Circuit to indicate the simultaneous off-hook condition of at least two of a plurality of telephone subsets on the same telephone line

摘要

A visual indicator is contained in each of a plurality of telephone subsets on the same telephone line. A logic circuit is connected between the hookswitch of each of the plurality of telephone subsets and each of the visual indicators to activate the visual indicators when at least two of the plurality of subsets are detected to be in an off-hook condition simultaneously.