Portable telephone set having a power controller causing a current charging of a battery to be held constant

摘要

A portable telephone set has a power supply in which a secondary cell is employed. A charging detector for detecting whether a charger for charging the secondary cell is connected to the power supply, wherein the charging detector generates a detection signal when it detects that the charger is connected to the power supply. A power controller turns on power of the portable telephone set when it receives the detection signal from the charging detector.