"Grant"

They aren't designed for use at mains voltages/currents, though... at
least, I haven't seen any that are.

Me neither, other thing with polyfuses is that there's approx 2:1 current
difference between trigger point and hold point.

** That is utterly misleading !!

There are no separate trigger and hold points with PolySwitches.

The makers specs allow for some device to device variation in the actual
current level that will trigger a RANGE of similar devices to change state
and go high resistance.

The max current that fails to trip all examples of a given type is called: "
I Hold ".

The minimum current that will trip all examples of a given type is called: "
I Trip".

" I Trip " is double " I Hold".

For any given device, the trip current is one number.

Once a device has tripped, the current needed to HOLD it in the new state is
a function of the applied voltage and is generally 5 to 20 times less than
the trip current.



..... Phil