multimeter advice needed

[James Weiler]

This is interesting. Can you describe where the sensor is located (how is 
it installed)?  How does this sensor work i.e. what is the principle 
behind it?
thanks again Wen,
jw



On Thu, 18 Feb 1999, Wen Yen Chan wrote:

> Hello,
> 
> Why not pull a ELD (electronic load detector) from a 86-89 Acura Integra
> or any Acura Vigor.  The sensor is used to measure the DC electrical load
> and allow the computer to adjust the idle speed and alternator output as
> required. I think the output is normalized to a 5volt scale. If anyone is
> interested I'll probe the sensor's output.
> 
> Wen
> 
> On Wed, 17 Feb 1999, Raymond C Drouillard wrote:
> 
> > 
> > On Wed, 17 Feb 1999 13:58:39 -0800 Don Holtz <daholtz at axionet.com>
> > writes:
> > >Here is an idea:
> > >
> > >Try using a current sensing resistor.  They are usuaully 1mhom (1E-3
> > ohm),
> > >and a regular voltmeter.  Put the resistor in series with the load, and
> > >measure the voltage across it.  For a 1m ohm resistor, 100A would read
> > as
> > >100A*.001 ohm=.1V  for 1A => 1A*.001ohm = 1mV.   These values are
> > readable
> > >by any resonable DMM, and the current sense resistors should be
> > available
> > >at any industrial electronic supply shop (ie.  Electrosonic in Canada).
> > >
> > >Note:  I^2R=(100A)^2*(.001ohm)10W, so use at least a 10W resistor!
> > 
> > A few years ago, I read a construction article for a high-current
> > ammeter.  It was a couple of jumper cable type clamps with a short piece
> > of copper wire of a known resistance between them.  Small sockets were
> > provided for voltmeter probes (see above).
> > 
> > >
> > >
> > >I seem to remember that inductive current meters only work on AC, not 
> > >DC!
> > 
> > I have never seen a DC current meter that reads magnetically.  It could
> > be done with a hall effect sensor, though.  It would be an interesting
> > construction project.  If you calibrate it to read in the 100A range, you
> > could read in the 10A range by wrapping the wire through the loop ten
> > times.
> > 
> > >
> > >Cheers,
> > >Don Holtz
> > 
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>