TELEPHONE SET FOR INSTALLATION ON TRAVELLING OBJECT

摘要

PURPOSE:To realize a reduction of power consumption during the queuing time, by throwing in the main power source of a hand-free telephone only when necessary for a call. CONSTITUTION:In case the close-talking microphone 9 is used, the electrostatic switch 10 is turned on. Then the power supply control circuit 14 detects the ON of the switch 10 and switches the switch circuit to the side of the microphone 9. At the same time, the power supply control relay 15 is actuated by the circuit 14. Thus the power is supplied to the main control circuit 16 and the speaker driving amplifier 22 via the relay contact 17 to secure a call with the other side after a connection of the circuit secured by a dial operation of the key matrix 18. While in case a floor- type microphone is used, the voice is amplified by the microphone amplifier 12 and transmitted to the level deciding circuit 13. The relay 15 is actuated by the circuit 14 when the level of the voice is constant for a certain time. When an incoming arrives during the queuing time, the ringing tone is detected by the ringing tone and busy tone detecting circuit 21. Then the relay 15 is actuated by the circuit 14.