> As I recall, Philips published pulse duration versus power tolerance
> curves for their resistors (or some of them). Based on experience,
> Philips resistors are rather superior in reliability to unknown
> source oriental units in real life equipment. (Philips resistors are
> probably known source oriental units :-)).
> .
> I can't recall exactly where I saw this - probably in one of the
> Philips monthly technical documents that they issue - It may be worth
> asking your Philips technical rep about this.
> .
> .regards
>
>         Russell McMahon.
> .
> -----Original Message-----
> From: Morgan Olsson <    >
> ....
> Do anybody have experience of how good carbon mass resistors are for
> fusing?
> (Wold be very type dependant though)

I worked with carbon composition and carbon film resistors about
10 years ago for use in lightning surge suppressors where the
fusing characteristics have to be "fuse" like, i.e. leaving a true open
circuit when overloaded to destruction.
Metal films were no good as they tended to sputter onto the pcb
and the inside of the enclosure depositing the vaporised metal
which defeated the purpose of the excercise.
My experience with carbon film resistors was that they were not
reliable in their failure mode (some left a carbon track across the
surface after failure) but that carbon composition were excellent for
the job.
I haven't looked lately so don't know if this type of resistor is still
manufactured.

Regards

David Crookes