Joule Thief

[xee2]

@ Jeanna

Congratulations, you now have a way of detecting very small differences in the transformer performance. I am not sure, but I suspect that maybe the differences you are seeing are due to the larger wire increasing the capacitive coupling between the turns of the two windings used for the basic JT. This is equivalent to adding a small capacitance between the base and collector of the transistor which changes the transistor performance slightly.  Just as a test, try holding your finger on the windings and see if that decreases the brightness of the LEDs. Your finger will increase the capacitive coupling between the windings. If this is the reason for the differences you are seeing, then by making the secondary winding a separate coil around the toroid instead of winding it over the top of the other windings should reduce this effect.

EDIT: It would be interesting to see if the LEDs are brighter when the two coils used for the basic JT are separated as Mk1 does than when the two coils are wrapped bifilar together as is normally done. The added capacitance between the base and collector will be less when the two coils are not close together (but the inductive coupling will be the same). I always use separated coils but I never actually did this test.

[Mk1]

@jeanna

Thanks !

[nievesoliveras]

@all

There have been a lot of new advances in our knowledge here.
I hope that our knowledge be solid and true. The next generation will be the ones that will enjoy our efforts. Our children.
I have seen repercussions of our experiments here all over the world.
So let us do our best effort to do something positive for the ones that will stay on this world.

Jesus

[MrMag]

Jenna,

When I get out to the shop, I will try it. One question, did you happen to try wrapping maybe 5 or 6 strands of the small wire once around the torroid and connect the ends together? I don't think it will increase the current to the LED's but it should increase the voltage giving you a higher wattage to the LED's. I think I am going to try this too.

Tim

[innovation_station]

great work just on time of course  ...

lol

im drawing up my compleat ring  so all can bee seen ..  it is to scale as well 


the coils pictured in my coil are not compleate yet the secondaries are what i have laying around ...  they will be re wound when the proper gage is found ... 

im gonna cut my tubes to a certan length .. and my welding rods to  6"

will atempt this today ..

ist