The Daring Dufas wrote:
On 9/21/2013 8:17 PM, Tegger wrote:
"(PeteCresswell)" wrote in
:

Specially LittleFuse KLK-15 as in http://tinyurl.com/kfs8gje

This thing is almost certainly blown (ohmmeter shows same reading with
or without fuse in circuit)... I'm looking at and looking at it, but
can't see any visible indicator.

There is none, right?



Correct: No visible indicator. Fuses with transparent bodies or windows do
allow visual detection of failure, but even that isn't a dead-certainty,

Do not test the /circuit/, test the /fuse/.

To determine whether or not the fuse is blown, you MUST remove it from the
circuit (or at least one leg of it), and check between the fuse terminals
with a multimeter set to ohms, A good fuse will show zero ohms. A bad fuse
will show considerably higher than zero.


It's actually very easy to test a fuse in circuit. There are three
different settings on a DMM that will allow you to do it. Explain it and
you get a gold star. It's actually the best way to test BFF, Big
Fracking Fuses and those that bolt in. ^_^

TDD

This is not an answer to your quiz, but we used to test BFR (Big Fracking
Resistors) by banging them on the edge of the workbench.

These were foot long, 1" diameter ceramic resistors used in LORAN-C
transmitters. Before we'd meter them, we'd bang them on the edge of the
workbench. These resistors had a habit of getting brittle before they
failed. We preferred that they cracked while out of the transmitter rather
than when they were in a 15K VDC circuit.

The arc across a cracked resistor makes a lot of noise.