Regarding fuse indicators, would it not be a better idea to have a
voltage-present indicator at the fuse holder itself? It's a neon bulb with
a resistor (assuming mains) or a LED with a resistor (assuming low-voltage
DC), built into the equipment itself instead of into the fuse.
The advantage is a wider choice of fuses, and no premium cost.
The disadvantage is the need to hack the equipment in question.
A potential disadvantage is the issue of power consumption, as the LEDs
take some current when the fuse is not blown. However, the modern blue and
"hypergreen" LEDs using GaN/InGaN architecture can shine with appreciable
brightness even at 0.1 milliamp (tested with a hypergreen LED, 12V
circuit, and 100 kOhm serial resistor). If such level of power consumption
is still a concern, all the cathodes of the LEDs can be connected to the
ground through a "TEST" pushbutton, to light them up on need. In case of
vehicles, the switch can be an end limit switch connected to the lid of
the fuse box.
The disadvantage of the SmartGlow fuses is that later you will inevitably
get a mix of glow and nonglow fuses in the equipment (as Murphy makes it
less likely to have a spare glow fuse than a nonglow one in case of need)
and due to natural selection the nonglow ones will be in the positions
most likely to blow.
The fuses also depend on the protecte circuit being of a relatively low
resistance, which may be a condition that is not always satisfied, e.g. in
case of switched off car headlights. An assumption that the fuse is OK
when it does not glow can therefore in such case add an appreciable amount
of time into the troubleshooting by leading the technician into a false
track.
On Fri, 11 Jan 2008, R. Snyder wrote:
>
> A good idea, but not a new idea. I have WWII-era fuse
> indicator comprising a NE-2 neon bulb and resistor in
> a phenolic tube with brass clips to engage the ends of
> a cartridge fuse. I bent over the brass clips and
> soldered extension tabs to them to accommodate the
> spacing of adjacent terminals on a 66M punchdown
> block. It makes a handy relatively high impedance
> ring indicator for locating a ringing line.
>
> --- Its from Onion <areda..._at_msn.com> wrote:
>
> > Very good idea.
> >
> > They do cost more than standard fuses, but I think
> > the potential time
> > savings in troubleshooting makes them worth the
> > expense. The current
> > product line includes both the small size, standard,
> > and large blade
> > fuses with amperage ratings of between 3 and 40
> > amps. My only
> > complaint is that they don't currently offer a 1 amp
> > fuse which would
> > be helpful for accessories. I got mine at an Auto
> > Zone store, but
> > they're available at most automotive parts stores
> >
> >
> >
> http://www.smartglow.com/cgi-bin/r.cgi/index.html<http://www.smartglow.com/cgi-bin/r.cgi/index.html>
> >
> >
> >
>
>
>
> ____________________________________________________________________________________
> Be a better friend, newshound, and
> know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
>
>
> >
Received on Sat Mar 02 2024 - 00:57:19 CST