On Fri, 27 Jun 2008 05:03:22 +1000, Herodotus
wrote:

On Thu, 26 Jun 2008 07:44:39 -0700 (PDT), Terry K
wrote:



It'll be OK. I won a bet 30 years ago amongst my peers, 20
electronics techs, did a demonstration, all that.

What tiny problem arises is with the timing. Two 10 Amp fuses in
parallel pop a little sooner than one 20 Amp.

Terry K

Hi Terry,

Will the "little sooner" be much of a problem practically?

Peter

I would have said that the fuses would blow at somewhat less than the
sum of the rated currents - that is, two 10 amp fuses in parallel may
blow at 18 amps rather than the expected 20.

This is because the resistances in the two paths are unlikely to be
identical, so path will carry a little more than half the current,
causing that fuse to blow when the total current is less than the
total rating. (Of course, a fuse will not blow instantly at exactly
its rated current, even for fast-blow types, and the fuse rating
should always be somewhat more than the expected maximum current, so
this discussion may be somewhat academic...)

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
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