Joule Thief

[stprue]

stprue

I am not sure of the details of what you are doing, but if the capacitor is on the pickup coil output you may be putting too much voltage into it. I was originally using a capacitor rated at 500 volts after the diode and it was damaged when my voltage got up to 1000 volts.

I have a 400v .01uf cap after a 1000v @1amp bridge rectifier.  This 1 cap added to the circuit adds about 400 additional volts.  I am not sure why but have an idea.  My more pertinent question is about the voltage threshold and apparent discharge.  This leads me to believe that caps in the right places on this JT circuit are tuning components. Anyway I'm not really sure.  My recent pic's are the same setup as my smaller coil I'm referring to, let me know what you think because there is something going on here.

Thanks you very much...Stew

[jeanna]

@Jeanna

Have you tried a cap right off the output voltage of a bridge rectifier, or maxcaps off the input?  One this I have noticed with one of my smaller coils was that as it was increasing in voltage after I turned it on, it seemed to hit a threshold where it would all of a sudden go to 0v and then begin to climb back up until it hit that same threshold voltage.  This makes me think that the capacitors are another way to tune a specific JT and crucial at that.  I'm not really sure why they seemed to be discharging suddenly and honestly only with that coil (goldmine 5 for 1$$) but I wanted to know if you have run into this before or could explain it to me.

Hi stprue,

The short answer is yes, I have collected all that in a cap (from a fuji cam) thru a bridge. That was before I got the scope, though.

I cannot explain it to you, but I have been working for days now getting the tesla lectures in a readable form for others to read.
I just added 2 1/2 pages to the ac jt thread next door.

The subject is about how to make different ac effects from 5 different circuit configs. The last one is how to turn it back into dc.
Just when you do read it, remember that the sparks are replaced in out circuits by the transistor. oh happiness! 

Maybe it will explain it to you.
What you are seeing makes sense to me after reading this lecture a few times. (there is much more of it) and, even though I cannot explain it to you, it may get through to you as it did me??

BTW, in that diagram he was intending to have the experimenter use all 6 circuits at the same time.

It may take a few more long days, but I plan to upload that lecture as a pdf here on ou.

In any case, you can copy all the words and the pics and save them on your computer for more relaxed study.

I hope this helps a bit.

jeanna

I see xee gave a real answer. good stuff.

[xee2]

**** WARNING ****

I was trying to post new results, but it looks like this site has been hacked again. I went to add attachment and got a pop-up add instead. So there may be other hidden viruses on the site now.




EDIT: It seems to only happen once in a while so I will try again.

[xee2]

Test results with 400 turn pickup coil. Battery was almost dead so that may be why the battery capacitor helped so much.

[xee2]

@ Mk1

@all

More info !
Tesla bifilar coil!

There is also some talk about the circuit part in red , now used in his new Bedini/jt circuit.

I know you know a lot about coils. So I tried to find a manufacturer for this product, but could not. But the image you posted does mention pulses, so I suspect that this is meant to operate using short duration DC pulses. In which case it would double the voltage. You probably knew this but it is not obvious to me from looking at the image. But, that is the only way I can see that this could be a real product.