Joule Thief

[AbbaRue]

@electricme
You  need to rub that large metal ring with a strong magnet and make sure it doesn't stay magnetized.
If it stays magnetized it won't work as a transformer core.

@gadgetmall 
After seeing your post #4234  with the picture of that magnet coil configuration.
It reminds me of Tom Beardens MEG.
Then I took another look at the MEG. and couldn't help but think about replacing the 2 control coils with JT windings.
I also came up with the idea of using 2 microwave fan motors to make a MEG.
Just hacksaw the section flat were the rotor is inserted on one of the motors and remove that section completely from the other.
The stack of magnets can be inserted were the rotor used to be and JT windings can be placed around the cores.
Probably would want a higher power transistor for the JT circuit though.
And who says the JT has to run on a 1.5 volt battery.
Add more windings and it can use a much higher voltage battery.
8 times the windings should work with a 12 volt battery.

@All
I just think it might be time for some to take the next step with the JT and try building a power supply to run larger things.
And the MEG may be the way to go.      Mk1's coil setups have many characteristics of a MEG.  Just need the magnets.

@MK1
Have you tried placing a stack of neo. mags. across the inside of your toroidals  were you have the 180 deg. split.
IF you do that it should function just like a MEG.  Take another look at the MEG. 

http://www.cheniere.org/megstatus.htm

The only difference between your toroidals and the MEG is the MEG uses 2 U shape cores, and a toroidal is 2 half circles.
Or did you leave that gap in your toroidal setups just for this very purpose down the road?
Theoretically the toroidal transformer should work even better.  (It's an easy Mod for anyone to try)

[AbbaRue]

@MK1
Sorry I missed your post #974 were you said you were building a small MEG. (found it today)

http://www.overunity.com/index.php?topic=6123.970

I kept coming across posts were you mentioned using a magnet but it never sunk in that you were using it to make a small MEG.   
This thread is so large it's very easy to miss a page with key points on it.
Summing things up how well is it working?

[resonanceman]

Scienceman

As far as I can see no radiant energy  has been shown  from a JT .............yet
It looks like it is  a combination  of  capturing   the spikes caused by the magnetic  field collapsing  and   transformer action .






Does  anyone  have  a link for a larger toroid that works well ?

I want  make  a bigger  JT ........not  toilet sized yet  .........but  bigger  than  a normal  toroid .


gary

[jeanna]

A long time ago (january, I think  ) I said I wanted to do the fuji ckt but in a hand wound way.

So, I looked hard at that fuji ckt this morning and decided to wind a little trial toroid in a slightly different way. I had a hint of this thought yesterday but this is a bit different.

I made the primary with 5T and 8T. but I did it by centering the 2 primary wires and winding 2 1/2 in each direction, then continuing with only one of them out in both directions. I could have made it perfectly even, but I see I didn't quite.

charcoal 1/2 toroid
2N3904 transistor
799ohm base resistor
1.35v battery
primary centered 5T,8T
secondary 18T

As a bjt the led is very bright. and it draws
34.1mA

I added 18 turns secondary just to see. and by now, these results are not too surprising.
with
1 led 24.2mA
2 led 23.6mA
3 led 22.4mA

The point of this was the secondary multiplication so I rectified the volts and saw
11.25volts

Then I turned on my new scope with freshly charged batteries.
The timer marks are now set and the way I read it, this scope is telling me that I have a very nice sine wave. I mean it is even. pointed but even and the center mark for this one is in the center of the curve. the MK1 and 2 had more dramatic sharp spiky curves but they were all above or all below the center line.
I have no idea if this is significant, but it seems it to me.

The scope says I have not 11volts but from peak to peak 750mV    |/\/\/\/\/\/\|18 full curves in 2usec.

Anybody have an idea? I am still trying to make the dmm rectified volts and the strobe measurement of the volts agree. I have not been able to do this yet in 2 days.

It is possible that the symbol looks like peak to peak but is rms. I am still learning. Is there anyone who can say that this looks like a possibility? I mean would 750 mV rms be equivalent to 11.5 rectified volts?

So, I got 2 things from this little test.

1- there is a nice shape ac produced when you center the primary wires, even if you have different length wires in the primary.
2- there is good amplification from primary to secondary, but the bridge and scope do not agree how much - by a lot.

thank you

jeanna

[xee2]

@ jeanna

It would seem that you have a 100:1 scope probe. On a good scope with and a good probe the display will automatically adjust for this. But not all scopes and probes do this. Most likely you are getting 75 volts peak to peak which would be about 37 volts DC out of a full wave rectifier for a perfect sine wave. Try using the probe on a 1.5 volt battery and see what shows up on the display - don't forget to zero the scope first - short out probe and adjust vertical trace position to 0 volts. It sounds like you got a good scope for the price.