"N_Cook" wrote in message
...
When did they first arrive and do they always have an unusual body colour?
There is a patent reference to 1977 but when would the first appearance in
domestic equipment have been ?.
Resistors that fail open circuit if a designed-in current capacity weak
point is exceeded , fuse-fashion, not just the thermal limit of the body ,
so often no overheating discolouration to the body or surrounding board


Fusistors have been used in test equipment for many years in the input
section. Fluke uses them in all the meters.
I know, I've replaced many in the past.

Shaun