| 摘要 |
PROBLEM TO BE SOLVED: To provide a power feed system of a digital multi-functional telephone set capable of using an AC adapter of an inexpensive type. SOLUTION: The digital multi-functional telephone set 14 is provided with a voltage detector 28 for detecting the output voltage of the AC adapter 16 and a supply power source selection part 22 switched based on the information of the voltage detector 28. The supply power source selection part 22 connects the AC adapter to the power source part of the telephone set so as to perform local power feed when the voltage detector 28 detects the output voltage of the AC adapter and performs phantom power feed from a main unit at the time of not detecting the output voltage of the AC adapter. |
