In this work, the new configuration of magnetorheological clutch (MRC) is proposed to control the output speed of electrical motor. This configuration deals with some drawbacks in conventional configuration such as bottle-necks phenomenon, using collector with brushes (commutator). The Bingham model has been employed to analyse the transmitting torque of MRC. An optimal design of the MRC is then established to find out the optimal geometric dimensions of the clutch that can transform a required torque with the minimum mass and power consumption. Based on the results, a prototype of the MRC with 10 Nm transmitting torque has been manufactured, and its performance characteristics have been experimentally investigated. In addition, a controller has also been designed to control the output speed of the system. In order to evaluate the effectiveness of the proposed motor speed control system, experimental results of the system are obtained and presented with discussions.