| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the generation of noise on a receiver, when the power on a transmitter side is turned off, without especially necessitating a tone circuit or a tone detection circuit. SOLUTION: When the power of the transmitter 10 is turned off, a control means 14 of the transmitter side gives the mute control pulse signal lying outside of the audible frequency band, to a radio frequency transmission means 13, and the mute control pulse signal is transmitted as radio wave and a pulse control signal is detected by a controller 22 in the receiver 20 side and causes a mute circuit 23 to be operated.</p> |
