i am a student studing electronic eng an i have to creat an rpm meter. Since this is inly a procejt my reacher sugessted to use a function generator insead of a motor. my aim is to make an RPS for now! in the second the counter will count the number of oscillations done and will display to the 7 segment. My problem arises from here, how can i make the 7 segment displaying for o.5 seconds after counting, then reset the counters? Any help please. here i attached my schematic and i am convinced that if i remove the small glitch in the MR i would accomplish my task.

 

An RPM meter is basically a scaling variation on a frequency counter, therefore you can get useful help by examining circuits for same. Main difference is the range, whereas a frequency counter is scaled in repetitions per second the RPM meter is repetitions per minute. So you need the gating time to the counter scaled in minutes or fractions thereof. You could take a frequency counter reading and multiply it by 60 to get RPM.

 

10x for your help sir. The problem is that my circuit is not working, because of the pulse in the MR trace at time = 3seconds. any ideas how i can remove that? thx for your help

 

hello again. i managed to solve my problem by using a flip flop so happy!!!!