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curiouschris
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I was reading a very old article this morning about electrical theory, it was talking about the flow of current in a tank circuit otherwise known as a tuned cct. (parallel LC cct).
A strange and disturbing thought struck me. I know *how* a tank cct oscillates. but I don't have the foggiest *why* a tank cct oscillates.
Let me explain further.
The How...
If you charge a capacitor and then attach it to an inductor such that the cct is in parallel, the charge in the capacitor will rush through the inductor creating a magnetic field around the inductor until such time as the capacitor is discharged. when the current stops flowing due to the discharged capacitor, the flux collapses creating a current which then charges the capacitor in the opposite polarity, once the flux has collapsed the capacitor starts to discharge and the cycle repeats.
In a cct with a high Q factor this can continue for quite a while. We will ignore losses due to resistance for now please.
My electronics is a bit rusty but I am pretty sure at the basic level the above describes the process or the HOW a LC circuit resonates.
Now the question is *Why* does it resonate?
Even in a high Q cct, shouldn't the capacitor only discharge to 50% of its charge, where upon the magnetic flux which now contains the equivalent amount of energy as the remaining charge in the capacitor prevent further current flow?
It sort of indicates that electrons are massive and once in motion don't want to stop even when an equal and opposite force is applied.
Perhaps the opposite.
The magnetic field is extraordinarily easy to create, even a small current can support all the potential energy it contains.
But in this case as soon as the flux starts to collapse and the capacitor accepts even a tiny amount of charge it should then prevent the flux from collapsing any further.
I hope I have made myself and my quandary clear.
Can anyone tell me *Why* such a cct can resonate. in fact why does anything resonate, a tuning fork for example?
CC
A strange and disturbing thought struck me. I know *how* a tank cct oscillates. but I don't have the foggiest *why* a tank cct oscillates.
Let me explain further.
The How...
If you charge a capacitor and then attach it to an inductor such that the cct is in parallel, the charge in the capacitor will rush through the inductor creating a magnetic field around the inductor until such time as the capacitor is discharged. when the current stops flowing due to the discharged capacitor, the flux collapses creating a current which then charges the capacitor in the opposite polarity, once the flux has collapsed the capacitor starts to discharge and the cycle repeats.
In a cct with a high Q factor this can continue for quite a while. We will ignore losses due to resistance for now please.
My electronics is a bit rusty but I am pretty sure at the basic level the above describes the process or the HOW a LC circuit resonates.
Now the question is *Why* does it resonate?
Even in a high Q cct, shouldn't the capacitor only discharge to 50% of its charge, where upon the magnetic flux which now contains the equivalent amount of energy as the remaining charge in the capacitor prevent further current flow?
It sort of indicates that electrons are massive and once in motion don't want to stop even when an equal and opposite force is applied.
Perhaps the opposite.
The magnetic field is extraordinarily easy to create, even a small current can support all the potential energy it contains.
But in this case as soon as the flux starts to collapse and the capacitor accepts even a tiny amount of charge it should then prevent the flux from collapsing any further.
I hope I have made myself and my quandary clear.
Can anyone tell me *Why* such a cct can resonate. in fact why does anything resonate, a tuning fork for example?
CC