC from the JT thread. I am getting closer to doing it. 

I want to explore the question you pose.
Our house wiring is set up in a way like this and my surprise
2 tier circuit was operating like this with different potentials at different areas.

I wasn't answering you because I thought you were/are wanting to make it into DC, but just in case you are not...

jeanna

[TheNOP]

@Xee2
Before replying, I researched.

Using resistors on the transistors base is a current/voltage limiting device so the transistor Base dosent get over driven by a strong signal. If the resistors are all commoned at the sourse, tells me it's to keep all transistors in sync. They all switch on and off together.

I have paralled 4 X 2n3055 transistors in my second adjustable power supply which I used for 20 years. A LM317 (adjustable transistor) output was sent to the bases of all four 2n3055 transistors.

Connecting load sharing resistors can be on the Collectors or the Emitters, it is usually the emittors.
Generally people follow the below circuit.

adding resistors at the transistro's emiters is the way to limit current.
but..., is it what we want to do ?
for me, it is not the way i want to limit it.

the way i would try it is: a trim pot on each base + one potentiometer connected to all the trim pots.
once the trim pots are correctly set, all transistors will work equaly.

[stprue]

@Stprue
That is a very tidy big toroid there, looks like it's been wrapped in gold leaf lol.

Thanks that is the wire I have had the most success with.