"Joseph Fenn" wrote ...
I often am on the internet when my wife picks up the telephone upstairs
thus breaking my connection to the ISP. Does anyone have a circuit
or know of a source for and "offline" indicators what will flash an
LED
or something so the wife will know I am useing the internet
downstairs??
Joe/KH6JF

Most of the circuits out there require a separate battery
to power the indicator because drawing enough current
from the telco loop to light the off-hook LED interferes
with the on/off hook detection.

Perhaps even better are those passive devices which
lockout other phones once the first one is picked up.
Like these (others, etc.)
http://www.glbproducts.com/catalog/s..._4737042 .htm

I believe this can be done with a single diode (some kind
of breakdown device), but I can't remember which kind or
find the circuit just at the moment.