| 摘要 |
PURPOSE: An entry/exit control system using an amplified ultrasonic sensor is provided to reduce human life loss and property damage by adopting a stable detection force of the ultrasonic sensor installed with an amplifier. CONSTITUTION: An ultrasonic sensor(21) has an ultrasonic wave transmitter controlled electrically and an ultrasonic wave receiver to sense the received ultrasonic wave electrically. And an amplifier(22) is attached to the transmitter and the receiver of the ultrasonic sensor, and is extended to the front from the transmitter and the receiver according to a distance and sensitivity of an object to be sensed. Thus, the entry/exit control system can detects a vehicle or a person sensitively without an error. |
