N
N_Cook
- Jan 1, 1970
- 0
W for Wood's metal for the fusible part ?
Googling "wood's metal" AND "fusible resistor" produces nothing
Googling "wood's metal" AND "fusible resistor" produces nothing
N_Cook said:W for Wood's metal for the fusible part ?
Googling "wood's metal" AND "fusible resistor" produces nothing
N_Cook said:W for Wood's metal for the fusible part ?
Googling "wood's metal" AND "fusible resistor" produces nothing
Michael A. Terrell said:'T' was already used for 'Transformer'.
Why "U" for an IC ?
'I' was already used for 'Indicator'.
Michael A. Terrell said:It shouldn't. You don't want molten metal loose inside equipment.
Older fusible resistors were nichrome wire in a fiberglass, asbestos or
sand housing. A few manufacturers used carbon resistors, but running
them right at the rated current caused them to age, and the resistance
to rise, which caused false trips. The original Motorola 'Quasar, Works
in a drawer' TV chassis did this on the audio output transformer. You
had to use the specified brand and wattage resistor for repairs, because
of variations between brands. Metal film has replaced nichrome wire in
modern equipment. You wand the failed fuse to vaporize the conductor,
not melt it and let it still make contact, or worse, create plasma which
will carry a lot higher current than the fuse did.
Eeyore said:Yes, modern 'fusible resistors' are typically made using metal film over a
ceramic former and covered with a 'cement' coating. All of which is
non-combustible and flameproof..
In comparison, carbon film covered with laquer is very combustible.
Graham
Ross Herbert said::W for Wood's metal for the fusible part ?
:Googling "wood's metal" AND "fusible resistor" produces nothing
Can't say I have ever heard of Wood's Metal being used for fusible
resistors in
electrical or electronic equipment. I seem to remember that a major use
for
Wood's Metal was as the fusible element in thermal break-circuit fire
detectors
used back in the 30's - 50's. They were superseded by much better
detectors.
Eeyore said:Wimpy resistor ?
Graham
Arfa Daily said:There certainly used to be a pellet of Wood's in the 'daisy' fire
sprinklers. I don't know of that is still the case. It's a simple, reliable,
and more to the point 'on-the-spot' and unpowered system. The lid of my
pressure cooker still has a Wood's metal pressure pressure relief valve,
which coincidentally, I replaced just last week.
Arfa
How about "CR" for a diode ? Copper (oxide) Rectifier, maybe ?