Joule Thief

[electricme]

@Altrez,

Can you explain to me how to measure half of the leg?
Thank you!

-Altrez

Just take the tape measure and go from ankle to knee, (half a leg) 

jim

[gadgetmall]

@Altrez,
Just take the tape measure and go from ankle to knee, (half a leg) 

jim

Jim .My Messaging is messed up here and it wont let me send  but thank you for your kind and gentle words and Spirit . You are a True friend Indeed . I also Enjoy your Work and Especially all th eneat Junk you find . Sounds like me  Good day Mate . It night fall here and approaching 12 midnight . Must get some rest now . Happy Experimenting . !!
Gadget

[electricme]

@ the Gadget

Albert, I am glad you are back on your feet mate, it's no fun being crook.
Your little girl is an excellent achiever, you can be very proud of her.

Nice you are back to posting again, we all missed you.

jim

[jeanna]

I am sorry then !

But you did not get better results ? even with more turns and checking the pot?

Mark

More turns happened to be on the other coil the base instead of the collector.  and it caught me by surprise.

I am interested to see what xee thinks about this.

Well, to be honest I only use the pot when I have a good enough candidate or need to push it more.

I start with about 4 plain resistors to get me within range. It is much faster for me. I have a tedium problem and repeatedly pulling out the battery and then checking the ohm meter then putting back the battery then turning the pot etc, is too tedious for me to start with, so I plunk in a 33, then a 580, then a 1k then a 2k2.  If it won't start I have a range of caps to add. This is quick and gives me an overview of the range of the toroid. Then I can get close with the pot.

It is a learning style. I need to see the overview first then I can dive in. Others must do every detail first and build an overview from it. Just a different style.

Then this is a strange toroid , its look like it like it slow . Low hz.

Well, it is very large. Stprue took a pic of this toroid next to his hand a couple of weeks ago.

Anyway the voltage came right up when I put the 14T on the base and the 3 or 4T on the collector. very backwards. I guess no rules apply, still.

@Gadget, I am glad you are feeling more calm. welcome back.

jeanna

[Mk1]

Well, to be honest I only use the pot when I have a good enough candidate or need to push it more.

I start with about 4 plain resistors to get me within range. It is much faster for me. I have a tedium problem and repeatedly pulling out the battery and then checking the ohm meter then putting back the battery then turning the pot etc, is too tedious for me to start with, so I plunk in a 33, then a 580, then a 1k then a 2k2.  If it won't start I have a range of caps to add. This is quick and gives me an overview of the range of the toroid. Then I can get close with the pot.

It is a learning style. I need to see the overview first then I can dive in. Others must do every detail first and build an overview from it. Just a different style.



jeanna

Jeanna

That way of testing would not work for me , since the sweet spot is not that big , there is no way to tell what is the best .

I agree that checking for the pot resistance value takes longer , but not always needed , unless you find something worth mentioning , and if you like me use one plastic battery holder they are sometimes hard to get the battery in and out , and i agree its a waist of time , for that i usually use the alligator clip wire.

On what i have seen the sweet spot change depending on the jt turns , on that spot you get usually get up to 30 % more volts , at a very specific spot i would say there is less then 5 % margin , so getting i idea from 4 resistor , i do have problems with that , since there is no real way to know if you improve or not . Maybe the precision pot with 25 turn is overkill for now 1 turn should do.

I tough you had more concrete reason for not doing it like i do , other then to long , to that i can only say taking time is not bad if you get result .


Also i forgot to mention i also use 2 meter one with 2 wires on the probe so i can connect to the board easily check the pot value .

Mark

Now the big box question , is the sweet spot at the same freq with every different jt coil turns , or dose it change.

Why is that important , because if the freq stay the same the toroid is the dictating factor for power and the freq , if it changes then its the coil resonance that we are looking for , even better would be to have both at the same freq , in a ultimate jt design.

Mark