MH's ideal coil and voltage question

[MileHigh]

Brad:

Another select morsel from Wikipedia with the mad hope that you will get it and the insane hope that you will simply admit that you get it.

Note that they discuss the two meanings for resonance.  Have a good brain fry over that.

https://en.wikipedia.org/wiki/RLC_circuit

Natural frequency

The resonance frequency is defined in terms of the impedance presented to a driving source. It is still possible for the circuit to carry on oscillating (for a time) after the driving source has been removed or it is subjected to a step in voltage (including a step down to zero). This is similar to the way that a tuning fork will carry on ringing after it has been struck, and the effect is often called ringing. This effect is the peak natural resonance frequency of the circuit and in general is not exactly the same as the driven resonance frequency, although the two will usually be quite close to each other. Various terms are used by different authors to distinguish the two, but resonance frequency unqualified usually means the driven resonance frequency. The driven frequency may be called the undamped resonance frequency or undamped natural frequency and the peak frequency may be called the damped resonance frequency or the damped natural frequency. The reason for this terminology is that the driven resonance frequency in a series or parallel resonant circuit has the value[1]

        ω  = 1 / Sqrt(L*C)

This is exactly the same as the resonance frequency of an LC circuit, that is, one with no resistor present. The resonant frequency for an RLC circuit is the same as a circuit in which there is no damping, hence undamped resonance frequency. The peak resonance frequency, on the other hand, depends on the value of the resistor and is described as the damped resonant frequency. A highly damped circuit will fail to resonate at all when not driven. A circuit with a value of resistor that causes it to be just on the edge of ringing is called critically damped. Either side of critically damped are described as underdamped (ringing happens) and overdamped (ringing is suppressed).

No spaghetti here.

[MileHigh]

Brad:

Revenge of the wine glass.  The attached pdf discusses how to determine the natural resonant frequency for a wine glass.  It's the real thing, and it's full of integrals.  However, if you were a keener and tried to follow it, it will become readily apparent that a wine glass is just another version of a bloody LC resonator.

Remember I said I did a 20-minute search to back up the answers to the two wine glass questions?

MileHigh

[verpies]

What's more interesting than the philosophical issue whether a resonance can exist without an unbalance of energy in the resonating/resonant system, is why the Mythbusters could not break the wine glass with a single tone, but could do it with two tones?

[allcanadian]

@MH

For the tune pipe in your Wikibooks link, for starters, there is no resonant frequency at all, there is only a cycle time.  In addition the cycle time is dependent on the length of the tune pipe, just like the cycle time for an echo depends on how far you are away from the wall that the sound waves bounce off of.  From the link, "the goal is to have the diverging section create a returning rarefaction wave and the converging section create a [/size]returning pressure wave[/size]."  So there is no modelling of this in any kind of "resonant LC device" way.[/size]

My assumption was that the tuned pipe was not necessarily a "one shot" device and that once the exhaust port closed the returning pressure wave would partially reflect off the closing port back to the open end. We could model the pipe like a transmission line with one open end. An impulse from our exhaust port/HV coil travels down the line and part of the impulse reflects back towards the source which created it. However if the exhaust port closes or the HV coil is detached from it's source then we should see another reflection.


I don't know if the tuned pipe pressure wave was designed to oscillate within the chamber or simply reflect from the open end back to the exhaust port like a one shot device. If I designed a tuned pipe I would want the pressure wave to oscillate (more than one reflection) and do so covering a wide rpm range.[/size]


AC

[tinman]

Brad:

Another select morsel from Wikipedia with the mad hope that you will get it and the insane hope that you will simply admit that you get it.

Note that they discuss the two meanings for resonance.  Have a good brain fry over that.

https://en.wikipedia.org/wiki/RLC_circuit

Natural frequency

The resonance frequency is defined in terms of the impedance presented to a driving source. It is still possible for the circuit to carry on oscillating (for a time) after the driving source has been removed or it is subjected to a step in voltage (including a step down to zero). This is similar to the way that a tuning fork will carry on ringing after it has been struck, and the effect is often called ringing. This effect is the peak natural resonance frequency of the circuit and in general is not exactly the same as the driven resonance frequency, although the two will usually be quite close to each other. Various terms are used by different authors to distinguish the two, but resonance frequency unqualified usually means the driven resonance frequency. The driven frequency may be called the undamped resonance frequency or undamped natural frequency and the peak frequency may be called the damped resonance frequency or the damped natural frequency. The reason for this terminology is that the driven resonance frequency in a series or parallel resonant circuit has the value[1]

        ω  = 1 / Sqrt(L*C)

This is exactly the same as the resonance frequency of an LC circuit, that is, one with no resistor present. The resonant frequency for an RLC circuit is the same as a circuit in which there is no damping, hence undamped resonance frequency. The peak resonance frequency, on the other hand, depends on the value of the resistor and is described as the damped resonant frequency. A highly damped circuit will fail to resonate at all when not driven. A circuit with a value of resistor that causes it to be just on the edge of ringing is called critically damped. Either side of critically damped are described as underdamped (ringing happens) and overdamped (ringing is suppressed).

No spaghetti here.

Well thats fantastic MH,you posted a post on damped and undamped resonant/Natural frequencies.
Please point out where it says anything about when such systems are resonating,or when they are just oscillating at there resonant frequency.

I see this-->The resonance frequency is defined in terms of the impedance presented to a driving source.
Other than that,your post means didly squat about resonating.
nice try,but not good enough,as you are going over ground that we already know.

Yes--there is still spaghetti MH,and lots of it.


Brad