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In the Forum: Audio Discussions
In the Thread: Correcting Filters and the quantum theory.
Post Subject: What about memristors?Posted by hagtech on: 9/7/2008
My first answer would be "3". But then I think some more...
Is "A" really a shunt? Where is the power dissipated? Certainly not in the capacitor. The signal is burned off (converted to heat) in the series element! In circuit "B" it is the shunt element that burns off the power above 1kHz.
Why is an inductor better? It has permeability issues (akin to permittivity in a dielectric), magnetic hysteresis, interwinding capacitance, etc.
When investigating questions like this I often take things to the extreme. For example, what if the input signal was a kilovolt? Now you think about volts per meter and insulation and arcing through the atmosphere and humidity and electrode spacing of the capacitor and heat dissipation in the resistor. What if the frequency was 1GHz? What if the frequency was 0.1Hz? That coil starts to get pretty big. What practical issues show up at the extremes? Now re-apply them to the question at hand. All the things one has to worry about at the extremes are still existent at 1 volt and 1kHz, just to a different degree. But it does get you to think about theoretical limitations.
The other thing is that you can never appropriately ask such a question in isolation. The circuitry before and after this filter changes the reality. Often, the answer is more dependent upon the driving or receiving circuits than anything else.
So I guess I stick with "3" for now.
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