Hello Carl,
Thanks for sharing an example with .model NIGBT. We have seen only a very few so far.
The ¡ì character will be added, if a device defined with .model has not the correct character in the first place of its reference designator. A NIGBT needs a Z for the first character, Z10 and Z11 instead of Q10 and Q11.
Your circuit design needs two decoupling capacitors (to GND) in? a real circuit. After I added these to capacitors, the simulation will run without any "tricks". See my .TRAN.
I wonder why you set your PULSE source with 10 pulses. I removed this number 10. Most people add here a number, because they think it's needed for the correct syntax. Standard SPICE doesn't have this parameter at all. That's whjy I highly recommend to ommit this number from PULSE().
Have you checked the primary ripple curernt of your output transformer?
It's a decade too high, because the primary inductance with only a few micro-Henry is far too low.
I have uploaded a new circuit with these changes - "_funny character in error log.asc".
Best regards,
Helmut
