Analysis of the phase space of discontinuous systems via classical methods of the theory of oscillations can be quite a difficult task. Moreover, in some cases this analysis is impossible to perform. Due to the emergence of frequency methods for analysis of discontinuous systems and the development of various analytical-numerical methods, it has become possible to give a more accurate description of the phase space of systems with discontinuous right-hand sides. The present report tries to adopt to the Watt's governor model that takes account of the self-regulation of the object and the derivative action. We compare the results with those obtained by rigorous analytical method.