The effect of switching frequency on ferrite cores losses, f*Bpk and answer to riddle 

Thank you, Professor for sharing this intuitive way of looking at ferrites. I have been working on ferrites for over 25 years, yet I find your presentation very informative and purposeful. Thank you!

Hi Prof. Sam. As always your topic bring me at the end of the pesentation. Thank you.

Thank you so much.

Thanks Sir

Thanks！

Great information sir, I was wrong about core losses. I tried an isolated SMPS with EI ferrite core rated at 100kHz. But I switched it at a frequency of 25kHz thinking that a lower switching frequency should not be a problem. The core heated up so much that it fell apart by losing glue. Your video is of great help for me professor. From your video my other conclusion is that ferrite core doesn't care whether it's a sinusoidal signal or square wave. Because higher order harmonics makes no considerable harm to the core - from a core loss perspective? Is that correct?

Thank you for this very helpful video! If I may ask a question, please, wrt the equation in the slide shown in the 14 minute mark-- I've seen calculations of inductance (say in a boost converter) use the peak to peak current and ∆B value. Once the inductance has been worked out, ∆B is re calculated and divided by 2 to get the Bpk value to estimate loss from the manufacturer's graphs. Is this "divide by 2" approach applicable for inductors/ chokes as well as transformers?

Thank you for this knowledge sharing. I want to know about air-gap effects in flyback topology. How to counter it and it’s effects on cross regulations.

Thank you so much professor. Do you have any plan to teach DC DC converter topologies ?

Thank you for your videos on magnetics design, has helped me alot! I have a question that is not specific to this video, but rather about coupled inductor design. I am trying to compare the efficiency of a two phase buck converter using single inductors and coupled inductors. I am using a powder core for both design which have a flux saturation at approx 10000 gauss or 1 Tesla so for my single inductors it is not neccesary to use an air gap but for many designs of coupled inductors i have seen, they are using an air gap. Is this neccesary even though you are well below the saturation or is the air gap needed for correct functionality of the coupled inductor? Thank you in advance, Best Regards

Thanks

Hi. Could you please post a link on the mentioned video about inductors and transformers design. And a small question regarding this video. When you demonstrated B(t) with positive and negative flat tops, does it mean that the coil at these moments has DC-current through the coil, i.e. B=N*Idc/(S*A)?

Thanks. Most absorbing the effect of 3?? Materials and frequency. What about super conduction of core and winding??

Sir, can you please share the source of the F x Bmax Vs frequency graph (timestamp: 14:42)

6:43 This is not correct: the loss coming from hysteresis is just one part, the other one comes from the core eddy currents, which gives Pe = k*f^2*B^2 (valid for linear materials), so the total losses are k1*f*B^2 + k2*f^2*B^2. In total, for nonlinear materials, these exponentials are given by Steinmetz coefficients alpha and beta and typically beta>alpha.