HIGH-TEMPERATURE SUPERCONDUCTING SWITCHES AND RECTIFIERS

There is provided a rectifier of an alternating input current, which may comprise: an electrical switch comprising a length of HITS material to carry an alternating switch current, the HITS material having a critical current: a magnetic field generator to apply a magnetic field to the HTS material: a control mechanism to control the magnetic field generator to switch the switch between a low-resistance state when a magnitude of the magnetic field is relatively low and a higher-resistance state when a magnitude of the magnetic field is relatively high, the relatively high magnitude being sufficient to reduce the critical current so that, for a part of the alternating switch current cycle, the current approaches the critical current, is substantially equal to the critical current or is greater than the critical current. There is further provided an electrical switch having two strands of superconducting material arranged in a bifilar arrangement.