SPEED CONTROL USING POTENTIOMETER
all resistors 1/4 W
Potentiometer 4.7 k or 5 kOhms 1/2 W or bigger (due to shaft Isolation issues), I used RV24YN20S 5K Potentiometer, you might have to alter the values of R1 and/or R2 depending on tolerances.
Enjoy!!
kreutz