The development, design and construction of a variable speed drive using a synchronous motor is described in this paper. At first, the operation of motor with a current-fed, motor e. m. f. commutated inverter is explained. The working of control circuitry is explained next with the aid of logic and functional blocks. The power circuit, comprising the converter, inverter and motor has been reduced to simple blocks so that the controller design by hand computations becomes possible. It has also been shown that the digital simulation based on simplified block diagram is accurate enough for obtaining the responses of the system to step changes in speed reference and load on motor. © Taylor & Francis Group, LLC.