Wireless sensors supplied by energy harvesting thermoelectric generators

The use of energy harvesting for supplying wireless sensors becomes a new market opportunity. During lasts years, new low power transmitters, and also power conversion ICs specifically designed for energy harvesting, have become commercially available. However, as any other power supply circuit, the specific load behavior affects to the power converter, doing that just joining the two parts takes to a non-functional device. In this paper we will measure experimentally the transmitter current of some technologies, for the several sensor states. With this information, some required modifications in the power stage will be proposed. A complete temperature sensor design and assembly is showed. The sensor has been tested in a tandem cold mill, and several experimental results are included.