speed controller design for closed loop speed control for dc motor

i have to design a speed controller for closed loop speed control of dc motor ...can any body guide me

Need a teensy bit more info. Like voltage, current, response time, motor size, motor speed, etc.

speed controller

Motor:
Kw/hp .75/1
Arm/amp 4a
Rpm 1500
Arm o/p voltage 220
f/volt 220
ins class B
F/A 0.3
DC SHUNT MOTOR

to controll the speed you need to vary the current to the field for more efficient control. use dirrect rectified voltage from an A/C souce to the stator. use an AC auto trnasformer with toroid wound with a servo motor to vary the speed as per the feed back, rectify this out put and drive the field.
it involved bit of electronic to read the current speed, speed setting and to drive the servo motor to adjust the field voltage(current).

you have to come up with correct specification of the divices you are going to use to complete the closed loop controll.