Joule Thief 101

[poynt99]

Brad,

You expect to be cut some slack with your incorrectly depicted probe positions and scope traces, so I suggest you do the same for MH for assuming that energy has already been given to a resonant system. In fact a resonant system is resonant regardless if it is resonating or not.

[tinman]

It is definitely CH2 that is inverted, OR your coils are in opposite phase. Anyway, no big deal, but I would encourage you to note these things on your schematics, because as that scope shot was presented, it does not match up with the probes.
Sure, what is your definition of "impedance" of a transformer?

Let's start with that.

To Quote-the effective resistance of an electric circuit or component to alternating current, arising from the combined effects of ohmic resistance and reactance.

So as far as i can see,in order for the impedance to change,we either have to change the effective resistance,and/or the reactance.
To change the effective resistance,we either have to physically increase or decrease the turn amount of wire in the transformer,or increase or decrease the frequency at which the transformer operates.
In order to change the reactance,we either have to change the inductance value or the capacitance value-or both. This would show as a phase shift,where the current would be out of phase with the EMF that created it.

1-So how else can the impedance change?


Brad

[poynt99]

To Quote-the effective resistance of an electric circuit or component to alternating current, arising from the combined effects of ohmic resistance and reactance.

So as far as i can see,in order for the impedance to change,we either have to change the effective resistance,and/or the reactance.
To change the effective resistance,we either have to physically increase or decrease the turn amount of wire in the transformer,or increase or decrease the frequency at which the transformer operates.

Did you mean reactance, not resistance? Resistance doesn't change with frequency, but reactance does.

Is there any other way to increase or decrease (dynamically) the impedance of an air coil at a given frequency?

What kind of test could you conduct to play with the idea?

[wattsup]

You may wish to rethink your response. Clearly the glass resonates in a uniform fashion, and it does experience a maximum deformation point where it stops before being deformed in the other two adjacent quadrants.
https://www.youtube.com/watch?v=BE827gwnnk4

I am not treating it like a pulsed coil and it is not junk at all.  There are no harmonics.  It is directly related to coils, cores, and the like.  I already covered that in a posting.

@MH - @poynt99

You cannot trust your eyes. Saying it stops is specific. It's good to have a fast video capture like in the video but that video cannot show everything since resonance is a succession of micro movements. Why does everything have to be so cut and dry with you guys. IT STOPS. Wow. Ok then it stops. No it does not. As two sides move out, two sides move in and this does not mean anything stops. What you are inferring is at one point that complete wine glass STOPS. No. Impossible. There will always be a part of it in movement. Once it breaks, the broken pieces even move. Just because when two sides move out, of course for it to then move back it has to change direction and during that micro second the outgoing does not stop, it just moves in. THERE IS NO STOP. Move out, move out, move out, move in. It moved out just as fast as it moved in. If you want to call the last increment between the last move out and the first move in as a stop, that's, your business but during that time there are so many other places on the glass that are moving to accommodate that move. There is no stop, cigarette break, recess or any other delay. Maybe a coffee break. As fast as it moved out it moved back and during that time there are other movements in the glass. The glass does not stop. It was resonating even before they started the test. I told you this the first time. Everything resonates to everything especially instruments that are prone to physical resonance  like a wine glass. What's the point in resonating if you have to stop. You may as well say marching stops. Making a U turn stops. No it does not. There is a whole wine glass there and not just the rim. Also, did the sound influence ever stop? So why should the wine glass. Oh yeh, then use that sound and blast a coil and see if it resonates. There is no relation there. Physical influences and our coils don't play the same tune. And the audible tones of a pulsed coil is not resonance so do not go there. Now can I go play with the others.

wattsup

[Magluvin]

@MH - @poynt99

You cannot trust your eyes. Saying it stops is specific. It's good to have a fast video capture like in the video but that video cannot show everything since resonance is a succession of micro movements. Why does everything have to be so cut and dry with you guys. IT STOPS. Wow. Ok then it stops. No it does not. As two sides move out, two sides move in and this does not mean anything stops. What you are inferring is at one point that complete wine glass STOPS. No. Impossible. There will always be a part of it in movement. Once it breaks, the broken pieces even move. Just because when two sides move out, of course for it to then move back it has to change direction and during that micro second the outgoing does not stop, it just moves in. THERE IS NO STOP. Move out, move out, move out, move in. It moved out just as fast as it moved in. If you want to call the last increment between the last move out and the first move in as a stop, that's, your business but during that time there are so many other places on the glass that are moving to accommodate that move. There is no stop, cigarette break, recess or any other delay. Maybe a coffee break. As fast as it moved out it moved back and during that time there are other movements in the glass. The glass does not stop. It was resonating even before they started the test. I told you this the first time. Everything resonates to everything especially instruments that are prone to physical resonance  like a wine glass. What's the point in resonating if you have to stop. You may as well say marching stops. Making a U turn stops. No it does not. There is a whole wine glass there and not just the rim. Also, did the sound influence ever stop? So why should the wine glass. Oh yeh, then use that sound and blast a coil and see if it resonates. There is no relation there. Physical influences and our coils don't play the same tune. And the audible tones of a pulsed coil is not resonance so do not go there. Now can I go play with the others.

wattsup

I have to agree. The glass is never in a perfect standing shape while ringing. It will always have a distorted shape as compared to if it had 'no input at all' shape and form. And even if it looks and sounds like it has stopped when the ringing can no longer be seen nor heard, it probably rings all the time due to ambient random noises/vibrations, at levels that would need equipment to detect and measure.

Mags