METHOD AND APPARATUS FOR DETERMINING WHEN A TELEPHONE HANDSET IS OFF-HOOK

摘要

Apparatus in an automatic telecommunications system which communicates between a central location and at least one remote location over the switched telephone network, senses changes in loading of the telephone line which correspond to a telephone handset going off-hook, to serve as an indication that a handset has gone off-hook and to cause the automatic telecommunications system to relinquish its use of the telephone line, or not to itself go off-hook if a telephone handset is in use.