Joule Thief

[stprue]

@ Jeanna or all

Have you wound a Mk1 x2 on a toroid of this size?  If so what were your results?

[jeanna]

@ jeanna

Your data seems to indicate that the frequency is increased as the base capacitance is increased. Yet you said a while ago that you could see the spacing between the pulses increasing as the capacitance increased. Thus I would expect that the frequency would decrease as the capacitance increases. Can you check this out?

Did I say that?

It varies.
This is what I am talking about when I mean it has to be in range to increase the frequency.
If the cap is too large for the job, the frequency and the volts become lower than without any cap.

See reply #5421 the first 2 lines.
In fact I have a 3rd line not published.
103cap 80KHz 0.44V and then changed to 101cap and got 200KHz, 3.21V

Later - it was with more turns on the secondary - the same overly large cap that reduced the freq and volts on 1,2,and 3 turns, became very helpful in making the frequency faster with 12 turns..
I sure don't understand it, but I think what I saw before is consistent with yesterday's table.

Not long after that post, I think I was describing the effect of the capacitor on the shape of the wave. So, the frequency would be the same, but the shape would be different.
Like this:

__|__|__|__|__ and __/\_/\_/\_/\_ both have the same frequency. They both have 4 peaks in 14 spaces, but when the cap is too big for the job it looks like the one on the left.

I thought you had described this and I brought it up as a confirmation. But the frequency itself would not be different.

thank you. I will check further to see.

@All,

I think it needs to be done in an order.

I adjust the frequency of the toroid with the bifilar by changing the number of turns on the primary bifilar and plugging this into the bjt ckt, and checking this on the scope looking at a secondary of any description. This is just to see a directional change if any with the number of turns on the primary bifilar. (Like what MK1 does, only easier)

Unlike what MK1 was doing, I am going for the highest frequency and nevermind the volts for this part.

So, now the toroid is able to vibrate at its maximum. I can change the base resistor to anything and add as many secondary turns I want to for higher volts.

Now, is when I am also adding these caps across the base resistor and seeing an additional result.  (But only when the cap is in range.)

I am sure a formula is lurking around here somewhere. 
(more data are needed for this formula to present itself! so please, everyone can help.!!!)

OK I am off to wind that second side and test.
I will check in every once in a while too!

thank you,
jeanna

[jeanna]

@ Jeanna or all

Have you wound a Mk1 x2 on a toroid of this size?  If so what were your results?

No.
I was planning to get that toroid from allelectronics too, but I have managed to put off the purchase for 2 1/2 weeks so far!  (some other people like shopping).

You asked MK1 a couple of questions I could answer too.
You can get 1 or 2 crosses per turn on the going back down part. If you just go up then turn and go down you should only be able to get 1 cross. This you can put anywhere, but since the inside is tighter than the outside it is natural to put it there on the inside of the toroid.

More secondary turns = more volts; roughly speaking.

You max out your turns when you run out of room. BUT, this is all too new and still very experimental. I think slayer007 had 7 or 8 rows of turns, so maybe it really does not matter?

Just start. A lot of this will clear itself up when you have put your hands into it.

have fun,

jeanna

[stprue]

@Jeanna

So with the jt part of the coil I could make...say...the two 3 turn crosses / across the coil and my wind ups/ and downs I need to max out?  Is this right or am I just confusing what the different windings are called?

[xee2]

@ jeanna

_ and __/\_/\_/\_/\_ both have the same frequency. They both have 4 peaks in 14 spaces

I wish I had a scope. So maybe the decrease in current when the base capacitor is added is because the spikes get narrower. The narrower spikes would have less energy than the wide spikes and thus use less current. I was assuming the decrease in current was because there was a longer time between the spikes with the added capacitance. Any more data you can collect on this would be appreciated. Thanks for what you have done already.