Sm0ky2:

You are still stuck on talking about resonance and giving examples of resonance.  You are saying that "I don't get it" but the problem is that your examples don't even apply to a Joule Thief.

The JT transformer is not even being excited with a continuous signal.  It sees a voltage source across its terminals when the transistor is on and then it sees nothing, no excitation, when the transistor is off.

I will use "inductor" instead of "transformer" for the discussion below.

Transistor on:  The inductor is being energized.  Current flow through the inductor starts at zero and starts to increase linearly.  During this phase battery energy is being stored in the inductor and the LED is off.

Transistor switches off:  Now you have a circuit like this:   Battery -> inductor -> LED.    Here the inductor "looks like another battery in series" but that's a simple easy-to-grasp way of stating it.  To be more accurate the inductor acts like a discharging current source with a finite amount of energy.   The real circuit is this:   Battery -> current source -> LED.

The battery and the inductor current source will discharge into the LED until the inductor runs out of energy.  Because it's a current source, you can just as easily discharge into 20 LEDs.  When there are 20 LEDs instead of one LED, the inductor will discharge more quickly.

That's the basic cycle for a Joule Thief.  It has nothing to do with the self-resonance of the inductor.  Since the stimulation for the inductor is <voltage clamp> <nothing> <voltage clamp> <nothing>  there is no real mechanism for self-resonance.

A Joule Thief is nothing more than a mechanism for energizing an inductor and discharging that inductor through an LED.   You could do exactly the same thing with a 555 timer output controlling the switching of the transistor via the base input.

Pulse-type switching and discharging are not the same thing as self-resonance at all.

If you tried to stimulate the inductor with <voltage clamp> <nothing> <voltage clamp> <nothing> stimulation at the self-resonant frequency of the inductor then the inductor would not discharge nice fat chunks of stored energy through the LED.  Instead, the inductor would be in epileptic seizure territory and just self-resonate due to the voltage clamp pinging from the switching transistor.  There would be no orderly mechanism where the inductor is given sufficient time to discharge trough the LED.   In addition, the actual method for maintaining the operating frequency for the JT requires that the inductor undergo regular energize-discharge cycles.

So all of your links and stuff about self-resonance do not apply.   You are feigning trying to "teach" me here when you are the person that needs to be taught.  That is a huge mistake and I have seen it before.  You need to seriously reevaluate your self-perceived notion of how much you understand about electronics, and how much you understand the operation of a Joule Thief circuit.

MileHigh

Sm0ky2:

You are still stuck on talking about resonance and giving examples of resonance.  You are saying that "I don't get it" but the problem is that your examples don't even apply to a Joule Thief.

The JT transformer is not even being excited with a continuous signal.  It sees a voltage source across its terminals when the transistor is on and then it sees nothing, no excitation, when the transistor is off.

I will use "inductor" instead of "transformer" for the discussion below.

Transistor on:  The inductor is being energized.  Current flow through the inductor starts at zero and starts to increase linearly.  During this phase battery energy is being stored in the inductor and the LED is off.

Transistor switches off:  Now you have a circuit like this:   Battery -> inductor -> LED.    Here the inductor "looks like another battery in series" but that's a simple easy-to-grasp way of stating it.  To be more accurate the inductor acts like a discharging current source with a finite amount of energy.   The real circuit is this:   Battery -> current source -> LED.

The battery and the inductor current source will discharge into the LED until the inductor runs out of energy.  Because it's a current source, you can just as easily discharge into 20 LEDs.  When there are 20 LEDs instead of one LED, the inductor will discharge more quickly.

That's the basic cycle for a Joule Thief.  It has nothing to do with the self-resonance of the inductor.  Since the stimulation for the inductor is <voltage clamp> <nothing> <voltage clamp> <nothing>  there is no real mechanism for self-resonance.

A Joule Thief is nothing more than a mechanism for energizing an inductor and discharging that inductor through an LED.   You could do exactly the same thing with a 555 timer output controlling the switching of the transistor via the base input.

Pulse-type switching and discharging are not the same thing as self-resonance at all.

