Joule Thief

[resonanceman]

in fact the input voltage changes the frequency. period. When one of those 2 components goes up, the other goes down, I see it all the time.
end edit

Where do you want me to check the frequency of the primary?

Jeanna     

I don't think that it matters where it is checked .
Each pulse will  travel the entire circuit ..... I see no reason the frequency  should change at one part of the JT but not at another .   


If you have observed  with your scope  the  frequency  changing  because of  voltage changes ..... then   you have already  verified  my observations.

thanks




[/quote]

[jeanna]

OK, Gary, I do not need to repeat this test for you.

I found that when I did anything that raised the voltage the frequency would drop.
And the reverse, whenever I did something that increased the frequency the voltage dropped.

So, I first told the world when I was tuning the base resistor, when I increased the base resistor value the frequency in the pickup increased, and the voltage dropped.
Then I wound more turns on the toroid to increase the voltage, and it did. And, as the voltage increased, the frequency decreased.

Stick a magnet on a toroid.
The frequency jumps up and the voltage drops.
Sometimes I see some people notice this as an anomaly, but it isn't. It is a rule.

I checked this out a lot of times and ways.
There have been a couple of exceptions, but they were small and may have to do with resolution of the scope more than something else.

In the 2 tier circuit, it continues to happen, but in a complicated way.
Those secondaries are no longer working on a 'simple' single toroid. but the effect is almost 100% the same.

When I was watching professor Lewin teaching about or around this subject, I saw an equation a differential equation that addresses this. It was not the same circuit as ours, but there was the same reciprocal relationship of voltage to frequency.

Hmm, I just lost half this post...
One more thing.
One day I doubled the battery voltage going into th system. The frequency jumped up but the output voltage to the secondary did not.

I have a thought that this is a loss that can be caught, and used. Whenever one of these components rises I wonder if there is something to do to stop the other from falling, or to catch it as it falls.
It also seems to bolster my idea that frequency can take the place of amps, if it is tweaked right.

just some thoughts added to some definite observations.

jeanna

[Pirate88179]

@ Jeanna:

Some very good thoughts and observations there.

Bill

[resonanceman]

OK, Gary, I do not need to repeat this test for you.

I found that when I did anything that raised the voltage the frequency would drop.
And the reverse, whenever I did something that increased the frequency the voltage dropped.

So, I first told the world when I was tuning the base resistor, when I increased the base resistor value the frequency in the pickup increased, and the voltage dropped.
Then I wound more turns on the toroid to increase the voltage, and it did. And, as the voltage increased, the frequency decreased.

Stick a magnet on a toroid.
The frequency jumps up and the voltage drops.
Sometimes I see some people notice this as an anomaly, but it isn't. It is a rule.

I checked this out a lot of times and ways.
There have been a couple of exceptions, but they were small and may have to do with resolution of the scope more than something else.

In the 2 tier circuit, it continues to happen, but in a complicated way.
Those secondaries are no longer working on a 'simple' single toroid. but the effect is almost 100% the same.

When I was watching professor Lewin teaching about or around this subject, I saw an equation a differential equation that addresses this. It was not the same circuit as ours, but there was the same reciprocal relationship of voltage to frequency.

Hmm, I just lost half this post...
One more thing.
One day I doubled the battery voltage going into th system. The frequency jumped up but the output voltage to the secondary did not.

I have a thought that this is a loss that can be caught, and used. Whenever one of these components rises I wonder if there is something to do to stop the other from falling, or to catch it as it falls.
It also seems to bolster my idea that frequency can take the place of amps, if it is tweaked right.

just some thoughts added to some definite observations.

jeanna

Thanks for the  reply

I can see that  you have given this alot of thought.

I  have not  focused  on  frequency very much ......  I  was pretty sure that it was a  frequency shift that was causing my  self charging circuits to stop charging if  I left them alone for  more than a few hours .

Once I  get a scope  I will have a practical way to watch the frequency among other things .

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I have not  had much time  to work with my  bifilar  toroid   today
I did  try  one thing so far .   
I   I reversed  the  wires going  to the E and the base .
I had made the  mag wire   shorter  for lower  resistance for  the base .

Now  I  have  conected  the  iron  ( higher resistance ) wire to the base and  it is like a  different  toroid .
Before  I could not get  enough  power out of it to do anything  with  1 AA
It also  would not run without the  JT LED  in place .

Now  it lights brightly   with  1 AA  and  does not  change much  when I remove the  JT LED

The  voltage  across the LED array is  only 2 V more than  yesterday .......but the  LEDs are at least twice as bright ......



gary

[Pirate88179]

Gary:

Try E-bay for the scope.  A few months back I picked up my Tektronics 2213 dual channel 60 mgHz scope for $110.00 plus shipping.  This was the scope to have, so I am told, from back in the 80's and 90's for technicians and EE's.

It is obviously not battery powered but Jim helped me solve my little predicament with my EB by suggesting I use an extension cord (25') and clip my leads to it outside and then attach my probes to it inside.  Works very well for me.  Just a suggestion as these can be had for a decent price if you watch for them and get one from a good seller.

Bill