The phase dots on the "Transformer\_Centr\_Tapped\_US" & "Mutual\_Inductor2\_US" from "Spice Lib"/"System" do not indicate correct phase\.  The dots are supposed to indicate coincident rising potentials but simulations show otherwise\. Here's how LTspice (correctly) handles it (notice V(out1) is in-phase with V(in)):  Here's how "Transformer\_Centre\_Tapped\_US" behaves \(my public project Transformers\_0003\):  Here's the schematic for the above waves:  Here are the waves for "Mutual\_Inductor2\_US" \(my public project Transformers\_0004\) followed by its schematic:   Notice that in the last two cases V(out1) is out-of-phase with V(in).