If you tried to stimulate the inductor with <voltage clamp> <nothing> <voltage clamp> <nothing> stimulation at the self-resonant frequency of the inductor then the inductor would not discharge nice fat chunks of stored energy through the LED.  Instead, the inductor would be in epileptic seizure territory and just self-resonate due to the voltage clamp pinging from the switching transistor.  There would be no orderly mechanism where the inductor is given sufficient time to discharge trough the LED.   In addition, the actual method for maintaining the operating frequency for the JT requires that the inductor undergo regular energize-discharge cycles.

So all of your links and stuff about self-resonance do not apply.   You are feigning trying to "teach" me here when you are the person that needs to be taught.  That is a huge mistake and I have seen it before.  You need to seriously reevaluate your self-perceived notion of how much you understand about electronics, and how much you understand the operation of a Joule Thief circuit.

MileHigh

Also, it is the duty cycle and frequency that allows us to "see" the led being "on" when indeed it is only flashing on/off faster than the eye can detect.  Learning this did not bother me as I was after light, and being able to light a large amount of leds on a "dead" battery is useful to me.  We know they are not really "on" but, I just want the light so I don't care. (It looks always on to the human eye.)

Nothing magic or overunity at all with the JT.  It is, however, a very useful circuit in many applications and that I like about it.  In a way, now that I know what I know, it is cheating a bit, but, if the outcome is what is desired then, it works.  Lighting leds with high frequency/high voltage is a great way to get a lot of light with little power drain. (This is more about the advanced JT circuits not the basic ones)

Still, no magic.  No O.U.

At least, not yet, ha ha.

Hey, you never know...right? (Just kidding)

Bill

 I wouldn't pay too much attention to MileHigh.. He is only a distractor and usually give litmus tests to befuddle and never answers anyones requests to answer questions posed to him. Just go to his profile and check his posts.. You will see what his methods are and they are proven by those massive posts. He is a distractor meant to frustrate anyone trying to do any outside of the box thinking. Why because he has an ego the size of Russia and just as filled with gas... Some of it pointless gas.. Just ignore him like I and many others do. He is a self appointed police for this community driven by his many many years of in the box thinking. Only doing what he was told and paid to do, never going outside of that little world and never having an original thought in his whole life.


 Take this for what you will he doesn't mater one bit but to the others who "police" this forum. You got to ask yourself who is paying him now?

You are a classic glazed-eyed forum-paranoid guy with no understanding of electronics.  I am just explaining the simple truth behind a simple circuit to help someone.

What you are basically saying to Sm0ky2 is "Don't learn the truth about this simple circuit, drink my Kool-Aid instead."

You should be ashamed of yourself and at the same time it is very sad.

Bear in mind the Steven Mark devices ran on a single capacitor, charged only once to start the device.
and it operated the transistor for weeks, sometimes months before the power dissipated.

There went what little credibility you had left, out the window.

As for the rest of your statements about JTs and resonance etc ... I refute thee thusly:

I attached an annotated series of waveforms for a Joule Thief.

The red arrow shows the moment the transistor switches off.  You can see how the current that was flowing through the inductor the moment before the transistor switches off becomes the current flowing through the LED the moment after the the transistor switches off.   Then the whole process starts all over again when the inductor is fully discharged.

Do you see any "resonance" in that timing diagram?  The answer is that you don't, you are looking at a switching circuit, a.k.a. a "pulse circuit" and there is no resonance at play.

Yes I can see that by your waveform, its not sin   <---- fix that before you continue

There went what little credibility you had left, out the window.

As for the rest of your statements about JTs and resonance etc ... I refute thee thusly:

TK, do you remember the beginning of the TPU epidemic.....
 Why do you think the JT got so much attention to begin with? 
  Back before it even had an LED in the circuit....
people were trying to say it was pulling current from the wires inside the walls through inductive coupling or some crap...

all it does is oscillate back and forth from the inductor to the cap.
the LED added a load, which drained the cap, thus a battery was implemented.
Then it was discovered that you can use a "dead" battery and it still works....

They got less and less efficient over time, as more and more people began making them, and ignoring the operating conditions SM had placed on the circuit.

@ MarkE,TK,and MH.
Insted of saying rubbish,how would we go about building a resonant JT,or makeing my circuit opperate as it dose,but with a much higher power output?.Maybe a small cap in series with a diode across the collector/base?.

It wouldn't look much like a JT.  It would take multiple transistors.