HAULING CHECKING METHOD OF CAR-PHONE

摘要

The howling protection method of the car-phone comprises the hand free microphone (1); the first switch controlling the transmission audio path (SW3); the hand set microphone (2) connected with the front-end of the first switch; the speaker (4); the second switch (SW5) controlling the receiving signal input terminal, the CPU (5) controlling the first and second switch and sensing the ON/OFF hook condition of the handset; the first step (100) researching whether ON hook state of the phone hand set is changed into OFF hook state or not; the second step which turns off the switch and converts audio path to the receiver (3).