Drawing circuits with K netlist statements

[danieljfarrell]

The following circuit without mutual inductance statement draws fine (in Jupyter notebook)

c = Circuit("""
Vs 1 0 ac; down
Rs 1 2; right=1.5
R1 2 3; down
L1 3 4; down
R2 4 5; down
L2 5 6; down
W 0 6; right
W 4 7; right
Rl 7 8; down
W 6 8; right
""")

Adding K statement line prevents the draw function from finishing. It seems to get struct trying to calculate the layout.

c = Circuit("""
Vs 1 0 ac; down
Rs 1 2; right=1.5
R1 2 3; down
L1 3 4; down
R2 4 5; down
L2 5 6; down
W 0 6; right
W 4 7; right
Rl 7 8; down
W 6 8; right
K1 L1 L2 1;
""")

I'm using lcapy version 1.1.

[mph-]

Ahh, this is a bug; a weird graph is created for the schematic node positioning. This is because the K component makes the assumption that the two coils are side by side and so tries to draw them as a transformer. The easiest thing is to add the ignore keyword

K1 L1 L2 1; ignore

Do you have any ideas of how to show the mutual coupling?

[danieljfarrell]

In LTSpice the K statement just appears next to the coupled inductors as text. Which is I don't particularly like, but it is probably the most pragmatic solution because it is not dependent on the physical layout of the inductors. I suppose the only thing I can thing is a Bezier curve passing through both windings, to indicate shared magnetic flux?

[joaoantoniocardoso]

The curve to indicate shared magnetic flux seems a good idea to me, also the inductors could be changed to use the cute choke, from CircuiTikZ.

[mph-]

If you can think of a good algorithm given an arbitrary pairing of inductors with different orientations, I could implement it.