Digital radar speedometer

[MNA]

i think it not work by magic. Ok, this radar works with the doppler effect. It converts variation of frequency into frequency and it measures this frequency to display the speed. The variation of the frequency of the modulation is created by the impact of vehicle against the wave. More the speed of the vehicle is high, more the variation of the frequency will be high. At the speed of the light, the rythm of variation of frequency is the same as the modulated frequency. You can determine the output frequency if you know the modulated frequency value and speed of the car.

I think for that u must know the transmitted frequency ......Can it be known here?
how's the variation of the frequency taken and passed to display speed(in which part of the crkt, as mixer is used for rf crkts) ?.....

U said 74hc can be used here.....I again read the desciption of the crkt and it says ttl type shoulb be used.....74hc is cmos type??
Thanx

 

[yunus cesur]

The AS and HC ICs are in the same case.
The AS is much faster and operates at a much higher frequency than the HC.

 

[MNA]

Laser radar block diagram and explaination:-

http://profusion.ittc.ku.edu/publications/documents/Allen2002_RSL%20TR%2018680-2.pdf

View attachment 39111

 

[audioguru2]

That is another way to do it. Who is going to design a circuit that works that way?

 

[hazanohazizul]

The AS and HC ICs are in the same case.
The AS is much faster and operates at a much higher frequency than the HC.

74AS can be replaced by 74HC because i already asked the author of the crkt....
he say that the 74AS is a fast and high frequency ic but 74HC is higher to...
there was only a little bit different in they frequency respons..

 

[MNA]

I think for that u must know the transmitted frequency ......Can it be known here?
how's the variation of the frequency taken and passed to display speed(in which part of the crkt, as mixer is used for rf crkts) ?.....

?

That is another way to do it. Who is going to design a circuit that works that way?

I will design it ...but for that we have to wait for atleast 1-2 yrs. since this subject is not included in my course this year......I am unable to understand themethod upon which e-lab project is based....Can u tell me which method of the two looks good....And please don't get angry with me....I can't leave that work which seems to be hard or impossible....I always try to make it possible ....It's my habit.