On 12 Jan 2005 21:10:02 -0800, "ContestID67"
wrote:
1) The meter is only 0-1vdc so you have to add a two resistor bridge to
scale the input range you need. The instructions tell you how.
2) There is no scale on the meter, just red/green markings.
3) There are three wires. Ground, a +5 to +12vdc supply to power the
meter and a sense line.
The meter can also be wired to read current by using it to measure the
voltage across a fixed 1% resistor. E=IR comprende?
Yes, that works, but a 1 volt drop for full scale is a lot on a 28V
system, and even more on a 14V system (use 24 and 12 in this sentence
if it makes more sense).
NORMALLY, a meter used to measure courrent won't have but about 50mV
or 0.1V drop at full scale ... try to find something lower if you want
to read discharge currents. If this is a motorglider with electric
start, the resistance of the battery cable is often enough to develop
enough drop for this 1V meter ... for starting current. In testing
ground based circuits like this, I will often clip on the crimp on
each end of the cable. Absolute, no ... relative, yes, and
repeatable. It can be calibrated.
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