Re: 3 blown Power supply's in 6 months.

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In article <42815F9B.9CA0D817@xxxxxxxxxxx>, w_tom1@xxxxxxxxxxx says...
> Fuses in that radio would be required by the UL so that it
> does not kill someone. If fuses are routinely blowing, then
> fuses are too small - nuisance tripping. That too
> demonstrated in another post with numbers.

There you go assuming you know why they blew, and that they blew many
enough times to mean they were too small for the reason they were
installed. Fuses that have blown 3 times in 20 years is not significant
in some circuits, but I don't expect you to have any experience in that
area either.

> To protect electronics, a fuse must blow in microseconds.
> But again, you damn the numbers. You know better because
> undersized fuses in a Radio are nuisance tripping. That alone
> is sufficient proof of what? Next you will claim a UPS
> provides protection that even its manufacturer does not
> claim. Why? Your speculation, as ususal, is proof enough.
> Numbers be damned.

You've got to be kidding - many devices can take minutes of excessive
load without being damaged, some hours, you really have never worked
with electrical devices of a varied nature - have you?

> For others, numbers are provided elsewhere. Fuse takes
> numerous seconds or minutes to protect from an overload. But
> after damage has occurred, the higher current will quickly
> open the fuse - to protect human life.

Again, you miss the mark - fuses do take time to open, some open in
milliseconds, some open in seconds, some longer, but since you've not
posted any specific fuse and the load you are suggesting, we can't
really suggest if the fuse blows quickly or slowly.

If I draw 1.05A on a 1A fuse it may never blow, or it may blow after
minutes, but if I draw 1.7A on it, it's going to blow quickly - even
though all of the devices in the rest of the circuit could handle the
load for several minutes without damage - the idea is that the fuse
blows as quickly as needed to protect the circuit and it's parts.

Ever hook a multimeter to a 600V line on the wrong setting? The little
315MA fuse blows in less than a millisecond (I would have to guess), but
there is no damage to the device, and the foil on the circuit board
would vaporize before damage to human, so there was no reason to have it
there to protect the human, it was there to protect the foil traces on
the circuit board or other components inside the multimeter.

None of these REAL examples have anything to do with protecting a HUMAN,
it's about protecting the device.

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