Hi!
I landed in here searching on a newava transformer and found
Art's SPDIF thread.
See, what had happened was I had a circuit to couple a digital pulse from an embedded controller to drive an ignition system. The success started when I cannibalized a transformer from the fax modem circuit in a Brother MFC printer/scanner. There's a
write up and circuit diagram here on StackExchange. Any other kind of driving of the ignition module would result in a noise spike that would reset the MCU.
When I disconnected my test rig and soldered everything in a proper testing rig, that transformer opened on the primary.

So I'm going to pick up a newava (and a couple other transformers) from Digi.
If anyone happens to glance at my circuit and have suggestions based upon their experience, please let me know where I'm going wrong.
Thanks for Art's thread,
Chris