High temperature superconducting opening pulser switch with compact thermoelectric source

Abstract

A high temperature superconducting switch with external magnetic field switching was utilized to switch a thermoelectric source. The superconducting switch was constructed of filaments of yttrium-barium-copper oxide (YBCO) ceramic and switched with an externally applied magnetic field. The superconducting switch is being used as an opening switch for a thermoelectric current source. The thermoelectric source, based on Seebeck is capable of high current, low voltage generation. It consists of a series of hot and cold junctions, arranged in series to increase the voltage of the system. Source output is a function of temperature differential between cold and hot junctions. The superconducting switch operates at liquid nitrogen temperature. Therefore, liquid cryogen is available to the cold junctions of the current source, and, with sufficient heat applied to the hot junctions, a significant temperature differential, far greater than that obtained using conventional cooling, is available, thus increasing the overall efficiency of the system. The device sees application wherever a fast acting, lossless switch or current limiter is required, with a compact, simple power source, neither of which have any moving parts to fail or wear.