Condition for ensuring a satisfactory stability range in a p.w.m. system using the method of Murphy and Wu

The method developed by Murphy and Wu to estimate the range of pulse amplitude M for which a pulsewidth-modulated (p.w.m.) system is asymptotically stable in the large is discussed. A necessary and sufficient condition for which the method of Murphy and Wu can yield satisfactory results is developed, and it is established that the method fails for systems containing integrating elements.