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Bruce Esquibel[_2_]

wrote:
On Sunday, May 8, 2016 at 9:28:10 PM UTC-4, wrote:
why are stereo equipment fuses glass tubes in cylindrical holders, auto
fuses in vinyl holders fuses set in plastic cases with 2 connecting
prongs out the bottom. ?????

Because automobiles have a lot more fuses, and the color coded plastic
fuses allow for a smaller denser fuse box as well as quickly identifying
rating by color.

It wasn't always like that though, at one time the glass fuses in cars were
standard. They weren't in cylindrical holders, they laid flat in a fuse
block.

But you are correct about the count/density being a factor. I had a 1964
Buick which only had 8 or 9 fuses total. There just wasn't much in the
electrical system to protect.

On the other extreme, like the 1997 Lincoln Mark VIII, there is something
like 35 fuses for all the accessories. It's only about a 4"x4" square on the
side of the dashboard, easy to get to, easy to examine.

35 glass fuses would take up a big chunk of real estate under the dash and
would probably be a nightmare to access.

If you are asking why they don't use the colored plastic ones in the stereo
hardware, I think the answer has to do with the difference of how a fuse
behaves with 12v or 120v/240v passing through them.

The glass fuses usually vaporize when they blow, reducing the chance of an
arc or flash to reseal the link. The 12v fuses just have a weak, short
element that blows between two points.

I guess there is some possibility of the fuse "re-sealing" itself under
certain circumstances (none of which I can think of).

-bruce