Author Topic: How to model transformer in KiCad 9.0 for SPICE simulation  (Read 1420 times)

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Offline jj5Topic starter

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How to model transformer in KiCad 9.0 for SPICE simulation
« on: September 03, 2025, 11:04:22 am »
Hi there. I have a project lab like the one shown below and I want to model the transformer it uses in KiCad 9.0 for SPICE simulation. Can someone please tell me which symbol and settings should I use for that? I'm not sure what the specs of this "transformer" are. It seems to only have a primary winding with a center tap and no secondary, is that right? I used my LCR meter to test the inductance and I got these results:

Left (18) to Center (19) = 960 mH
Center (19) to Right (20) = 960 mH
Left (18) to Right (20) = 3.6 H

Hi, I'm Jay Jay. I'm a computer programmer from the Blue Mountains, NSW, Australia. I have a beginner-friendly electronics video blog on YouTube: In The Lab With Jay Jay and I blog at blog.jj5.net.
 

Offline ahsrabrifat

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Re: How to model transformer in KiCad 9.0 for SPICE simulation
« Reply #1 on: September 03, 2025, 03:01:53 pm »
Place two standard Inductor symbols (place them so you can clearly name them L1 and L2).

Connect them like this:
Left node — L1 — Center node — L2 — Right node.
 
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Offline jj5Topic starter

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Re: How to model transformer in KiCad 9.0 for SPICE simulation
« Reply #2 on: September 03, 2025, 03:12:19 pm »
Thank you! I also added a line for mutual inductance:

K1 L1 L2 0.98
Hi, I'm Jay Jay. I'm a computer programmer from the Blue Mountains, NSW, Australia. I have a beginner-friendly electronics video blog on YouTube: In The Lab With Jay Jay and I blog at blog.jj5.net.
 

Offline radiolistener

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Re: How to model transformer in KiCad 9.0 for SPICE simulation
« Reply #3 on: September 04, 2025, 05:17:26 am »
I used my LCR meter to test the inductance and I got these results

Yes, you also neet to add coupling between inductors.

But LC measurements depends on frequency, so it's better to load s2p file taken with VNA for better simulation
 
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