Flexible heating elements with patterned heating zones for heating of contoured objects powered by dual AC and DC voltage sources without transformer

摘要

A heating element made from flexible circuit technology with a single contiguous heating zone for uniform heating or multiple temperature heating zones is described. These flexible heating elements can conform to three dimensional object surfaces with irregular shape. The heating element's overall flexibility and its thickness (in the region of 10 mils) allow for heating many object shapes in an efficient, compact and light-weight manner. Each thermal sensor or thermostat is used to regulate each heating zone and provide a unique temperature setting. A thermostat can be mounted directly on an object's metallic surface. In addition, using diodes connected to the flexible heating element is described here to allow the use of two or multiple voltage sources. The technique permits one heating element to be powered from either AC or DC sources with comparable heating characteristics from both. The technique also eliminates the use of a transformer, which makes the heating solution simple and particularly compact and lightweight.