T: picture 1, top
Telephone Line Indicator
Only indicates V
AB
(1) <> 0 V. Also indicates the ring signal.
T: picture 1, bottom left
V
AB
(0) : DC 48 - 50 volts, a free phone line
V
AB
(1) : DC 7 - 10 volts or 0 volts, a busy phone line
Menu
