[SOLVED] Speed of a moving table.

[USMCinfinity]

Hey guys, do any of you know any method or device that I can use to measure the speed of a moving table (circle)?

This is a very important aspect of calibration for a ADS calibration.

Regards,
Miguel A. Cruz

 

[emailkprajesh]

use a magnet and hall sensor. fix the magnet to the table and hall sensor to your measuring circuit.

 

[USMCinfinity]

That's the problem, I have no idea what a measuring circuit for this be like?

---------- Post added at 16:38 ---------- Previous post was at 15:47 ----------

Would there be a way to convert the output current to speed?

 

[djsfantasi]

Rather than measure the output current, count the number of times the sensor is activated in a given period of time. Since one revolution is equal to a fixed distance (circumference!), you have distance and time, thus velocity or speed. A µP could handle all of this...

 

[USMCinfinity]

Ok, so lets say the table has a diameter of 1 ft, and the sensor activated 20 times in 1 minute, hence 20 RPM. What would the speed of it be? Also what is a uP?

 

[USMCinfinity]

mph = (rpm * cir) / (gear * final * 88)

where rpm = engine rpm
cir = tire cicumference, in feet
gear = gear ratio of your car
final = final drive ratio of your car
88 = combines several conversion factors


I found this online, can I apply this formula for my situation? Eliminating the division part?