shaft speed measurement with my prop

science_geek

i have been playing with tesla turbines lately, and i kind of just estimate the rpm of it because i dont have a tachometer that can measure the speed of it because its to fast, my school doesnt have a tach either. i was wondering if this http://www.sparkfun.com/commerce/product_info.php?products_id=247·along with a long hole in the center of the output shaft, would work, my main question is, is the propellor fast enough to recieve an on off input if the shaft would spin between 20,000 and 60,000 rpm, which is very fast

Capt. Quirk

So long as your only measuring 1 input/360' @60,000 rpm or 1,000 revs per second, that's only 1 revolution per .001 second.

Piece of cake. Read the app note 001.