Electronic Amp Meter

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 >> Stay informed about: Electronic Amp Meter 

"Ross Herbert" <rherber1SPAMEX.RemoveThis@bigpond.net.au> wrote in message
news:0c1e715cl60tghtk9787gdovsccv8vso3r@4ax.com...
>
> Replying to Rheilly's post with this question is not the done thing.
> Your question should have been directed to the OP.

yeah sorry my mistake.
 >> Stay informed about: Electronic Amp Meter 

Just about any auto parts store carry those

David

Tony Christian wrote:

> Can some point me in direction for a wiring diagram to build an Electronic
> Amp Meter to read up to 50 amps charge/discharge? This for automotive use on
> a 12V DC system.
>
> Or does some know where one can buy one off the shelf?
>
> Regards
>
> Tony Christian
 >> Stay informed about: Electronic Amp Meter 

Try:

www.cruzpro.com/a30.html

Remote sensing and programmable to use a 5.0 to 900 amp shunt

Regards,

Bert van den Berg
CruzPro Ltd.
www.cruzpro.com
35 Keeling Road, #A4
Henderson 1008
New Zealand
Tel: 64-9-838-3331
Fax: 64-9-838-3332



"Tony Christian" <afh1.RemoveThis@westnet.com.au> wrote in message
news:4275d6ee@quokka.wn.com.au...
> Can some point me in direction for a wiring diagram to build an Electronic
> Amp Meter to read up to 50 amps charge/discharge? This for automotive use
on
> a 12V DC system.
>
> Or does some know where one can buy one off the shelf?
>
> Regards
>
>
> Tony Christian
>
>
 >> Stay informed about: Electronic Amp Meter 

Hi,

You could buy the BMV-501 several companies offer this device. I have a
Victron. www.victronenergy.com

Lasse
"Tony Christian" <afh1 DeleteThis @westnet.com.au> wrote in message
news:4275d6ee@quokka.wn.com.au...
> Can some point me in direction for a wiring diagram to build an Electronic
> Amp Meter to read up to 50 amps charge/discharge? This for automotive use
on
> a 12V DC system.
>
> Or does some know where one can buy one off the shelf?
>
> Regards
>
>
> Tony Christian
>
>
 >> Stay informed about: Electronic Amp Meter 

On Mon, 2 May 2005 11:01:49 -0400, "Glenn Ashmore" <gashmore.RemoveThis@cox.net>
wrote:

>That type is probably the most practical digital ammeter for that kind of
>use but one caution. The power to run the meter has to be isolated from the
>circuit being measured. They need either a battery or an isolated dc/dc
>converter to power them.

===========================

Is that because the meter needs a floating ground, or is there another
reason?
 >> Stay informed about: Electronic Amp Meter 

> Date: Mon,May 2 2005 8:01
> From: "Glenn Ashmore"
>
> The power to run the meter has to be isolated from the circuit being measured.
> They need either a battery or an isolated dc/dc converter to power them.

After some search it looks like the typical 200mV digital meter modules
take about 1 to 2 mA.
Even if I use a couple of them, for voltage and some currents (to
trolling motor, other loads), I need max. about 10 mA. For this low
current, a transformer to isolate the DC seems to be overkill.

I am considering to take a simple 555 and insert a capacitor not only
in the output signal line, but also the return (no common 0V anymore)
line. On the "secondary" side would be a simple bridge rectifier, a 9V
Zener diode, and a capacitor to smooth the ripples.

Did anybody try something like that already? Other simple solutions?

TIA,

Stefan
 >> Stay informed about: Electronic Amp Meter 

Larry,
those DC/DC charge pumps obviously produce an output voltage that is
higher than the input voltage, or negative. But the output still has a
common ground (0V) with the input voltage. For the panel meters we need
a supply voltage that is within the range of the available voltage (12
to 24V available, 9V needed) (no need for those DC/DC charge pumps),
but that needs to be isolated/free flowing from the main/"primary"
power supply so that we can measure it, i.e. no common 0V/GND. I don't
see how the ICs that you show can do that. On the other side, I wonder
whether there are not really specialized ICs that do that.

Thanks,
Stefan
 >> Stay informed about: Electronic Amp Meter 

There are special chips for the purpose, inverting dc/dc isolators. They
are expensive; $10 a piece as I recall.

I had a lot of trouble with this whole setup; you need a separate isolator
for each panelmeter [volts, amps] I had a meter for each of several
alternators.

a loose connection on a heavy user [DC air compressor powered by a starter
motor] caused a spike that blew 2 isolators and panel meters. I added more
protection, reverse diodes and clamps; a few months later, again some
distant fault blew a couple of my panelmeters, even though I had bought more
expensive ones this time that were supposed to be internally protected as
well..

I'm not sure that the idea is at all practical in reality, these meters seem
just too delicate for our world.

I'd love to hear from people who have successfully installed a bunch of
panel meters on a boat or similar system. I have a couple set up to read
temperature as well, one for the engine room in general and one for the
house batteries [you need to adjust the charging voltage for battery
temperature].

regards, Mark Holden



"stefanhanoi" <stefan.probst.DeleteThis@opticom.v-nam.net> wrote in message
news:1117358631.177262.217350@g49g2000cwa.googlegroups.com...
> > Date: Mon,May 2 2005 8:01
> > From: "Glenn Ashmore"
> >
> > The power to run the meter has to be isolated from the circuit being
measured.
> > They need either a battery or an isolated dc/dc converter to power them.
>
> After some search it looks like the typical 200mV digital meter modules
> take about 1 to 2 mA.
> Even if I use a couple of them, for voltage and some currents (to
> trolling motor, other loads), I need max. about 10 mA. For this low
> current, a transformer to isolate the DC seems to be overkill.
>
> I am considering to take a simple 555 and insert a capacitor not only
> in the output signal line, but also the return (no common 0V anymore)
> line. On the "secondary" side would be a simple bridge rectifier, a 9V
> Zener diode, and a capacitor to smooth the ripples.
>
> Did anybody try something like that already? Other simple solutions?
>
> TIA,
>
> Stefan
>
 >> Stay informed about: Electronic Amp Meter