Power MOSFETs offer many advantages over conventional bipolar transistors. These advantages include very fast switching 9 absence of second breakdown, wide safe operating area, ext-remely high gain, and high input impedance with low drive requirements. This paper presents an experemental DC to DC chopper circuit using parallel connected power MOSFETs for speed control of a seperately excited DC motor. The circuit operates from a 48 V battery and provides a maximum motoring curre-nt of 20 A. The piloting of the chopper is achieved by mic-roprocessor.