interfacing of 8051 with dc motors

[ganto17]

how do i interface a dc motor (24V,between 1-2 amperes) using a 8051 microcontroller..which would include sped control and dorection control also.it would be very helpful if the interface can be done using a ULN or a mosfet as an interface...which is more reliable?...and on which site can i get the circuit design of such an application.

[8733mags]

To control a DC motor you need to control the polarity of the supply to give you direction of rotation, you need to control the current to control the torque output of the motor and you need to control the voltage applied to the motor to control speed. To maintain stable control of the motor, you should fit a tachogenerator to the rear of the motor and use the output of the tacho to feedback into the "motor controller" It is possible to use armature voltage feedback to help regulate the speed of the motor but speed accuracy will be poor +/- 10%. I doubt if you will be able to meet the needs of the motor with a simple mosfet. I would suggest you look at a proper electronic drive either thyristor controlled or better still a small PWM servo drive such as a Mini-Maestro which has all the features you need to make a stable motor.