Steve ;

i didnot reverse it
now at the moment i can control the speed of motor with tacho feedback
the only problem the motor doesnot turn smooth
you know if i reverse it
the motor would turn opposite direction with full speed


Raghunathan ;

C=1nF R=68K max. freq = 10 Khz
as i told Steve , i didnot close the "position" loop
i only give a speed command of 1 V - and watch motor turn 200 rpm
the problem is that the motor doesnot turn smooth -
it vibrates
i cannot go all digital - my 8052 would have no time for main tasks - the tacho algorithm would take all its resources ( i think )

again my question
do u know any other tacho generator IC on the market ?