The Parametric Transformer: A Power Conversion Device Demonstrating the Principles of Parametric Excitation

The paper introduces the parametric transformer as a device which provides a simple demonstration of the theory underlying parametric excitation and resonance. Following a review of the historical development of parametric devices, the operating principles of the parametric transformer are explained on the basis of the stability chart of the Mathieu-Hill type differential equation. The graphical techniques presented in the paper facilitate a ready understanding of the basic phenomena associated with the operation of parametric devices, and these techniques are extended to cover the description of various inherent characteristics of the parametric transformer which are useful in power-conditioning applications.