Rustydust
Active member
Lots of the newer cars have a back-up sensor that warns the driver before the rear bumper actually comes into contact with something. Surprisingly it was not developed by modern automotive engineers using the latest technology. It was disclosed recently that the first to develop the back-up-sensor was a Chinese Farmer.
His invention was simple and effective. It emits a high-pitch squeal when the vehicle backs into something.
This is a picture his first prototype:
https://lh5.googleusercontent.com/-esGe0...4645187530.jpeg
