I think the general principle of the "Terry Filter" is
applicable no matter what type of transformer you use,
and I personally would use one on any HV power supply
that I was fond of and didn't want to risk destroying.
Just the component values need changing depending on
what type of power supply you're protecting. For
instance, a pole pig or MOT stack is obviously going
to burn the series resistors that Terry recommends for
a NST, and an X-ray transformer would smoke the MOV
strings unless you added more to increase the clamping
voltage.
I've seen Steve Ward use a Terry Filter to protect the
output rectifier on a home-made HF capacitor charging
supply. And I imagine it can be used for protecting
the charge inductors and de-Q-ing diode in a DC
resonant spark-gap coil too. I never bothered, but
only because the inductors and diodes in my coil cost
less than the parts for a Terry filter, and I've not
had any failures.
Steve Conner
http://www.scopeboy.com/