RE: E-meter amps help (how did it live?)

[Paul G <neong@gte.net>]

Roger wrote:
>Perhaps what you did was to disconnect one of the shunt sense leads,
>allowing it to float about 50mV from the other sense lead and
>resulting in the E-Meter reading nearly full scale (509 out of a
>possible 511)?

The shunt leads go directly to the shunt, 2 stops, shunt and e-meter. They
where both connected still. Other wires in the box go to a terminal strip
(except the charging wires, they are also direct and 10ga). It was the 14ga
constant pack negitive that I disconnected, killiing the negative pack
connection for both the Todd and the prescaler. And the Todd discharges
pretty quick with the door open (dome light).

>From the description of your setup, it sounds that if you had
>disconnected the ground lead, then everything up front (including the
>E-Meter DC/DC) would have lost power, and so it couldn't have
>displayed anything.  If the E-Meter DC/DC runs off the accessory
>battery and you disconnected the pack ground, then the E-meter could
>have floated relative to the pack, but as long as both shunt leads
>were still connected to the shunt, it should have read ~0A.

The e-meter runs off the accesory battery, through a DC>DC. That negative
connects to the same point as the prescaled pack negative, at the e-meter.
So the e-meter was powered and displaying still. I agree with the logic of
the statement above, but it didn't match what I actually saw. And so I
started wondering (while thanking my wife for catching it, and thanking the
e-meter for surviving).

Neon