| 摘要 |
PURPOSE:To reduce the wear of a battery by opening a telephone line automatically when it is detected that a communication opposite party hooks on or noise production takes place or the electric field strength is weak so as to bring a mobile set in the standby state. CONSTITUTION:When a station does not generate a CPC signal and a communication opposite party hooks on, a busy tone or a no-sound is inputted from a telephone line. When a VOX detection circuit 5 detects the signal, an output is given to a control means 6. The means 6 uses the output to deenergize a telephone line closing relay 3 and sends a talking end signal to the mobile set. The mobile set uses the signal to turn of a transistor(TR) 22 and to be transited to the standby state. When noise is caused by a disturbing radio wave or a distance between a stationary set and the mobile set is parted or the electric field strength of a received radio wave is weak during talking resulting in causing difficulty of talking, a noise detection circuit 18 of the mobile set detects that noise takes place or the electric field is weak and gives an output to a control means 19. The means 19 uses the signal to turn off the TR 22 and to be transited to the standby state. |
