Use a bi-color LED as an ammeter?

"Paul Hovnanian P.E." <Paul@Hovnanian.com> wrote in message
news:41DA1558.177413BE@Hovnanian.com...
Rheilly Phoull wrote:

[snip]

What you really need is an ammeter that under no current flow
indicates '12
oclock' and for discharge the needle swings to the left, should the
conditions produce a charge to the battery the needle swings to the
right. I
reckon this could really catch on if someone chooses to make such
devices.
Even the colour blind could interpret that.

Its been done. I have one on my truck and I can't figure out why auto
mfgs stopped incorporating them into dashboards.
Click to expand...
Because they started way too many fires with full charging current
flowing thru them.

I an see why someone might want to save some real restate on a
motorcycle instrument cluster by going with an LED.
Click to expand...
 
Anthony Fremont wrote:
"Paul Hovnanian P.E." <Paul@Hovnanian.com> wrote in message
news:41DA1558.177413BE@Hovnanian.com...
Rheilly Phoull wrote:

[snip]

What you really need is an ammeter that under no current flow
indicates '12
oclock' and for discharge the needle swings to the left, should the
conditions produce a charge to the battery the needle swings to the
right. I
reckon this could really catch on if someone chooses to make such
devices.
Even the colour blind could interpret that.

Its been done. I have one on my truck and I can't figure out why auto
mfgs stopped incorporating them into dashboards.

Because they started way too many fires with full charging current
flowing thru them.
Click to expand...
Crappy design. Mine is a milliammeter across a shunt in the battery
line, with 1/4 amp fuses in the meter circuit and a fusible link off the
battery.

--
Paul Hovnanian mailto:paul@Hovnanian.com
------------------------------------------------------------------
What color is a chameleon looking in a mirror?
 
"Paul Hovnanian P.E." <Paul@Hovnanian.com> wrote in message
news:41E2043C.54997D1@Hovnanian.com...
Anthony Fremont wrote:

"Paul Hovnanian P.E." <Paul@Hovnanian.com> wrote in message

Its been done. I have one on my truck and I can't figure out why
auto
mfgs stopped incorporating them into dashboards.

Because they started way too many fires with full charging current
flowing thru them.

Crappy design. Mine is a milliammeter across a shunt in the battery
line, with 1/4 amp fuses in the meter circuit and a fusible link off
the
battery.
Click to expand...
Well...that would be the safe way to do it, but manufacturers sure did
it the "crappy" way for a good many years. :-/ I wonder why.
 
"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.01.10.05.19.10.708275@example.net...
On Sun, 09 Jan 2005 21:59:31 +0000, Anthony Fremont wrote:
"Paul Hovnanian P.E." <Paul@Hovnanian.com> wrote in message
Rheilly Phoull wrote:
What you really need is an ammeter that under no current flow
indicates '12
oclock' and for discharge the needle swings to the left, should the
conditions produce a charge to the battery the needle swings to the
right. I
reckon this could really catch on if someone chooses to make such
devices.
Even the colour blind could interpret that.

Its been done. I have one on my truck and I can't figure out why auto
mfgs stopped incorporating them into dashboards.

Because they started way too many fires with full charging current
flowing thru them.

Come on. You can't be serious. The full charging current doesn't go
through the dashboard meter. It's a zero-center voltmeter, and all it's
reading is the voltage across a shunt, surely not over a few volts, at
milliamps, if that.

Cheers!
Rich
Click to expand...
Not sure about the newer cars, but I know for a fact that many of the
older cars ( '60s etc) used ammeter with the full current going through
it. You should see the melted wires on my '76 suburban ... as near
as I can tell, when they were putting in the steel brake line for the
trailer brakes they tried to push it through the main plug in the firewall
and shorted wires out -- many melted wires and bypassed wires.
I have had to replace a number of them to get things back fully functional
again (no, it wasn't me - I know better !!)

mikey
 
Rich Grise wrote:
On Sun, 09 Jan 2005 21:59:31 +0000, Anthony Fremont wrote:
"Paul Hovnanian P.E." <Paul@Hovnanian.com> wrote in message
Rheilly Phoull wrote:
What you really need is an ammeter that under no current flow
indicates '12
oclock' and for discharge the needle swings to the left, should the
conditions produce a charge to the battery the needle swings to the
right. I
reckon this could really catch on if someone chooses to make such
devices.
Even the colour blind could interpret that.

Its been done. I have one on my truck and I can't figure out why auto
mfgs stopped incorporating them into dashboards.

Because they started way too many fires with full charging current
flowing thru them.

Come on. You can't be serious. The full charging current doesn't go
through the dashboard meter. It's a zero-center voltmeter, and all it's
reading is the voltage across a shunt, surely not over a few volts, at
milliamps, if that.
Click to expand...
Even if they do it this way (my Landcruiser does), think about where the
main battery lead goes next. To a fuse block under the dashboard. The
exposure to damage isn't going to be increased much more by passing it
through a high current ammeter located in the same vicinity.

The important safety feature in any of these designs is a fusible link
just off the battery.

--
Paul Hovnanian mailto:paul@Hovnanian.com
------------------------------------------------------------------
This isn't right. This isn't even wrong. -- Wolfgang Pauli
 
"Paul Hovnanian P.E." <Paul@Hovnanian.com> wrote in message
news:41E2F6CE.61BFE006@Hovnanian.com...
Rich Grise wrote:

Come on. You can't be serious. The full charging current doesn't go
through the dashboard meter. It's a zero-center voltmeter, and all
it's
reading is the voltage across a shunt, surely not over a few volts,
at
milliamps, if that.

Even if they do it this way (my Landcruiser does), think about where
the
main battery lead goes next. To a fuse block under the dashboard. The
exposure to damage isn't going to be increased much more by passing it
through a high current ammeter located in the same vicinity.
Click to expand...
But in a vehicle that doesn't do this, the main battery lead goes to the
rear of the fuse block, outside the passenger compartment. Out there
where you can't even get your hands on it, all covered in tape and
rubbery sealant goop so it can't wiggle, flop, or fray. ;-) I still
believe that the full-current-thru-the-meter style is just asking for
trouble.

The important safety feature in any of these designs is a fusible link
just off the battery.
Click to expand...
Of course, as long as it hasn't already done its job and been removed
from the system for being a nuisance. ;-) I only wish I had pictures
of all the "clever" wiring I've seen in cars.
 
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