| 摘要 |
PURPOSE: A method of automatically controlling a ring volume level of a key phone is to automatically minimize the ring volume level of the certain key phone which is not used among a plurality of key phones, thereby preventing power dissipation. CONSTITUTION: A timer counts a predetermined time. Whether a key input operation and an off-hook operation are input to a key phone is determined. If the key input operation and the off-hook operation are not input to the key phone, the time counts the predetermined time. If the counting operation of the timer is completely finished, The ring volume level of the key phone is set to a minimum value, and then the counting operation of the timer is re-performed. If the key input operation and the off-hook operation are input to the key phone, the counting operation of the timer is stopped. The ring volume level of the key phone is set to a desired level predetermined by a user. The above all operations are controlled by a central processing unit according to a preset program. |
