Abstract
The aim of this paper is to construct a system which can control the speed of d.c series motor by using power MOSFET chopper .The system contains close loop control which has a performance and characteristics in the operation.The close loop control system contains digital pulse width modulation circuit, driving circuit, over speed, and over current protection circuit. The power MOSFET devices are now available in production quantities and are already being utilized from switched power applications including motor control.HEXFET power MOSFET type IRFK4H350 is selected for this application due to its relative high current -handling ability up to 50A and a maximum drain -to- source voltage of 400v. All the theoretical transient responses of speed and current reveal fairly close agreement with practical response, the maximum deviation between them is (5%) .
