Joule Thief

[innovation_station]

a question if i may    lol 

lets ask what a cap across the gap will do lol

on the input side...  when the feild colapses what will it do first .... FILL THE CAP ?!?!?!?!?!?!

LOL

lets recap when you break the flow it returns first to where you broke it ..  hence where we are taping it so

on the input side...  cap it where we put the led to cut way back on inputted engery ... 


next you need a place to pull out from ....  a secondary ...  hummm 

ist!

[xee2]

@ gadgetmall

Thanks for the correction. I'm sorry I didn't read better. Experiment always trumps theory.  I would think the low current is because of the 20K resistor.

EDIT: Did you change the resistor values on the diagram?  With a 20K pot the capacitor can have an effect  It seems to me that originally the resistor was 20K.

[Pirate88179]

OK I measured the total ma draw in series with the battery . 2.85ma   divide by  4 = 0.71 ma per led  . I used 4 windings of 20  all in series center tapped at 40 total 80 turns normal JT no secondary .. It is a Large Green Toroid . and yea i believe from what i have read that this is a step forward . it is still going . i wont touch it until it is dead but that could be a very long time as the voltage is still .90 full bright and 2.84 now . i guess its a little cold in here so the components are just a bit different . WOW . 90 Still .The only mod to the normal jt circuit that made it draw less and put out more was the little non polarized cap marked 680 ,across the variable resistor . ok the variable resistor has three legs . i use wiper and on end for adjustments and put the cap across the resistor part the two outside legs . Does this make sense ?

I have just reread in my electronics books about this.  Three legs is not a variable resistor, it is a potentiometer.  As you can see on my latest video from a few days ago, I too used a pot as a VR.  This is done, according to my books, by using the wiper and one of the other legs.  If you use one, the resistance goes up as you turn CCW.  If you use the other leg, the resistance goes down as you turn CCW.  (and visa versa)  Variable resistors have only 2 legs but Radio Shack did not have any so I used a pot.  If I am incorrect about this, please, someone let me know.  This is what my books say however.

@ All:

Thanks to everyone involved here on reaching the 200 page mark!!!!!!!  Over 2,000 posts and we are still going.  I still have to go back and catch up from a few pages back.  My old cat (15 years) is very sick and I have been working with the vet and taking care of her most of the day.  This is indeed a landmark and I appreciate that it was noticed by those that posted about it.  Once again, to all of the experimenters and posters.......a real big THANK YOU.  You all are great!!


Bil

[jeanna]

repost

@Bill,
I am sorry to hear about your cat. Take care of her.

@Gadgetmail and All,
I just plunked a cap .1uf into the place you did,(I think). The lights went way dim. Since I have used all my whites for the array, I am using yellows. In fact it may be easier to tell since they lose brightness more visibly than the whites.

I also rigged up a way to check rectified voltage a little easier and more reliably. It also went down a lot with the cap. one on the um Collector and the other at the far end of the 820R resistor.

I do think it must be the size and 4o times bifilar that makes it so good, but we'll see. Anyway the cap hurt the production on the secondaries of my jt.

jeanna

[sparks]

@mk1   

  Force felt at afar effect.  Tempic field response.