i need the working principle of digital radar speedometer
its link here http://english.cxem.net/izmer/measured25.php

 

That very circuit has appeared numerous times. I am not aware of anyone who has actually reported that it works. Ask yourself, why does the distance need to be "exactly" 90 m?

John

 

Hmmmm, if it uses a laser wouldn't that be a LIDAR?

The basic circuit is pretty suspect.

 

From what I see, there is no synchronization or time comparison between the laser driver ( a free running oscillator) and the clock driving the counters (another free running oscillator). I agree that the drawing, although interesting, would not do what it is supposed to do.

 

That very circuit has appeared numerous times. I am not aware of anyone who has actually reported that it works. Ask yourself, why does the distance need to be "exactly" 90 m?

John

I think the "exactly 90m" is so it comes close to km/h, since there isn't enough logic to do a calculation.

Overall, I'd rate the circuit as a "curiosity" rather than something functional or useful. e.g. Techy gag gift for fun or similar.