When do objects Resonate?

triggernum5

Joined May 4, 2008
216
And charge responds when subjected to the potential energy difference.. Seriously, its exactly analogous to a gravitational 'field'..
Its all about 'potential'.. if no electron gets to tap into that field then the 'potential' for an electron to fit nicely into your equations just wasn't realized..
 

Wendy

Joined Mar 24, 2008
21,906
I can understand a lot of your confusion, beginners in electronics and RF are taught a lot of concepts that aren't really accurate, but get them on the road to learning. Later these concepts are tweaked to more accurate models. Just be aware of the two schools of thought.

For example, AM is a really easy to understand explanation, easy to work with, and works in most circuit designs. You can understand how a crystal radio works with it. It isn't until you get into carrier waves and sidebands that you realize the flaws of the first model. In real life they don't matter though, it is a lot like Newtonian physics and Einsteinian, both models work within limits.

They only reason I mention this is don't assume you have a complete understanding, you can have a paragram shift later. The subject is complex enough there is a building process involved during learning.
 

triggernum5

Joined May 4, 2008
216
There is a pretty hefty thread in here called "a treastise on voltage" iirc.. Its a big collaboration/argument regarding the definition/concept of voltage..
 

Thread Starter

Mathematics!

Joined Jul 21, 2008
1,036
Ok I figured it out apparently books that say potiential difference (voltage) is the work per charge only applies when we have charges involved. But the more general definition should be taught as
integral of E * ds. Then the definition can be made independent of charge.
So voltage only depends on the electric field and the displacment, not really a charge.

Anyway the book never really stressed this fact.

Sorry We mathematicians are picky with definition kinds of things.

Anyway where can you get inductors because at radioshack they only sell capacitor's. They also sell chokes but I don't really understand the point of these.

If they don't sell inductors then can I just use a coil of wire?
Or will this be to imprecise? Because I cann't make that simple radio don't have a Germ... diode. I do have other diodes though.
 

beenthere

Joined Apr 20, 2004
15,819
Check with Jameco (jameco.com) and see if they don't still have 1N34's.

The Shack will have RF chokes that are intended to eliminate RF from a power lead. They are inductors, but not useful in your application. Wish I still had the 1924 Pop Mechanics that described building a crystal radio. The inductor was wound on an oatmeal carton. The tuning cap was made from the foil from a pack of Luckies.

A coil of wire will work just fine. I can't give the several sites, but coil winding formulas are available online.

If you want to get a kit, American Science & Surplus has a crystal kit for about $12.
 

studiot

Joined Nov 9, 2007
4,998
You are still trying to make matters too complicated.

To achieve your transmission you do not need any diodes, silicon, thermionic or germanium or any other sort.

You simply need to turn the supply on and off rapidly to the tank circuit. This is all a morse key does.

The pulses of continuous wave will be radiated by your antenna/inductor and received by its twin. I would suggest 200 to 250 turns of enamelled copper wire around a wooden frame 12 inches square.

You can experiment with capacitors in the 1 nanofarad range.
 
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Hi,

In order for a system to resonate one must put energy into it.
what you must understand is the timing. The timing must be right.
inducing energy into a system could damp the system's frequency if the proper timing is not taking into consideration.

Let me know if I'm wrong.

Myidismine,
 

Ratch

Joined Mar 20, 2007
1,070
Mathematics!

Ok I figured it out apparently books that say potiential difference (voltage) is the work per charge only applies when we have charges involved. But the more general definition should be taught as
integral of E * ds. Then the definition can be made independent of charge.
So voltage only depends on the electric field and the displacment, not really a charge.
I have always advocated in this forum that voltage is the energy density of the charge. It takes energy to gather together or remove electrons as is done in a capacitor when it is energized. The closer one gathers a given number of electrons together, the more energy it takes, the higher the energy density of the charge, and the higher the voltage. This energy is stored in a electrostatic field which you quantified by the equation above. I don't know how to obtain a electrostatic field without a imbalance of charge.

Resonance is a condition that occurs when two energy storage elements take in energy and release it in opposite phase to each other. For instance, in a electrical circuit, if the capacitance energy intake/release in in opposite phase to the inductive storage element intake/release, then resonance occurs, and the amplitude is limited only by the resistance encountered by the transfer.

