Approximate and exact air gap effect in ferrite core inductors

[@tangy1181]

The BEST power electronics lectures as ALWAYS! I just love the matching between theoretical analysis and real world values! Thank you!

[@sambenyaakov]

Glad you like them! Thanks

[@ymym4977]

Now I have the best channel to pick up more EE knowledges, thanks!

[@sambenyaakov]

🙏😃

[@SMV1972]

Огромное спасибо. Прекрасное изложение материала!!

[@sambenyaakov]

Спасибо תודה

[@vicentematricardi3596]

Thank you very much Yaakov , I am watching your classes little by little , they seem excellent to me , I feel that you have a true knowledge , you are worthy of admiration , a warm hug !!!!

[@sambenyaakov]

Thanks

[@theoldbigmoose]

Highly informative presentation Professor. Thank you!

[@sambenyaakov]

Thanks

[@sambenyaakov]

🙏🙂

[@hamidk4772]

Outstanding Job.

[@ToBeDefined85]

Thank you for your informative videos Mr. Ben-Yaakov. Please keep on doing them.

[@sambenyaakov]

👍🙏

[@StanZurek]

Interesting mention of Encyclopedia Magnetica.

[@sambenyaakov]

Thank you Prof. Zurek for your immense contribution to magnetics knowledge and the marvelous e-magnetica🙏🙏🙏

[@chaolinshi1816]

thanks

[@sambenyaakov]

🙏🙂

[@gouravag]

Hi sir, Can you add a video on current sensing techniques in dc dc converter? I have started learning dc-dc converters but I have not found any good materials on current sensing techniques. And Thank you for your awesome videos.

[@sambenyaakov]

In the search window of KZbin write" sam ben yaakov current sensing"

[@gouravag]

@@sambenyaakov Sir, Thank you so much for your reply. Perhaps, I didn’t clarify my question earlier, sorry for that. I want to learn about low/high side current sensing techniques in current mode control converters.

[@sambenyaakov]

@@gouravag have you seen kzbin.info/www/bejne/p3_IgIqAr5eii9k ?

[@tamaseduard5145]

👍🙏❤

[@sambenyaakov]

🙏😊👍

[@dor7sh]

Hello Prof. is there a way to utilize the fringing effect to our advantage in a design?

[@sambenyaakov]

Good question. I am not aware. Hold on. Magnetic heads of the old tape recorders apply the friging flux to magnetize the tape😃

[@Stelios.Posantzis]

4:48 "it makes the inductor smaller": the inductor size is here determined exclusively by le and Ae, of which, le seems arbitrarily defined and is only set as equal to lf + lg where each of which terms in turn is arbitrarily defined since the definition of one implies the definition of the other and vice versa. In other words, how do you define lg when lf is zero? Can an equation for the inductance be given, containing both lg and lf where lf is allowed to go to zero? I'm not clear on this.

[@sambenyaakov]

Thanks for discussion, good point. The definition of mue, assumes a homogeneous ferromagnetic body with no gap in which B is confined to the body. One this assumption is violated one can not use this model. With no lf device becomes a selonoid. Interstingly, the equation for the inductance is the same when l is the length of the solonoid.

[@Stelios.Posantzis]

@@sambenyaakov Yes, exactly, this is what I was finding strange - unless the formula for the air core solenoid has a 1/2 factor (I cannot remember if it does) in which case that would mean that the formula for le/mu_e was still right.

[@sambenyaakov]

@@Stelios.Posantzis No, it does not have a division by 2. And my intuitive explanation is that outside the solenoid the flux is spread out so if you take a loop Hdl the H in the outside is very small 😊

[@Stelios.Posantzis]

@@sambenyaakov So then, we are stuck with a formula for inductance that is not general (for any inhomogeneous magnetic path). That's weird: one would think that someone ought to have come up with a general formula for this by now...

[@sambenyaakov]

@@Stelios.Posantzis I would surmise that it is possible to come up with a general formula. But it is the practice of workers in the field to make life easier as in other cases. Take for example a BJT or MOSFET, you can use the complete set of non linear differential equations or, for gain derivations, you can use an equivalent linear model at the operating point. I will choose the latter.

[@MrDp9000]

Dear Prof. Can you please make a video on analytical calculations of leakage inductances ( specifically for multiwinding transformer).

[@sambenyaakov]

Good suggestion. Will Try.