Joule Thief

[conradelektro]

To Jeanna, Pirate88179, Gyulasun !

Great, your very detailed comments catapult me forward. Thank you very much, I appreciate your advice. A steep learning curve looms in front of me.

This software for amateur radio (Gyulasun posted it,  http://www.dl5swb.de/html/software_for_amateur_radio.htm ) is very handy.

I have about six different toroids and some other Ferrite cores to experiment with. All goes forward so fast that I run low on LEDs, I am waiting for a bunch of blue and white LEDs to arrive.

Jeanna's light will soon glow near Vienna (Austria) and the multitudes will flock to it, or something like that  .

Greetings, Conrad

[gyulasun]

Gyula:

I had not seen that before.  Thanks for posting it.  The only thing I do not understand is that he said he wanted low permeability for his toroids and yet, I believe, most of us have had our best results with high perm.

I do not pretend to understand everything about the JT circuit, far from it.  I just can't figure out why he wants low perm?  Can you or anyone explain this?

Thanks,

Bill

Hi Bill,

My best guess on you question is Conrad connects his "low frequency" oscillation with his high permeability core and thinks using a lower perm core will increase the frequency. Somehow he thinks his 15kHz freq is a low value and that it is maybe a drawback.  I think this is the simple reason.  Now that he got pleanty of good answers, he will be ok sure.   

Thanks,  Gyula

[Pirate88179]

Gyula:

I think you may have misunderstood my post.  I was talking about the guy in the blog link that you posted wanting low perm. not Conrad.  Sorry if I was not clear.

But yes, I agree that the good folks here will share all of what they have learned to help Conrad, and anyone, work with these fascinating circuits.

Conrad:

When you get your lights shinning in Austria, post some photos.  I'll bet that will be a beautiful site.

Bill

[forest]

Could someone propose JT circuit which may replace neon sign transformer ? I mean a circuit which can produce a few kV output from low volts input (for example 9v battery) using toroid core with frequency not less then 20khz (30-50khz would be better) AND WITH additional pulsing t. The idea is to have kV DC pulsing output (using diodes) with variable and adjustable pulsing frequency set by POT on primary.
A nice small circuit able to charge HV capacitor.
Is that possible ?

[resonanceman]

Could someone propose JT circuit which may replace neon sign transformer ? I mean a circuit which can produce a few kV output from low volts input (for example 9v battery) using toroid core with frequency not less then 20khz (30-50khz would be better) AND WITH additional pulsing t. The idea is to have kV DC pulsing output (using diodes) with variable and adjustable pulsing frequency set by POT on primary.
A nice small circuit able to charge HV capacitor.
Is that possible ?

Forest

When I first started playing with 12V input for  JTs  I tried using a MOT ( microwave oven transformer ) for a JT coil

I have no  idea how high  the voltage was but it was up there .
When I smelled smoke  I shut  it down.
I later found that where ever my  alligator clip leads crossed it had arked through the insulation.

Another way I have melted the insulation  is by running  the  output  of  a fairly strong  JT through a automotive ignition coil.
( in series with the load )
My first thoughts about  this  when I  trid it ........ this  thing is just plain mean ......... I  burnt out a 90 LED array  and  fried a DMM in seconds.........so be careful

gary