Analysis of nonlinear RC op-amp oscillators utilizing phase space techniques

This thesis presents the results of a study of applying phase space and describing function analysis to a class of nonlinear oscillators. The oscillators are nonlinear because they use thyristor elements in the feedback path of the operational amplifier. The op-amp is the active device used in the oscillator model. Phase space analysis is applied directly to second and third-order RC models in conjunction with computer solution of the state equations and computer plots of the output state variable. A fourth-order phase shift model is also considered. A design criterion is developed based upon the peak value of the output state variable and the input resistor to the op-amp. Describing function analysis demonstrates that the linearized differential equation closely follows a linear version of the nonlinear oscillator considered.