AC from Joule Thief Secondary/pick-up

[jeanna]

Try the magnet one the one with the jt coil on one side
...
... helpfull with the altrez type design. try with the big one also if the magnet is too strong it will send the excess into space.

Oh this is one of those days that things break in my hand.

The MK.8 has the bifilar on one side and the MK1 type secondary starting and ending on the side opposite the primary. It gives good power with the right transistor.

The breadboard had that mk8 because last week I was tuning it to the 2N3055. and that was the reason the volts were lower than before. But I didn't realize what was going on until the pot collapsed and stopped being a resistor.

Maybe the magnet was too strong, and maybe there was never a dead spot anyway. So, you are thinking the magnet helps with the dead spot. It makes sense that it would.

Thanks. I will put this MK.8 together with a 2N3904 again. the "filter" core works better with them anyway.

I will use the 2N3055 for the chokes and the biggg ones. Then I will use the magnet and see.

Maybe I will dig out a hazens style and try the magnet on them too.

thanks,

jeanna

[nievesoliveras]

@Martin

Just so you know , usually we use 1.5 volts in the experiment done here , and we use a secondary one a regular jt , the same way you sue your transformer to make a inverter.

I bet with 12 v you already got over 200 watts .


Mark

I read somewhere that that circuit has a problem with the capacitors orientation.
The capacitor positive side goes to the collector instead of away from it.

Jesus

[resonanceman]

I  just finished  reading  the posts here

I  think  this  thread will lead to  some interesting stuff 



To me  lighting   things with  different  voltages   and  the  dead spots on  toroids both sound like  some kind of standing wave . 
If I am right  they would move  as the frequency  changes  .



Another thought 
I have always  believed  that   Radiant  energy  required high  voltage  and   high speeds (  a high rate  of change )   
I think  a MOT JT  can provide   both


gary

[xee2]

@ jeanna

JT outputs pulsed DC. If you want AC you should use a circuit like the following. Try it. I think you will like it. This is a standard flip-flop circuit that I modified for use with 1.5 volts and a toroid. I have not tested it but it should work. If you want to you can consider it a dual JT, although that would not be quite correct.

[jeanna]

Hi xee,
Thanks for this idea.

Yes, the jt does put out pulsed dc, but the secondary doesn't necessarily do that.

Actually, the reason I stick with the MK1 designs is because the secondary IS AC.
It is a very nice looking wave  -/\/\-, or at least a  -/^{^~}\/ - kind of thing
Sometimes if I can afford the voltage loss, a cap makes it look like a perfect sine wave.

I have not found another way to wind the secondary that gives this effect, so I stick with it.

However, because of the way it goes together,  it is really hard to add more turns to it.

That is why the possibility of adding to it with regular turns on top of the mk1 as another layer looked so good to me, yesterday.

I haven't been able to follow up on that, though.
Yesterday, the pot just collapsed into a non resistor.
This happens a lot with those pots. Very finiky.
Or, there is a possibility that they are arcing over the wiper somehow.

Have you ever tried to make a MK1 type pick up yourself?

thank you,
you always help a lot,

jeanna