Hi,

There's one thing I don't understand about the schematic and that just looks
plain wrong. If both W2 and W3 jumpers are present, the 5.6k resistor is
shorted out, thereby connecting the -2.5V and V- rails together. Surely this
can't be right, or am I missing something?

If operated from external supplies, all three links should be removed as
opposed to battery operation where they must all be in place. You are right in
that the 5.6k resistor is shorted-out but it is not needed in that
configuration. Two links (W2 & W3) are required then to 'remove' the resistor
and re-make the connection between the -ve power sensing detector and the
bottom of the battery.

I didn't know the piece of equipment but looked it up out of curiosity.


Cheers - Joe