| 摘要 |
PURPOSE:To report it to the receiving side that a person who carries a device with him falls into the sea, by setting the device to the transmission state automatically for submergence of the device. CONSTITUTION:A transmitting device is constituted into such form that a person who works in a ship or the like, which is not shown in a figure, can carry the transmitting device with him. When he falls into the sea by some cause, a submergence detecting part 10 detects this state to turn on a switch part 11. Consequently, the power from a power supply part 9 is supplied to the transmitting device, and AM modulation of about 50kHz and 1kHz is performed in low- frequency signal generating circuits 2 and 3. The carrier wave from a high- frequency signal generating circuit 1 is FM-modulated by this AM modulation signal and is transmitted through amplifiers 6 and 7 and an antenna 8. Meanwhile, in the receiving side, transmitted radio waves are received and demodulated in a receiver, which is not shown in figure, to detect immediately that he falls into the sea. |
