| 摘要 |
<p>PURPOSE:To provide the vehicle movement detector which obtains a high sensitivity for the movement of a vehicle and suppresses erroneous detection due to external oscillation other than movement. CONSTITUTION:A receiver 3 detects the fading of an extremely high frequency through an antenna 1, and a reception level discriminating circuit 4 discriminates that the reception level is higher than a certain level, and a time width discriminating circuit 5 discriminates that the reception level is kept for a certain time or longer. A transducer 6 detects sounds due to the movement of the vehicle, and an amplifier 7 amplifies the signal, and an amplitude level discriminating circuit 8 discriminates the level, and a time width discriminating circuit 9 discriminates that the amplitude level is kept for a certain time or longer. An output time discriminating circuit 10 outputs a detection signal indicating the movement of the vehicle unless respective output signals of time width discriminating circuits 5 and 9 are outputted at the same time.</p> |
