[Test-Equipment] Ideas ?

[J. Forster]

George Shaw wrote:

> switching at the moment via the negative wetting voltage supplying spare
> contacts that mirror the actions of the ones being monitored.

Your meaning is unclear here.

Suggestions:

1.  Use opto-isolators. Put an opto-isolator LED and series R across each
relay's coil. The photo transistor can be biased with a pull-up R and the output
goes to the logger.

2.  If the coils are AC, you could pot a small torrid (possibly split) on a coil
lead and detect the AC voltage with another winding. A signal diode bridge and
small C would make it into DC if you want that for the logger.

3.  A variant of (2) would be to put a turn or two of wire over the existing
relay coil.

-John