Timeline for How to measure flux in transformer in LTspice?
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
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| Nov 22, 2023 at 21:05 | comment | added | Andy aka | @tobalt I have no idea what you are talking about because it's the magnetization current that gives flux so considering a more complex equation that what is necessary is just over-complicating things without a sensible reason. | |
| Nov 22, 2023 at 20:47 | comment | added | tobalt | I found that it doesn't matter which of the windings I use in expression 2. They all yield the same result. So summing over all 4 windings just replicates quadruple the values. I guess it makes sense. One should use a winding in approach 2, it doesn't matter whether it is a driven one or not. With Rohat's explanation, I could also make the first expression agree with expression 2. (A scaling by turns ratio is missing in expression 1) | |
| Nov 22, 2023 at 20:12 | comment | added | tobalt | Yes the sign of currents has a fixed relation to the dots. I will check if I can make the two equations agree based on your discussion of the issues with the second approach. | |
| Nov 22, 2023 at 20:10 | comment | added | Andy aka | @tobalt that sounds reasonable providing the signs are connect (easy to get in a muddle over signs) but, by the looks of it you have got your dots in the right place and, assuming that LTspice determines current direction using dots then it should be OK. I don't use LTS so I can't be sure. | |
| Nov 22, 2023 at 20:04 | comment | added | tobalt | I follow your reasoning. And based on it, I conclude that the second expression is wrong because it includes also Vs integrals from "undriven" windings. However, the first expression should cancel loading effects because primary and secondary load-related currents are opposite in sign, so only the magnetization current should be left in expression 1, no? | |
| Nov 22, 2023 at 19:19 | history | answered | Andy aka | CC BY-SA 4.0 |