| 摘要 |
<P>PROBLEM TO BE SOLVED: To inexpensively and securely detect failures without superimposing a pilot signal and to reduce a noise component superimposed on an ATC signal. <P>SOLUTION: An ATC in-vehicle device includes an amplification part for amplifying power of the input ATC signal, and a failure detection part with a mechanism for shutting an output of the ATC signal by detecting failures of the amplification part. In the ATC in-vehicle device, a level adjusting unit is arranged for variably adjusting power of the ATC signal in the preceding or following stage of the amplification part. On the basis of an ATC signal input voltage which is input to the amplification part, an ATC signal output voltage which is output from the level adjusting unit, and a gain setting value of a level adjusting unit, the failure detection part calculates a ratio between the ATC signal input voltage and the ATC signal output voltage, and compares the ratio with a total gain calculated from the gain of the amplification part and the setting value of the level adjusting unit. Thereby, output of the ATC signal is shut off by securely detecting failures of the amplification part or the level adjusting unit without superimposing the pilot signal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
