Primary telephone line protector with failsafe

Printed wiring board cable cover

Procedure and device for adaptive digital cancellation of the ec

Process and device for adaptive digital cancellation of the echo

Process and device for adaptive identification and adaptive echo

Process and system for improving echo cancellation within a tran

Process for determining an echo path flat delay and echo cancele

Programmable constant current “off hook” circuit

Programmable device and methods for disabling a ring signal...

Programmable peak detector for use with zero-overhead Class...

Programmable subscriber line circuit partitioned into high...

Programmable subscriber line circuit partitioned into high...

Programmable subscriber line circuit partitioned into high...

Programmable subscriber loop interface circuit and method

Protected telephone network interface device

Protected telephone network interface device

Protected telephone network termination module

Protection arrangement for a telephone subscriber line interface

Protection circuit for telephone systems

Protection circuit for use with a telephone appliance and method