my susceptance/reactance is modelled by a chain ABCD matrix
-1 -jB
0 -1my susceptance/reactance is modelled by a chain ABCD matrix
-1 -jB
0 -1I explained it badly.
Just stick a 4ohm resistor across the cap and watch the resonant frequency. john
-- Posted via a free Usenet account from http://www.teranews.com
-- That\'s cheating, I think. The OP specified that the resistance was in series with a series LC.
On 2 Mar 2007 02:24:24 -0800, "Phil Newman"
--- Not according to your original post:
In a filter I've designed, I have a series LC with additional reactance, X, which gives a transmission zero in the filter.
How can I absorb the reactance into either the L or the C or both?
In a simple series LC, the reactance of the product at resonant frequency is 0, so
jX (reactance) = jwL - j/wC = 0
from which you get
w^2 = 1/LC
however, with the additional reactance (which is frequency invariant
- i.e constant)
jX = X + jwL - j/wC = 0
the value of X, w, L and C are known.
Notice that you stated that the additional reactance is frequency invariant. That is nonsensical and an impossibility since the reactance is the imaginary part of the impedance and _is_ what changes with frequency since the real part can't.
Then, from your third post, we have:
If i put in my frequency invariant susceptance/reactance which isn't a resistor, it is just constant reactance, then this shifts the resonant freqency from w = 1 to w = 1.15 (eg)
where you seem to still not understand that a frequency invariant susceptance or reactance _must_ be a resistance.
---
--- Oh well...
---
--- Bingo!!! Now, if the resistance doesn't change the resonant frequency it must be because changing the resistance isn't changing the reactance, changing the L or the C is. So, if something _is_ changing the resonance it must be reactance, and of that you've only got two types; inductive and capacitive, neither of which is frequency invariant.
-- JF
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