RLC

[jason]

Thanks Garth

My doubt is
" I wonder what physics that lies
behind the series LC tank to make the max current to flow to the rest
of oscillator circuit without keeping most current in the LC tank(like
in parallel)

"

Jason

 

[Lord Garth]

anything?

I'm trying to figure out how to explain it...

I think you see that in your series resonant LC the Xl and Xc cancel
leaving only the R term as the impedance of the LC combination.

There is no added R to the series resonant LC so we are left with
the ESR of the cap and the resistance of the coil wire. Both of these
are really low so Z is consequentially low. Since the series resonant LC
does not feed back to itself until the loop through the active component
is complete, the current will not (can not) circulate within itself, as it
is
not yet a complete circuit.

This is bit like asking why glass is transparent. The best answer seems
to be that there is no reason it shouldn't be.

 

[jason]

Hi Garth

Thank you so much
I learnt so much from you and other kind people up there
So that means for parallel LC , there is a existing loop within itself.
Therefore, it will keep the current in the parallel LC tank rather than
let it flow to the active circuit?

Thank you


Jason

 

[jason]

Hi Garth

Thank you so much
I learnt so much from you and other kind people up there
So that means for parallel LC , there is a existing loop within itself.
Therefore, it will keep the current in the parallel LC tank rather than
let it flow to the active circuit?

For parallel LC tank, the gain of the active circuit must be greater
than 1. Then the initial loop gain must be greater than
1(theoritically, in practical is at least 2)

For series LC tank, what is the condition, do you know?

Thank you


Jason

 

[jason]

Hi Garth

Thank you so much
I learnt so much from you and other kind people up there
So that means for parallel LC , there is a existing loop within itself.
Therefore, it will keep the current in the parallel LC tank rather than
let it flow to the active circuit?

For parallel LC tank, the gain of the active circuit must be greater
than 1. Then the initial loop gain must be greater than
1(theoritically, in practical is at least 2)

For series LC tank, what is the condition, do you know?

Thank you


Jason

 

[Lord Garth]

Hi Garth

Thank you so much
I learnt so much from you and other kind people up there
So that means for parallel LC , there is a existing loop within itself.
Therefore, it will keep the current in the parallel LC tank rather than
let it flow to the active circuit?

Yes, and it will decay over time due to losses within the components.

For parallel LC tank, the gain of the active circuit must be greater
than 1. Then the initial loop gain must be greater than
1(theoritically, in practical is at least 2)

For series LC tank, what is the condition, do you know?

Thank you

Sorry, I don't know this one but I would guess that a gain of 2 is
a practical minimum here as well.

 

[jason]

Thank you Garth
It is my honour to have learnt so much from you

Thanks a lot and wish you good luck

rgds and thanks
Jason

 

[Lord Garth]

Thank you Garth
It is my honour to have learnt so much from you

Thanks a lot and wish you good luck

rgds and thanks
Jason

You're welcome Jason, I hope you continue to study and in your own
time, help others as well...

Take care,

Jon

 

[jason]

Sure Garth(or Jon). I will do my best as a learner and help people who
is in need
Thank you so much


Jason

 

[Lord Garth]

Sure Garth(or Jon). I will do my best as a learner and help people who
is in need
Thank you so much


Jason

Great, keep up with your studies!
You are welcome