Nix McRetro
There I was replacing a fuse in a Super Famicom when I noticed the original part was marked 1.5 A, 125 V.
My first thought was:
“125 V? But this is Australia! We have 250 V fuses here!”
That was the wrong reason.
A fuse’s voltage rating is the maximum circuit voltage at which it is designed to interrupt safely.
A 250 V rated fuse can therefore be used in a 125 V, 12 V or other lower-voltage circuit, provided the rest of its characteristics are appropriate.
It does not mean the Super Famicom somehow has Australian mains voltage running through its internal fuse.
So a compatible 1.5 A, 250 V PICO fuse can replace an appropriate 1.5 A, 125 V fuse.
The current rating should not simply be increased, and matching amperage alone is not enough. Fuse speed, interrupting capability and physical format matter too.
My capacitor comparison also needed a qualifier.
With capacitors, using the specified capacitance and an equal or higher voltage rating is often appropriate, but polarity, capacitor technology, ESR, ripple-current capability, temperature rating and physical size can also matter.
Maybe electronics does work according to rules after all.
How would I know?
I’m just the weekend staff! ;)