I am trying to create a simple circuit to test gate drive transformer models. My +/- 5V Input is fine but the secondary outputs go from 0 to +25V and 0 to -25V. I am expecting to see a bipolar output. (The transformer is 1:2.5:2.5). What am I missing?

 

Welcome to AAC!
With such high values of inductance and such short pulses you may have to run the sim for a lot longer to get the +- waveform you want. Try 1 sec.

 

I am trying to create a simple circuit to test gate drive transformer models. My +/- 5V Input is fine but the secondary outputs go from 0 to +25V and 0 to -25V. I am expecting to see a bipolar output. (The transformer is 1:2.5:2.5). What am I missing?
View attachment 341501


View attachment 341500

The inductance ratio should be the square of the turns ratio.
so inductance is 1/6.25

For example, If Lp is 1m then Ls is 6.25m

Your values are correct.

Your graph is correct also.
One output is 0 to+25v. The other is 0 to -25v

 

Your graph is correct also.
One output is 0 to+25v. The other is 0 to -25v

If one thing is certain then it is the graph being wrong.

 

For the short sim time you are using the graphs appear correct. Big inductances slow down current change. Your inductance values (in Henries) seem way too high for a gate driver application.

 

Here is a modified file that allows you to change the scale parameter and see how it affects the settling time of the bipolar waveforms.
HTH