LC supply filter

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Imagine a simple LC supply filter, say 10H and 100µF. If both the inductor and the capacitor were divided into two equal parts, with both LCs in series we get a superior filter with double the slope for the same cost (I'm aware that two caps will probably be more expensive than one, but bear with me). Now, instead of winding that 10H choke, I could put two 5H inductors on the same core. If I switch the direction of current on the second winding, the magnetization of the core should be in sum zero, since both currents are the same. That means, I can build the choke without a gap and get higher inductance out of the choke for the same cost, or use less iron to produce the same choke, while also getting double the slope for the filter in both cases.

Just thinking out loud. Is there any mistake in my thinking? I hear free lunches are rare in electronics :D.
 
+1; by using the flux induced by each half of the winding to cancel each other out - you've just discovered the method employed to minimise inductance of wirewound resistors and similar - and with no net inductance, no energy storage.


Nice try! (and don't feel chastised - we all have comparable 'brilliant' ideas from time to time that don't survive the light of day...)
 
Why do you assume equal currents in the inductors? The DC currents are equal of course, but the ripple currents not because there is a capacitor at the tap - or at least that's the impression I get when reading the opening post. (I don't think it will work well anyway, because the inductive device is a transformer rather than two separate inductors.)
 
Why do you assume equal currents in the inductors? The DC currents are equal of course, but the ripple currents not because there is a capacitor at the tap - or at least that's the impression I get when reading the opening post. (I don't think it will work well anyway, because the inductive device is a transformer rather than two separate inductors.)
I had the same thought: DC currents are compensated, but AC ones aren't.
This does not mean that it could be made to work (easily): the first L section will see a large AC voltage, which will be impressed on the second.
This means that the middle capacitor will probably be critical, and will need to be tuned.

In the end, I think the optimum implementation would end up as a notch filter, but for energy storage, something else would be needed in addition.
Harmonics would also need to be addressed.

If the scheme can work in some way, it has probably been patented in the '20s or so, because all these alleys have been explored, and people of that time were no less clever than we are
 
Why do you assume equal currents in the inductors? The DC currents are equal of course, but the ripple currents not because there is a capacitor at the tap - or at least that's the impression I get when reading the opening post. (I don't think it will work well anyway, because the inductive device is a transformer rather than two separate inductors.)


You might be referring to coupled inductors and ripple current steering.


https://www.st.com/content/ccc/reso...df/jcr:content/translations/en.CD00268621.pdf

Ripple steering?


Extron's Patented Ripple Steering Class D Audio Amplifier Technology | Extron



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