749 results about "Critical current" patented technology

A surgical instrument includes a surgical end effector having at least one actuation assembly to effect a surgical procedure when actuated, an electric motor operationally connected to the end effector to operate the at least one actuation assembly, and a power supply electrically connected to the motor and selectively powering the motor to actuate the actuation assembly. The power supply has a battery cell with a critical current rate and, when activated to power the motor and actuate the actuation assembly, operates the cell at a super-critical current rate or at an average current rate above the critical current rate. The power supply selectively powers the motor to actuate the assembly less than 16 times during a clinical life of at least one of the end effector, the motor, and the power supply. When actuated, the assembly operates only between 0.5 seconds and 16 seconds in duration.

We describe the structure and method of forming a STT-MTJ MRAM cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a free layer that comprises an amorphous layer of Co₆₀Fe₂₀B₂₀. of approximately 20 angstroms thickness formed between two crystalline layers of Fe of 3 and 6 angstroms thickness respectively. The free layer is characterized by a low Gilbert damping factor and by very strong polarizing action on conduction electrons. The resulting cell has a low critical current, a high dR/R and a plurality of such cells will exhibit a low variation of both resistance and pinned layer magnetization angular dispersion.

A magnetic random access memory device comprises a spin torque MRAM cell (100) having a reduced switching current (I_c) wherein standard materials may be used for a free layer (108). A fixed magnetic element (112) polarizes electrons passing therethrough, and the free magnetic element (108) having a first plane anisotropy comprises a first magnetization (130) whose direction is varied by the spin torque of the polarized electrons. An insulator (110) is positioned between the fixed magnetic element (112) and the free magnetic element (108), and a keeper layer (104) positioned contiguous to the free magnetic element (108) and having a second plane anisotropy orthogonal to the first plane anisotropy, reduces the first plane anisotropy and hence reduces the spin torque switching current (I_c). The keeper layer (104) may comprise alternating synthetic antiferromagnetic layers (132, 134) of magnetization approximately equal in magnitude and opposite in direction.

A magnetic memory cell comprises in-plane anisotropy tunneling magnetic junction (TMJ) and two fixed in-plane storage-stabilized layers, which splits on the both side of the data storage layer of the TMJ. The magnetizations of the said fixed in-plane storage-stabilized layers are all normal to that of the reference layer of TMJ but point to opposite direction. The existing of the storage-stabilized layers not only enhances the stability of the data storage, but also can reduce the critical current needed to flip the data storage layer via some specially added features.

A surgical instrument includes an end effector having an actuation assembly to effect a surgical procedure when actuated. An electric motor has a rated operating voltage and is operationally connected to the end effector to operate the actuation assembly. A power supply is electrically connected to the motor and selectively powers the motor to actuate the actuation assembly at least 1 and less than 16 times during a clinical life of at least one of the end effector, the motor, or the power supply. The power supply has a battery cell with a critical current rate. When activated to power the motor and actuate the actuation assembly, the power supply operates the battery cell at a super-critical current rate during a non-zero super-critical pulse discharge period lasting less than approximately 16 seconds. The power supply operates the motor above the rated operating voltage during the super-critical pulse discharge period.

A method for depositing uniform and smooth ferromagnetic thin films with high deposition-induced microstructural anisotropy includes a magnetic material deposited in two or more static oblique deposition steps from opposed directions to form a free layer having a high kink Hk, a high energy barrier to thermal reversal, a low critical current in spin-torque switching embodiments, and improved resistance to diffusion of material from adjacent layers in the device. Nonmagnetic layers deposited by the static oblique deposition technique may be used as seed layers for a ferromagnetic free layer or to generate other types of anisotropy determined by the deposition-induced microstructural anisotropy. Additional magnetic or non-magnetic layers may be deposited by conventional methods adjacent to oblique layer to provide magnetic coupling control, reduction of surface roughness, and barriers to diffusion from additional adjacent layers in the device.

A method of programming electrical fuses reliably is disclosed. If a programming current exceeds a critical current, disruptive mechanisms such as rupture, thermal runaway, decomposition, or melt, can be a dominant programming mechanism such that programming is not be very reliable. Advantageously, by controlled programming where programming current is maintained below the critical current, electromigration can be the sole programming mechanism and, as a result, programming can be deterministic and very reliable. In this method, fuses can be programmed in multiple shots with progressive resistance changes to determine a lower bound that all fuses can be programmed satisfactorily and an upper bound that at least one fuse can be determined failed. If programming within the lower and upper bounds, defects due to programming can be almost zero and, therefore, defects are essentially determined by pre-program defects.

A superconducting current limiting element has a parallel circuit including a first superconductor and a normal conductor connected in parallel, and a second superconductor connected in series to the parallel circuit and having a critical current value higher than that of the first superconductor. Further, at least one of the normal conductor and the first superconductor, and the second superconductor are disposed on the same insulating substrate.

