How ironic then that so far the avoidance (of my questions, repeatedly) has been all yours. When you're ready to drop the avoidance, we may continue.
I said 'in the range of Henries'. You have tried to portray this as an obsession with the number 6000, why, I cannot imagine, unless it be that you seek to prolong the argument while avoiding addressing the crux? When I say 'you need shunt capacitors larger than the nanofarad range to make a significant impact on 100 Hz ripple' in this context, do you dispute that?
Now stop jerking my chain.
Now stop jerking my chain.
Nope, no reason to dispute that but I can't for the life of me see why nF range capacitors would be at all relevant here when the smallest filter cap I've specified is between 4 and 6 orders of magnitude larger (mF range vs nF) than that, and those are to be paralleled.
Methinks you're yanking my chain here.
I have done some more reading, and I have just decided to go ahead and build from this schematic.
If it doesn't do what I want it to do, I will adjust and alter it until it does do what I want it to do. The oscilloscope won't lie, and I will learn as I go.
Thanks to everyone on here that contributed something useful.
If it doesn't do what I want it to do, I will adjust and alter it until it does do what I want it to do. The oscilloscope won't lie, and I will learn as I go.
Thanks to everyone on here that contributed something useful.
Attachments
Isn't that almost identical to the one you showed us before? It still appears to contain the same mistakes. I wonder exactly what you have been reading? Certainly not our advice here.
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That would indeed be a correct reading. So what's the relevance of nF range caps in this context please?
Hi,
There are CMC choke designed for that purpose but I normally see them placed in the AC section and mostly before the transformer. What is the difference when using 2 separate chokes between caps after regulation (CLC filter) on both positive rail and ground vs just one choke on the positive rail for the CLC ?
Thanks
CMCs are current-cancelling, allowing a much higher value inductor (in common-mode) with a smaller core without saturation. Using separate inductors doesn't permit taking advantage of current-cancelling. Also they'll present the same inductance in normal (differential) mode as in common mode. A few hundred uH isn't going to make much of a dent in any CM noise - if you go checking the commercially available CMCs they tend to have inductances at least an order of magnitude higher, perhaps two to three orders higher.
CMCs are best used prior to the transformer as there the working currents are lower (assuming the trafo is the usual step down one).
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I am using a 330uh choke between the SMPS and the 6 x 4700uf smoothing caps see if it will attenuate sme switching noise.
Yes it will - the differential mode switching noise. However a SMPSU is also a source of CM noise which will tend to degrade SQ if no attention is paid to it.
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