I was checking the eqivalency of the inductor model and the transformer model as shown in the Qspice- Device Refereence Guide.
page 368. In page 116 you can see the inductor model.
For load: R_load=30: works fine,yet the transfer functions are completely different for other loads when N1!=N2.
I also have noticed there is no apparent change/influence when you modify R_par for the transformer x1 model.
The coupled inductance and transformer model have different Transfer functions when N1!=N2. They match under big load response, but differ for low Load. Can someone give clarity on what is happening here?
Here is a 10:1 ratio, with a 0.1 ohm loading. The output of my schematic still matches… it’s weird. Any idea what the difference might be between your setup and mine?
Primary inductance should be identical in comparison. And you don’t have to feed leakage into formula when K1 L2 L3 1. I think you took the K coupling factor section formula and misuse in here.
primary of coupled inductor L2 is L11
secondary of coupled inductor L3 is L22 = L11 / ( (N1/N2)*(N1/N2) )
Thanks for the quick response. I am not sure, maybe is the using of parameters instead of numbers. I’d attach here my qsch, but I am a new user and does not allow it.
I see other difference is that you are using K^2 as a division in the secondary, I use it as multiplication in primary. (As shown in page 116).
R1 and R2 are not equal in the above schematic. I tried a 10:1 ratio with R1=R2=0.001, and they still appear to be the same. Are you observing an equivalent condition that produces a different response?
Sorry, that post was wrong and I edit it (was my mistake, because I changed only one load resistance) Thats the main reason I am using parameters in my schematic, I only have to change the value in one place and assure I am using the same values.
I think has to do with the values: If I use the same values as your simulation it matches quite good, yet they are not exact:
Yes…when I remove Kc^2 and set the L22 = L11 / ( (N1/N2)*(N1/N2) ) function it works! The trafo model uses the number of turns model and not the Coupling.
I am not sure, maybe is the using of parameters instead of numbers. I’d attach here my qsch, but I am a new user and does not allow it.
