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The deployer uses a voice coil actuator (VCA) to control precisely the separation velocity of CubeSats with different masses. This article proposes a novel VCA with a new structure of double magnetic circuits featuring high thrust density. Unlike the conventional design, the new design achieves high thrust density by using a new structure of double magnetic circuits to concentrate the magnetic flux in the airgap and alleviate the magnetic saturation in the yoke. An improved equivalent magnetic circuit is developed to reveal the performance improvement of the novel VCA. The electromagnetic characteristics of the new VCA are investigated and compared with the conventional counterparts by finite element analysis and experimental tests. One VCA deployer prototype has been fabricated and testedexperimentally to validate the thrust density and separation characteristics. [ABSTRACT FROM AUTHOR]

A new type magnetic harmonic gear is proposed. The new magnetic gear has the stackable structure and is assembled easily. The proposed magnetic gear has stacked ring magnets and thin iron plates for the inner and outer rotors. And the two types of the inner and the outer rotors are compared. The proposed magnetic gears can transmit the maximum transmitted torque over 1 Nm and the input rotational speed exceeding 2000 rpm. Furthermore, the influence of a stack on the maximum transmit torque is revealed through the experiment. Also the maximum transmitted torque is checked through the simulations. [ABSTRACT FROM AUTHOR]

To date, the majority of artificial hearts have been nonpulsatile types. Natural hearts, however, are pulsatile, and the long-term biocompatibility of the nonpulsatile types has not been confirmed. We set out to develop a magnetic pump with a pulsatile flow. Because it is pulsatile, we were able to make this pump as small and compact as a natural heart. It consists of a motor, a bellows, and a permanent magnet. The pulsatile flow artificial heart relies on magnetic force. To determine the basic characteristics of the pump, we measured the flow, pressure and magnetic force. We describe the structure of the pump, it's manufacturing method, and it's principle of operation. The use of the bellows allows us to realize a structure where the fluid chambers and drive are separate. When the pump pulsated at 0.6 [Hz], the rate of flow was 0.618 [l/min]. The differential pressure between inflow and outflow was 3.5 [kPa]. The magnetic attractive force was 243.4 [N] and the magnetic repulsive force was 67.3 [N]. We confirmed that the pump was able to pump water by pulsating steadily. [ABSTRACT FROM AUTHOR]

This paper presents the study of a novel bar-shaped magnetic shielding for magnetoresistive (MR) sensors in current measurement on printed circuit boards (PCB). The main physical principles of the shielding effect were studied by using the analytical model of magnetic flux concentration. Finite element analysis (FEA) simulations were used to simulate the shielding effects with changing geometrical parameters of the bar-shaped magnetic shielding. The dependences of the shielding effect on the parameters of length, width and thickness were analyzed. It shows that these parameters are critical for designing magnetic shielding. This new concept of magnetic shielding for MR sensors in current measurement on PCB was experimentally tested and verified in a laboratory setup. The experimental results verify the feasibility and effect of this novel magnetic shielding for MR sensors. [ABSTRACT FROM PUBLISHER]

Abstract: This paper presents the study of magnetic flux concentration phenomenon of magnetic flux concentrators (MFCs) at the micrometer scale. The main physical principles of magnetic flux concentration were studied by using analytical calculations and finite element method (FEM) simulations. The dependences of achievable maximum magnetic gain on the three critical parameters were analyzed. It shows that material, aspect ratio, and shape are three critical parameters for designing MFCs. Three typical MFCs were designed for magnetoresistive (MR) sensors in applications. The magnetic gain and linear working range of the MFCs were studied and compared. By using the same high-permeability magnetic material (nickel–iron alloy, μ r ≈104−105), the MFCs of different geometries perform differently in magnetic amplification. The T-shaped concentrator shows higher magnetic amplification with magnetic gain G= 56 but comparatively narrower linear working range of 1.6mTesla. The bar-shaped concentrator occupies smaller space and provides 62.5% wider linear working range (2.6mTesla) than the T-shaped concentrator but at the expense of 32.1% smaller magnetic gain (G= 38). In the respect of magnetic gain, the triangle-shaped concentrator (G =51) is comparable with the T-shaped concentrator. It provides a 42.3% wider linear working range (3.7mTesla) than the bar-shaped concentrator. [Copyright &y& Elsevier]

The performance of a flux concentrator using an YBCO oxide superconductor was tested to raise the steady state magnetic field generated by the existing magnet. This concentrator was composed of an outside hollow cylinder and a pair of half cylinders that goes in and out in the outside cylinder. This flux concentrator generated additional magnetic field more than 1.6 T for an applied magnetic field 28 T. [ABSTRACT FROM AUTHOR]