In this study, electromechanical equations of separately excited DC motors are examined and the exact electrical equivalent circuit related to mechanical equations is introduced. The motor has mechanical variables and components in both armature circuit and output circuit related to load. The electrical equivalent circuit having the same equation structure with mechanical system is given. By using the similarity of equations, all of mechanical variables and components are expressed in terms of electrical circuit elements and electrical variables. Thus, all variables and components in the model are electrical although the DC motor system contains mechanical components and variables. The transient-state and steady-state analysis of DC motor with load and without load are obtained by using the exact electrical equivalent circuit in the numerical example. (C) 2012 Elsevier Ltd. All rights reserved.