A mechanically switched superconducting flux pump

A device for inducing a current flow in a load, comprising:

• a rotor which comprises at least one magnetic field generator configured to rotate with the rotor, wherein the at least one magnetic field generator generates a magnetic field, and
• a stator,
• wherein the stator is provided with one or more lengths of superconducting material arranged to provide an induction coil, and a switch, and two or more output terminals configured to connect to the load in use, the two or more output terminals being electrically connected in parallel with the switch,
• wherein in use the rotor is configured to rotate relative to the stator, and the at least one magnetic field generator is configured to periodically apply the magnetic field:
• to the induction coil to induce a current flow in the induction coil, and
• to the switch to transition the switch between a low-resistance state and a higher-resistance state for a given current flow within the switch.

A rectifier comprising:

• a rotor which comprises at least one magnetic field generator configured to rotate with the rotor, wherein the at least one magnetic field generator generates a magnetic field,
• an induction coil, and
• a switch comprising one or more lengths of superconducting material,
• wherein, in use the rectifier is configured to connect to a load, the load being connected electrically in parallel with the switch,
• wherein in use the rotor is configured to rotate to move the at least one magnetic field generator relative to the induction coil and switch, to periodically apply the magnetic field to the induction coil and switch such that:
• a current flow is induced in the induction coil, the current flow having a positive component and a negative component over time, wherein at least part of the current flow is configured to flow through the switch, and the load, and
• the magnetic field applied to the switch reduces a critical current of the superconducting material within the switch, such that the magnetic field and the current flow within the switch cause the switch to transition from a low-resistance state to a higher-resistance state,
• wherein the application of the magnetic field to the switch is synchronised with the positive or negative component of the current flow, such that the switch transitions to the higher-resistance state to increase the amount of current flowing in the load during the positive or negative component, thereby providing a net positive or negative current flow in the load.