Replaceable signal cable making a sound-controlled or externally dialed hand-free system universally compatible with all types of cellular phones

摘要

A replaceable signal cable for connection of a specific type of cellular phone to a sound controlled or externally dialed hand-free system enables the hand-free system to be adapted for universal use on all types of cellular phones by simple selection of a proper signal cable in use. In other words, it relates more particularly to a signal cable for a hand-free system, which can be selectively replaced with ease so as to make all types of cellular phones universally adapted to one single hand-free system. The signal cable is equipped with a first connecting plug coupled with a cellular phone and a second connecting plug connected to a hand-free system. A dial-decoding IC or circuitry housed in either the first connecting plug for a cellular phone or the second connecting plug for a hand-free system is adopted according to codes set by a standard communication protocol for each type of cellular phone. So, simple replacement of a signal cable permits a hand-free system to be universally applicable to all kinds of cellular phones.