Compensating the leakage inductance in the basic DC-DC transformer

This presentation is a follow up of:
Some observations on power supplies for high side gate drivers
• Some observations on p...
#DCDC_converter #Power_supply #Gate_driver #Resonant #Leakage

[@msenthilk76]

I am not power electronics guy, but I watched many of your videos and they were all wonderful!!. It helped me in my job.. thanks a lot

[@sambenyaakov]

Glad to hear that. Thanks for comment.

[@josemariamolinagarcia5562]

Well done Sam!

[@sambenyaakov]

Thanks

[@power-max]

something I forgot to mention on the last video before I watch this one, I was thinking a transformer could be designed with the use of a foil shield separating the primary and secondary. If wound on a standard E I core, the primary might be the first layer, then some insulating tape, then copper foil that doesn't make a shorted turn but connects to one of the wires, then the secondary. The field should pass through it transparently but the capacitance will have an alternate path to ground via the shield.

[@sambenyaakov]

I think this will increase the leakage inductance

[@two_number_nines]

I have seen the foil trick done in some commercial transformers

[@JacquesMartini]

The path for the capacitive current will be different (over the shield) but the capacitance and therefore current will be high. This will cause EMC problems.

[@esijal]

Thanks Professor,👌

[@sambenyaakov]

🙏😊

[@gaozihan4]

This looks like a reverse version of LLC🤣, which may explain some of the behavior too.

[@sambenyaakov]

Or series resonant converter. In any event a resonant converter.

[@benm4784]

Great video professor! Does the smaller capacitor cause the output voltage to sag more with larger load current?

[@sambenyaakov]

Not really

[@popovlist]

Many thanks professor. Can I use this concept to directly drive the gate, instead of using it just as a supply. So it is like isolated driver?the overall frequency will dictate the switching speed, I guess

[@sambenyaakov]

This would be a resonant gate drive. There are many papers on this.

[@popovlist]

@@sambenyaakov oh I see, didn't know it is called that. Will check it out. Many thanks

[@stevenbliss989]

excellent, THANK YOU!!!!! :)

[@sambenyaakov]

👍Thanks

[@tamaseduard5145]

👍🙏❤

[@sambenyaakov]

😊🙏

[@krysieks]

off topic riddle: how to measure (to model in ltspice) toroidal conductivity probe used to measure conductivity in the liquid. This is 2x toroidal inductors submerged in liquid so they form circuit of two transformers where winding is a liquid. Google for "transformer conductivity measurement" to find some pictures of the probe construction.

[@sambenyaakov]

What do mean by "model"? That calculate the lump conductivity of the liquid surrounding the probe and the mutual coupling?? or just assuming a resistance around the two coils opening that represent the to the liquid and some mutual inductance? If the latter, how is it different from a simple transformer? Ang BTW I would think it will be MORE accurate and obviously simpler to use one toroid.

[@krysieks]

@@sambenyaakov weird I've posted replied last night and it is gone...

[@sambenyaakov]

@@krysieks ? post again

[@krysieks]

​@@sambenyaakov thank for replying me. 1. By model I mean circuit with leakage inductance, magnetising inductance, ideal transformer etc. I know how to measure parameters of simple transformer (shorting or opening second side) but having two transformers in chain is a bit confusing. 2. I am not sure I correctly understand your remaining questions. But i have done pdf which explain the problem in more details. I will paste as another comment cause i think it was the cause my comment was removed. 3. Also interesting is the concept of one coil. But how is that going to work? drive winding, receive winding, and liquid around doing as 3rd winding which will be shorted by resistance of liquid? 4. I have also found the paper: Reference: SNA 111761 which might have some answers but I'm still reading it

[@krysieks]

and here is a link to my pdf: drive.google.com/file/d/1Ik2y4VIdlNyzCC9OYblHX4294BdM5jNA/view?usp=drive_link

[@phuochoangvan5847]

Your solution is quite valuable to me. I want to replicate your result but waveforms of Vplus, ID, IL1, IL2 do not match yours. Could you send me your LT spice sim files. I would really appreciate it. Thank a lot

[@sambenyaakov]

I will try to locate it, Thanks for interest.

[@rcinfla9017]

Think you are just pushing the problem to the impedance of input driving source and creating more possibility of ringing due to MOSFET drivers peak current load spikes. Both are not in the simulation circuit.

[@sambenyaakov]

Not really. Think again. Have you done simulation?