| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the situation generating radio wave interference at transmission time without giving a bad influence to a transponder function, even in case of transmitting charging power through an antenna coil relating to a built-in secondary battery of a remote key provided with the transponder function. SOLUTION: An ignition key 1 has a transmitter function transmitting a remote signal for a door lock mechanism by an output of a built-in secondary battery and a transponder function replying a prestored discrimination code by utilizing a carrier wave signal when the carrier wave signal and a question signal are received from a transceiving ECU 16, the secondary battery is charged by utilizing the carrier wave signal. In the transmitting/receiving ECU 16, in the case of transmitting the carrier wave signal and the question signal through an antenna coil 15, transmission power of the signal is relatively increased, but thereafter in the case of continuously transmitting the carrier wave signal for the secondary battery, transmission power of the signal is controlled so as to be in a relatively low level through a power amplifier 26.</p> |
