Pyroelectric conversion system

Abstract

When the temperature of pyroelectric film is increased from low to high near its phase transition temperature its ability to hold electrical charge on its surfaces diminishes, and the charge can be drawn as current through an external load resistor. Once the film temperature reaches a steady temperature, no more power can be drawn. However, if the film temperature is lowered again, it will restore charge on the film surfaces and the pyroelectric conversion process can be repeated. Because pyroelectric conversion depends on the degree of temperature change and the repetition rate of the process, the faster the cycling the more power it can generate by converting heat to electric power. An improved apparatus and method is disclosed for converting heat to electrical energy with a multi-layer stack of thin pyroelectric films. The pyroelectric film surface is cycled between higher and lower temperatures by the displacement of higher and lower temperature fluid over the film surface. The system alternates hot and cold fluid without reversing direction of the fluids over the films to achieve rapid thermal cycling with this uni-directional fluid flow. A novel voltage controller slave to a magnetic proximity switch mounted on a rotating flow controller, provides synchonization of the thermal and electric cycling of the pyroelectric films.