Ratch
 

davebee

Joined Oct 22, 2008
540
I haven't seen any mention of Q in this thread, which makes a big difference in the response of a system to incoming energy.

Any system will vibrate due to being excited by external energy of any frequency, whether the incoming energy is at the system's resonant frequency or not, but the vibrations near resonance will be greater. How much greater depends on the Q of the system.

The higher the Q, the less the loss in the system, the less it will respond to frequencies away from its resonant frequency and the greater it's response at or very near resonance.

An LC circuit with a lower Q will have a much broader frequency response but lower value of peak response to an incoming EM wave. You want this for an AM receiver because the modulation energy is in the sidebands, off the center frequency. So to make an AM receiver you want the Q of the LC circuits broad enough to respond strongly for the AM sidebands, a couple of kHz off center frequcncy, but narrow enough to give low response to adjacent stations, 10 or 20 kHz away.

Also, an oscillating LC system will be surrounded by local E and M fields that grow and shrink in strength which are different from the travelling EM wave. The difference is that the local E and M waves ordinarily return their energy to the LC circuit (if it isn't absorbed by some external system), where the EM wave does not. At short distances, one LC oscillator can excite another from the local E and M waves similar to how a transformer transmits energy from one coil to another via magnetic fields.

Mathematically the local E and M waves are out of phase in time, where the electric and magnetic fields of the travelling EM wave are in phase with respect to time (but the direction of their vectors are at right angles to each other.)
 

Bernard

Joined Aug 7, 2008
5,285
And you all thought that this thread would just crawl back in its hole. Back in 1934, Dr Royal Rife experimented with resonance in liveng organisms, and developed a frequency machine which ,when tuned to proper frequency would destroy a virus or bacteria, or cure certain cancers. You can now buy your own for about $2,495. I do not have one.
 

Bernard

Joined Aug 7, 2008
5,285
Just quoting what I read. " I love the Pro Wave and it's healing my husband of Bladder and Prostate cancer. His PSA keeps coming down." Sarah K No web site, toll free 888 563 5335. When you buy yours let us know if it works. I'll bet the WEB can caugh up some info on Dr. Dife.
 

Dolph

Joined Nov 26, 2013
1
Resonance is a (reflection) back onto itself, a tuned oscillation, a Pumped wave, as a Laser is reflected inward back onto itself,by a shiny mirrored surface, to create spontaneous emission, this laser energy must be held for a time, called pinning the charge,Capacitors seperate and pin charges momentarily, for Pico/Nano/? seconds, this amplifies the energy until the laser end mirrors are overcome by the greater energy.So it is a reflection back onto itself,but a tuned frequency.Which must be combined with an addition to the currents frequency, of 1/4 wave, to make up for those losses,so say 60Hz +15Hz=75 Hz. So you must reflect back on to itself,but not with destructive Harmonics,but tuned harmonics of the exact same frequency so they amplify, they add to the Fundamental frequencies energy, in Tune exactly,with the (exact same frequency) because only an exact frequency will work.So use a wave guide tuned to your frequency you want,use a shiny reflective mirrored surface inside the waveguide, to reflect your frequency/energy back onto itself inside of this tuned waveguide, then to your device/circuit?. Pin the charge, with Maxwell Ultra Capacitors,(UC's) establish a sustained resonance,by adding to the currents frequency 1/4 wavelength.You are basically causing a cascading/tunneling beam, of electrons.(This is what you want to create energy correct?), work with this until you discover this sustained condition. Dolph
 

WBahn

Joined Mar 31, 2012
24,853
Was this such a compelling point that you really had to dredge up a five year old thread to make it?

In all fairness, I imagine that you didn't realize how old the thread was when you stumbled across it -- and most of us have made that mistake -- though I think the forum now makes you jump through an extra hoop to respond to a thread older than a certain date (or that hasn't been responded to for more than a certain amount of time).

In the original post, the "asker of many innane questions" asked if distance mattered for things that resonate. Posts #31 and #31 show that this thread resonated over at least a two month period. You've just given evidence that it comes back to haunt us even after an additional five years!

So I guess distance in time doesn't matter! :eek: :D
 
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