| 摘要 |
PURPOSE:To enable a listener to hear an emergency alarm which is delivered as a time point out of the normal broadcasting hours at night, by providing a magnet switch incorporating a radiowave receiver. CONSTITUTION:A listener turns off the switch of a TV or radio set and goes to bed when the TV or radio broadcasting is over at midnight. If a disaster, etc. breaks out during these hours and an emergency alarm is delivered with radio waves, an emergency alarm input device works to feed radio waves of a TV or radio set. The input radio wave is amplified by a frequency converting circuit 4 via a tuning circuit 3 and undergoes the shaping of waveform at a wave detecting circuit 6 via a transformer coupler 5 to be fed to a low frequency circuit 7. The circuit 7 actuates a magnet switch 8 to given an input to a power supply line 10 of a TV or radio set. As a result, the power supply is fed to the TV or radio set which is so far off to enable the reception of broadcasting. |
