Joule Thief 101

[MileHigh]

Sorry to hear, but that is Karma, mirror was working!
But very good that you did find it out, is there a cure, are you're kids affected!

Strength, and fast healing progress to you, we need you're old one back!!

Hugz, Johan

If you had used that picture and compared it with another member, let's say Ramset as an example, you would have been shamed and destroyed by the other members of this forum and told to apologize.  I would have said it myself.

I am a member of this forum just like any other member and your behaviour was disgusting.  You should apologize to me and to every member of this forum for your sick and disgusting behaviour.

[MileHigh]

No Webby, I am dead-on accurate.

The guitar string is in resonance with the air while it is making a sound, the air being the outside force that is taking the internal stored energy from the string, change the direction of energy flow and the air can add energy back into the string.

So if the string is oscillating at its preferred frequency with no external interaction it is only oscillating.

Well, thanks for showing the world that you have been bluffing your way through this.  Your statement about the guitar string and the air being in resonance is ridiculous.

Can you apply the wine glass questions to the example of the skyscrapers or the Tacoma Narrows bridge and answer them successfully?  I somehow doubt it.

[tinman]

Brad:

Yes I know, there is a level of subtlety there in what you are linking to that escapes you.  All of those links use the most readily understandable way of describing resonance to effectively get the idea across, that being that "resonance" is the response of a resonant system to an external stimulating frequency.  It is the way to get the concept across to someone that has never used the word before and does not understand what in means.  In fact, it is obvious that "resonance" can indeed mean just that, "the increased response of a resonant system to an external stimulating frequency at the resonant frequency."

However, like I already told you, words can have more than just one meaning, and latching onto one meaning of a word like you are doing, and then trying to claim or pretend that other related definitions of the word are invalid is a totally ridiculous thing to do.  And that's what you are doing right now, and it is clearly not the first time you have attempted to do something like this.

Let's take a look at your first quote:

Definition of Resonance - "The increase in amplitude of oscillation of an electric or mechanical system exposed to a periodic force whose frequency is equal or very close to the natural undamped frequency of the system."

Now let's break it down and simplify it and look into it a bit more deeply.

>>> The increase in amplitude of oscillation of a mechanical system exposed to a periodic force whose frequency is equal or very close to the natural undamped frequency of the system.

Now let's substitute "whose frequency is equal or very close to the natural undamped frequency" for "resonant frequency."

>>> The increase in amplitude of oscillation of a mechanical system exposed to a periodic force at the resonant frequency of the system.

Let's substitute "increase in amplitude of oscillation" for "resonating."

>>> The resonating of a mechanical system exposed to a periodic force at the resonant frequency of the system.

We know that the "mechanical system" is in fact a "resonator."

>>>  The resonating of a resonator exposed to a periodic force at the resonant frequency of the system.

The resonator exhibits the property of resonance.  We can say that "resonance" is the process where a resonator resonates at the resonant frequency.  For example you can say, "the resonator is in a state or resonance" when it is vibrating at the resonant frequency.

So, "resonance" also means "a resonator resonating at the resonant frequency."

Also, "being in a state of resonance" means "a resonator resonating at the resonant frequency."

Notice that there is a no "exposed to a periodic force" anymore.  You don't need it.

"Resonance" is a word that describes a mechanical or electrical system resonating at the resonant frequency.  A classic example is the wine glass.  You strike it once and then it is a resonant system that is resonating at the resonant frequency.  You can say "self-resonant frequency" or "resonant frequency" they are synonymous.

A stand-alone wine glass can be a resonator resonating at the resonant frequency - it is in a state of resonance.

So your clinging onto the first definition that you see for "resonance" and pretending that there are no other definitions of the word to "prove me wrong" is ridiculous.  It's just one more in a long long list of ridiculous statements that you have made in this thread.

MileHigh

Another failed attempt MH.
As the resonator(wine glass) will not gain or maintain maximum amplitude with just one strike,then it is not in a resonant state,it is in a state of oscillation,where the amplitude is decreasing,not increasing to reach it's resonant state.
Being in resonance is to maintain maximum amplitude at a minimum cost to the external force maintaining that resonance.

So it is not the first definition MH,it is the only definition.
You can try and twist things around ,to try and save face,but it is not going to happen,and you will not redefine terms to suit your need to be correct.

You show me your wine glass resonating without an external force acting upon it to maintain that state of resonance,and then i will believe you. Until then,stick with the laws written and defined within the books you preach daily.

Once again--resonance is not oscillation at a resonant frequency.

Brad

[tinman]

No Webby, I am dead-on accurate.

Well, thanks for showing the world that you have been bluffing your way through this.  Your statement about the guitar string and the air being in resonance is ridiculous.

Can you apply the wine glass questions to the example of the skyscrapers or the Tacoma Narrows bridge and answer them successfully?  I somehow doubt it.

The Tacoma Narrows bridge and skyscrapers oscillate due to aeroelastic flutter,the very same way the reed in a mouthpiece for something like a saxophone works.
In both cases,an outside force is needed in order to reach a maximum structural  terminal amplitude.
This situation cannot be directly related to the wine glass,as the input force is not a periodic force as such for the wine glass.

Oh look--the boy on the swing.

When a father pushes his kid on a swing, the motion of the swing has a natural frequency. If the swing comes back every 8 seconds, its natural frequency is 1/8 = 0,125 Hertz. Now if the father wants to maintain the motion of the swing, he has to push it each time the swing comes back to him, which means every 8 seconds. The force used by the father to push the swing every 8 seconds is the external force applied with a periodic frequency. If the father does not push the swing at the right moment (i.e. every 8 seconds), he will damp the motion and the swing will not go as high as the kid would wish. However if the external periodic frequency of the father matches the natural frequency of the swing, we get a resonance vibration. The resonance vibration will allow the kid to climb back and forth as high as he wishes with his swing.

Oscillation at the natural resonant frequency is not resonance.

Brad

[tinman]

No Webby, I am dead-on accurate.

Well, thanks for showing the world that you have been bluffing your way through this.  Your statement about the guitar string and the air being in resonance is ridiculous.

Have you lost your marbles MH.
That statement is absolutely correct.
How do you think one tuning fork can get another tuning fork, that has the same resonant frequency,resonating right along side it if the sound waves are not also vibrating at the same frequency,and at a maximum amplitude determined by the driving tuning fork (the outside force)?.

You really need to brush up on resonance MH.


Brad