D-earthlink-A9

Doug Says: Doug replies: I am interested in enlisting your assistance in designing a handheld device that will accelerate a drive wheel capable of driving by means of friction a steel disk approximately 18 inches in diameter to a user input speed temporally stored in memory from 50 FPM to 2000 FPM and for the Europeans in meters with the user input of direction of rotation and display of speed and then can be accelerated faster in small recurring increments of fpm. currently I rotate an 19 inch circumference wheel by means of a variable speed drill motor with its axle in the drill motor chuck and with my other hand hold a handheld tachometer to read the speed when the unit activates. I would prefer it to be somewhat accurate in speed + or - 1 fpm, affordable to construct I was considering PID or PWM, not decided on how to receive speed, Quadrature via encoder or optical encoder or coupling and counting the spikes from the commutator bars. What do you think? Thank you in advance, Doug Schoen tooned@earthlink.net+

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