Embodiments of a method of copper plating a substrate surface with a group VIII metal layer have been described. In one embodiment, a method of plating copper on a substrate surface with a group VIII metal layer comprises pre-treating the substrate surface by removing a group VIII metal surface oxide layer and/or surface contaminants and plating the substrate in a copper plating solution comprising about 50 g/l to about 300 g/l of sulfuric acid at an initial plating current higher than the critical current density to deposit a continuous copper layer on the substrate surface. The Pre-treating the substrate can be accomplished by annealing the substrate in an environment with a hydrogen-containing gas environment and/or a non-reactive gas(es) to Ru, by a cathodic treatment in an acid-containing bath, or by immersing the substrate in an acid-containing bath.

Superconducting single flux quantum circuits are disclosed herein, each having at least one Josephson junction which will flip when the current through it exceeds a critical current. Bias current for the Josephson junction is provided by a biasing transformer instead of a resistor. The lack of any bias resistors ensures that unwanted power dissipation is eliminated.

An EP output voltage to be outputted during a period of EP polarity is set so that a welding current becomes equal to or lower than a critical current level, and an EN output voltage to be outputted during a period of EN polarity is set at a level lower than the EP output voltage. This makes it possible to substantially equalize a wire melting rate in the period of EN polarity and that in the period of EP polarity with each other. Even at such a short arc length as causing frequent short circuiting, gas-shielded AC arc welding making use of a consumable wire can be still performed stably so that high wire melting rate, shallow penetration, convex weld reinforcement and the like, which are characteristic features of AC welding, can each be set selectively at a desired level or in a desired shape depending on the application.

A superconducting wire includes first and second superconducting layers disposed on one or more substrates in stacked relationship, the first superconducting layer comprising a high temperature superconducting oxide of a first composition and the second superconducting layer comprising a high temperature superconducting layer of a second composition, wherein the first and second compositions are different. The first superconductor layer optionally includes a high temperature superconductor composition selected to provide enhanced critical current (Ic(c)) in the presence of magnetic fields perpendicular to surface of the superconducting layer (H//c). The second superconductor layer optionally includes a high temperature superconductor composition selected to provide enhanced critical current (Ic) in the presence of magnetic fields parallel to surface of the superconducting layer (H//ab).

Disclosed are an apparatus and method for estimating the power of a secondary battery including a blended cathode material. The apparatus according to the present disclosure includes a sensor configured to measure a discharge current of a secondary battery comprising a cathode including a blended cathode material, and a control unit configured to estimate a state of charge of the secondary battery, determine a discharge voltage of the secondary battery using a first resistance predefined corresponding to the state of charge under a first condition in which a magnitude of the discharge current is smaller than a magnitude of a critical current and a second resistance predefined corresponding to the state of charge under a second condition in which the magnitude of the discharge current is larger than the magnitude of the critical current, and determine the power of the secondary battery from the determined discharge voltage and the measured discharge current.

The invention discloses a preparation method for an NbTi/Cu multi-core composite superconducting wire with a rectangular section, which comprises the following steps of: firstly, assembling an NbTi bar, a pure Nb inner pipe and an oxygen-free copper sheath in turn to form an NbTi/Cu composite sheath, sealing an upper end cap and a lower end cap of the NbTi/Cu composite sheath through vacuum welding, and then performing primary extrusion to obtain an NbTi/Cu composite bar; secondly, drawing and scaling the composite bar, and keeping on drawing the composite bar to obtain a hexagonal core rod, and performing assembling for the second time; and thirdly, performing vacuum solder sealing, hot isostatic pressing, secondary extrusion, bar drawing and scaling on the sheath which is assembled in the second time to finally obtain the NbTi/Cu multi-core composite superconducting wire with the rectangular section. The preparation method has the advantages of simple process flow, low preparation cost and good preparation effect, improves the fill factor among windings in the process of coiling a superconducting magnet but simultaneously keeps high critical current density for the wire, and overcomes the defects that the conventional four-high mill or forming roll mill is unevenly stressed, is difficult to process and the like in the rolling process.

This invention concerns an improvement of the supercurrent carrying capabilities, i.e. the increase of critical current densities, of polycrystalline superconductor structures, especially of high-T_c superconductors fabricated with a coated conductor technique to provide superconducting layers containing flat grains. A superconductor with superior critical current density is obtained by joining, i.e. pressing or otherwise bringing into intensive facial contact, preferably superconducting contact, two or more such superconducting layers.

Electrical connection of superconducting lines can be achieved by using a low-melting point metal, by mechanical contact of superconducting lines or by welding. According to these methods, however, critical current and critical magnetic field at the connection point are low, and stable connection in a superconducting state has been difficult. The present invention solves these problems and provides a structure and method for connecting superconducting lines. The present invention provides high-performance, high-stability connection of superconducting lines through magnesium diboride (MgB₂) powder arranged between superconducting lines.