| 摘要 |
<p>PURPOSE:To prevent incorrect operation of controlled device completely by applying transmission reception alternately through an electromagnetic wave between a 1st transmitter-receiver and a 2nd transmitter-receiver so as to control the device to be controlled remotely. CONSTITUTION:With a switch of a 1st transmitter-receiver 20 turned on, a trigger signal is converted into an electromagnetic wave by a 1st transmission circuit 25 and the wave is transmitted. A code signal generating means 42 of a 2nd transmitter-receiver 40 generates a 2nd code signal when the received signal is a normal trigger signal and the code signal is converted into an electromagnetic wave by a return circuit 45 and the result is transmitted. The 1st transmitter-receiver 20 judges whether or not the received signal is the normal 2nd code signal and in the case of the normal signal, a code signal generating means 22 generates the 1st code signal, which is converted into an electromagnetic wave and it is transmitted. The 2nd transmitter-receiver 40 judges whether or not the received signal is the normal 1st code signal and in the case of the normal signal, an operating signal is given to the device to be controlled. Thus, illegal operation of the controlled device is prevented.</p> |
