I have to develop an electronic starter for 230 V, 2HP DC motor as my B.Tech project. After rectification of initial power, I am using MOSFET to control the armature voltage through PWM technique. The whole problem is to control armature current by applying gradually increasing voltage at the time of starting. I don't know which technique would be best for this purpose. For MOSFET control, Some advice to use 555 ramp generator along with comparator, some say to use op-amps only and some say to go for digital timers. Is PWM best technique for this or some better technique is there ?? Will these controllers be able to drive MOSFET connected in 207 V DC power circuit???? Please help me with the power and controller circuit design ..