Joule Thief

[Pardon]

@all,  has anyone attempted winding ferrite bars instead? ...toroids are a pain to wind.
Also, isn't the idea of having a pickup coil to capture voltages that would normally be soaked up by the collector - i mean, placing the pickup coil between the two primaries, or in some equivalent manner be like buffering the flux collapse?

I have but only one. it's 1/4 inch dia by 1-3/8 long. the 1st winding(power coil) equals the length of the bar about 50 turns. and insulated from the bar. the 2ND winding also insulated from the 1st winding is 15 to 20 turns spaced out for the length of the bar(trigger coil). the secondary is insulated from the 2ND coil and wound end to end and back plus a few turns back to the other side. so i have 3 wires out each side. the first 2 coils need a cross over 1 wire from each side to light an led (normal JT wiring)

i did not test it with a normal JT ckt. but here is what i get Bat voltage no load 1.04 v Base = 0.75 before resistor and cap Base = -0.43 v after res and cap. the collector =0.75. collector after a diode 3.47v. the secondary rectified =+7.65 v with led and +9.23 with out led in place.

also when this ckt is powered off the led stays lit for over 1 minute but it's very very dim

[TheNOP]

@all,  has anyone attempted winding ferrite bars instead? ...toroids are a pain to wind.

yes.
they also work, are they better ?, i can't say.
what i know is toroids are better all around compaire to El core, inculding work at higher frequencies.

ferrite bars are normaly only use as inductors but my flash unit is using one for its auto transformer.

Also, isn't the idea of having a pickup coil to capture voltages that would normally be soaked up by the collector - i mean, placing the pickup coil between the two primaries, or in some equivalent manner be like buffering the flux collapse?

there are a lots of reasons to separate the jt coils.
the first is Lenz's law of induction.
an other is that they are, in a way, working against each other.
by spreading the coils around the toroid there are less chances of blind spots

sometime i am wondering how a 1/x ratio would work.
1 being the number of turns of the base coil and x the number of turns to the collector coils.
theoricaly this should lower the voltage picked up, by induction from the collector coil, by the base coils.



B.T.W.
@all
what IST is playing with is called Litz wire.
Litz wire is often used in the windings of high-frequency transformers.
it increase their efficiency by lowering both skin effect and proximity effect.



@Mk1
i have already played with litz wire, at school.

each individual wire are affected by the core current in the same manner, even if they are twisted, they are as if they were separated coils.
that mean that i already know the outcome of one of the test i was to make.
it increase the efficiency at high frequencies.
i will still do that test and post the results as promised tho.

the whole world only uses half it but ... it AINT NEW .... LOL

i agree with you, but there are good reasons for this, technical, and monetary.

[innovation_station]

@jeanna

naw im just lazy ...  it will have 2 windings ... 

i have been through a alot in the last few weeks

lets say my mind aint on my work ....  it was 2 years ago .... 

now its just getting BORING....

ist!

gotta have a life too...

i have been saying this SAME THING  for soooooooo looooooonnnnnggggggg



perhaps way back in LOTR THRED...   

looked for help all over .... all i herd was yea right sure it works ...  then some big people come to see me TELL ME I GOT NOTHING ... 

AND I SAY

NO YOUR WRONG AND YOU DO NOT UNDERSTAND WHAT IM SHOWING YOU ....   THEN TOOOOOO CHEEP TO BUY ME   A FEW SUPER CAPS .....

I THINK THEY JUST DID NOT WANT ME TO PROVE THEM WRONG 


YET 1 MORE TIME .....

ist!


simple solution for the wires ...  in my winding

put diodes in pairs ...  solder 2 to each wire lol  your done match em up with a meter 

it does not need to be difficult..

i guess i will assemble the diodes this coil gets 120 diodes all 800v 3 amp ... i may be able to cut back on them ... tooo  ...  it is what ever i desire for output and runtime ...  it is a BALANCEING ACT

AND NOW WE ARE BACK TO RUSSEL BALANCED RYTHEMIC INTERCHANGE...     

[TheNOP]

@jonnydavro,
I missed your post before. Thanks for making that youtube vid. It is very clear.
And thanks for the replication.

@Jadaro,
Who knows what it means. I know the amount without the light lit is what the transistor takes. I don't understand why a short anywhere is necessary to describe this. [I think it is tuning]  also,
The transistor is using the amount going through the base wether or not any thing is across the C,E. Plus there is nothing at all connected to the toroid secondary winding when it is not being used to turn on a light..... I don't think electronics has an explanation for this.

it does   

http://en.wikipedia.org/wiki/Transformer

Winding resistance dominates load losses, whereas hysteresis and eddy currents losses contribute to over 99% of the no-load loss. The no-load loss can be significant, meaning that even an idle transformer constitutes a drain on an electrical supply.

that mean that the loss is greater without a load.

[jeanna]

it does   

that mean that the loss is greater without a load.

And the loss is the amps draw? so, the amps draw is greater without the load?

hmm.

thanks. There is no way in the world I would have been able to put that together to mean this.

jeanna