On 09/15/04 04:35 ET, Ernie Bornn-Gilman said...
One thing to look for is that the trigger will
likely not put out enough current to actually
close a relay. If this happens, the relay will
not close and if you measure the voltage on the
relay, it could be as low as a half volt...which
will then spring back up to twelve when you disconnect
the relay.
I solved this once by amplifying the current,
and that took an irritating amount of time.
The second time, I took the trigger voltage, ran
an LED with it, bought a Niles light sensor, put
the LED next to the light sensor, wrapped the
whole thing with black tape, and I got 12 volts
out when the projector was on, 0 volts when the
projector was off.
I, too, have had trouble with low output 12v triggers. B&K and Lexicon both have used them. After fooling around for years with Radio Shack reed relays and other stuff I've found that Niles offers an optocoupler, the OPT-512 (I think) that does the trick. Also, Elk offers a relay that trips at 1.2ma of output for some $25 or so.
