A method to operate an apparatus for feeding liquid metal to an evaporator device in a vacuum chamber, wherein the feed tube runs from a container adapted to contain a liquid metal to the evaporator device and wherein an electromagnetic pump is provided in the feed tube and a valve in the feed tube between the electromagnetic pump and the evaporator device. An at least partially gas permeable electromagnetic pump, which is enclosed in a pressure controlled enclosure, is used in the method wherein electromagnetic pump and the pressure controlled enclosure are controlled such that filling and draining of the evaporator device and feed tube can be done without affecting the vacuum pressure in the vacuum chamber.

Examples are disclosed herein that relate to a heat removal system utilizing a dispersion that includes particles of an electrical conductor. One example provides a heat removal system including a conduit loop, a dispersion of particles of an electrical conductor in a heat transfer fluid, a pair of electrodes configured to introduce a flow of electric current through the particles in the dispersion, and one or more magnets configured to introduce a magnetic field within the conduit loop in a region of the pair of electrodes, such that the electrodes are operable to apply an electromagnetic pumping force on the particles in the dispersion.

Examples are disclosed herein that relate to a heat removal system utilizing a dispersion that includes particles of an electrical conductor. One example provides a heat removal system including a conduit loop, a dispersion of particles of an electrical conductor in a heat transfer fluid, a pair of electrodes configured to introduce a flow of electric current through the particles in the dispersion, and one or more magnets configured to introduce a magnetic field within the conduit loop in a region of the pair of electrodes, such that the electrodes are operable to apply an electromagnetic pumping force on the particles in the dispersion.

A method of operating a drive circuit for parallel electric motors is provided. The method includes receiving measurements of stator phase currents in the parallel electric motors. The method includes selecting a target PM motor, from among the parallel electric motors, that generates a largest torque output. The method includes executing a vector control algorithm to generate a complex command voltage vector for the target PM motor. The method includes generating and transmitting a pulse width modulation (PWM) signal based on the complex command voltage vector for controlling an inverter. The method includes operating the inverter according to the PWM signal to supply three-phase alternating current (AC) power to the parallel electric motors.

A method of operating a drive circuit for parallel electric motors is provided. The method includes receiving measurements of stator phase currents in the parallel electric motors. The method includes selecting a target PM motor, from among the parallel electric motors, that generates a largest torque output. The method includes executing a vector control algorithm to generate a complex command voltage vector for the target PM motor. The method includes generating and transmitting a pulse width modulation (PWM) signal based on the complex command voltage vector for controlling an inverter. The method includes operating the inverter according to the PWM signal to supply three-phase alternating current (AC) power to the parallel electric motors.

A soldering pump for pumping an electrically conductive fluidin particular, a liquid soldersaid soldering pump having a feed channel which travels at least in segments along a circular path and has an inlet and an outlet, and having a device for generating a moving magnetic field, wherein the device comprises at least one permanent magnet, wherein the device is designed such that the permanent magnet is moved along the feed channel during operation.

A soldering pump for pumping an electrically conductive fluidin particular, a liquid soldersaid soldering pump having a feed channel which travels at least in segments along a circular path and has an inlet and an outlet, and having a device for generating a moving magnetic field, wherein the device comprises at least one permanent magnet, wherein the device is designed such that the permanent magnet is moved along the feed channel during operation.

An arrangement for providing a liquid metal jet in a vacuum environment is provided. The arrangement comprises a vacuum chamber; a nozzle arranged to provide the liquid metal jet; a jet receiver comprised within the vacuum chamber and arranged to receive liquid metal from the liquid metal jet; a first electromagnetic pump section comprising a first inlet and a first outlet, the first inlet having a first diameter; a second electromagnetic pump section comprising a second inlet and a second outlet, and a pumping conduit connecting the second inlet to said second outlet, the pumping conduit having a second diameter; wherein the first outlet is arranged to provide liquid metal to the second inlet. The first diameter is at least 1.8 times as large as the second diameter. A corresponding method is also provided.

An arrangement for providing a liquid metal jet in a vacuum environment is provided. The arrangement comprises a vacuum chamber; a nozzle arranged to provide the liquid metal jet; a jet receiver comprised within the vacuum chamber and arranged to receive liquid metal from the liquid metal jet; a first electromagnetic pump section comprising a first inlet and a first outlet, the first inlet having a first diameter; a second electromagnetic pump section comprising a second inlet and a second outlet, and a pumping conduit connecting the second inlet to said second outlet, the pumping conduit having a second diameter; wherein the first outlet is arranged to provide liquid metal to the second inlet. The first diameter is at least 1.8 times as large as the second diameter. A corresponding method is also provided.

An electrohydrodynamic (EHD) pump increases refrigerant flow rate and the resulting pressure in a vapor compression based cooling system for permitting reduced compressor sizes and power demands. The EHD pump disposes electrodes in a liquid path of the refrigerant flow, and increases fluid flow and resulting pressure by an induced liquid flow between a pair of asymmetric electrodes. Voltage applied to these electrodes results in a conduction pumping mechanism associated with heterocharge layers in the vicinity of the electrodes based on disassociation of a neutral electrolyte species in the refrigerant fluid and recombination of the generated ions. The induced flow draws the liquid due to a net fluid flow toward one of the electrodes based on the asymmetry of the electrode pair. Electrodes are disposed on an inner surface of a refrigerant vessel, in communication with an annular liquid film that forms around the inner circumference in two-phase fluid systems.