I have no strong opinions sir, but if it's a replaceable fuse I do like
the automotive blades because every gas station has them.
On 3/21/2016 2:42 PM, Chuck McCown wrote:
I am considering adding a fuse to a new version of my rack mount POE
surge suppressors.
I know many of you like PTC resettable solid state fuses. I don’t
recall ever designing one in to anything.
Maybe I did on a phone device years ago, but that would have been to
satisfy a regulatory agency only.
Studying up on them I learn that if you have a 1 amp “hold current”
the “always trip” current is 2 amps.
Not like a fuse, which is pretty well guaranteed to trip at any
current over the rating if you wait long enough.
For a polyfuse, if your load is one amp, you have to have a design
value of greater than 1 amp hold current.
But then it takes double that to actually trip..
And then there is leakage current required to keep it in the tripped
condition.
It does not totally break the circuit.
They are fairly inexpensive compared to glass fuses and fuse holders.
Could do auto blade fuses too.
Not sure I have the room for anything but a polyfuse though.
Anyone have strong opinions about this?
