本实用装置可以测出汽车前、后障碍物的距离,汽车行驶速度,通过数码显示和声音提醒,让驾驶员注意,并可自动刹车,防止碰撞事故.这一装置由超声发射电路1、超声接收电路2、计数电路3和4、显示电路5和6、磁接收电路7、速度译码制动电路8、复合电路9、驱动电路10及电源11构成.如电路框图所示. The utility device can detect the distance between the front and the rear obstacle of the automobile and the traveling speed of the car through the digital display and the sound reminding, so that the driver can notice and can automatically brake to prevent the collision accident. The device consists of an ultrasonic transmitter circuit 1, The receiving circuit 2, the counting circuits 3 and 4, the display circuits 5 and 6, the magnetic receiving circuit 7, the speed decoding and braking circuit 8, the composite circuit 9, the driving circuit 10 and the power supply 11. As shown in the circuit block diagram.