Showing papers on "Solenoid published in 2003"

A tunable optical filter

Abstract: We present the details of a new tunable optical filter, suitable for selecting different bands of wavelength in the UV, visible and IR regions. The filter comprises a ferrofluid-based emulsion cell (emulsion sandwiched between two transparent sheets), a miniature solenoid and a variable direct current source for changing the magnetic field inside the solenoid. By varying the magnetic field, one can tune the filter and select the desired wavelength. We discuss the working principle of the new tunable optical filter with a few examples.

Development of three-dimensional inductors using plastic deformation magnetic assembly (PDMA)

Abstract: On-chip inductors are critical for enabling portable power-efficient wireless communication systems. Existing on-chip spiral inductors based on conventional planar integrated-circuit fabrication technology suffer from substrate loss and parasitics, and have relatively large footprints. In this paper, we discuss the development of two types of on-chip three-dimensional (3-D) inductors-a vertical spiral inductor and a solenoid inductor-by using a 3-D assembly process called plastic deformation magnetic assembly. Prototype vertical spiral inductors and solenoid inductors have been fabricated and tested. Experimental results show that the vertical spiral inductors can achieve better performance and a smaller footprint than the in-plane ones.

The double-helix dipole - a novel approach to accelerator magnet design

Abstract: We describe a new technology for superconducting dipoles that has significant advantages for use in particle accelerators. The dipole field is obtained by using concentric pairs of helically-wound coils that are tilted at opposite angles; this effectively cancels the solenoid component of the field and adds the dipole content of each layer. This coil configuration produces a dipole field with systematic errors <10/sup -8/ of the main field in 85% of the coil aperture. We show, using a design example, how many of the inherent problems with the traditional cosine theta type of coil are eliminated and the cost of development and manufacturing the magnets is substantially reduced.

New procedures for calculating the mutual inductance of the system: filamentary circular coil-massive circular solenoid

Abstract: New and fast procedures for calculating the mutual inductance between a thin circular filament coil and a massive circular solenoid in air are presented. The coils are axisymmetric. These results are expressed over the complete elliptical integrals of the first and second kind, Heumann's Lambda function, and one term that has to be solved numerically. The numerical integration of this term is based on some numerical integrations to get the satisfactory accuracy and computational cost. These new expressions are accurate and simple to apply for useful applications. Also, another comparative method based on an approximation of the massive solenoid by Maxwell's coils is given. The paper discusses the computational cost and the accuracy. Results obtained by the two approaches are in excellent agreement.

Heat pump device

Abstract: PURPOSE: To prevent quantity of a coolant circulating along a coolant circuit from decreasing by providing solenoid valves at the front and rear stages of an evaporator circuit and also providing a control circuit for operating these solenoid valves and carrying out the pumping down of the evaporator circuit on the side not utilized. CONSTITUTION: The heat pump device comprises solenoid valves 14c, 14d, 15c and 15d which are provided respectively at the front stages and the rear stages of evaporator circuits C and D and open and close the evaporator circuits C and D, and a control circuit for operating these solenoid valves and carrying out the pumping down of the evaporator circuit or the side not utilized. According to this structure, during the stoppage of the heat pump device, all the solenoid valves 14c, 14d, 15c and 15d are closed. Therefore, it is possible to reduce the quantity of the coolant moving to evaporators 13c and 13d. Further, at the time of starting the heat pump device, the solenoid valves 14c and 15c of the circuit C of the utilizing side evaporator 13c are closed and the solenoid valves 14d and 15d are opened. Thus, the coolant flows to the evaporator 13d on the side not utilized. After operating for a predetermined time, the solenoid valve 15d is closed, and the solenoid valve 14c and 15c are opened and the evaporator 13d stands still and an operation utilizing the evaporator 13c is carried out. Consequently, the evaporator 13d can recover the stored coolant and the freezer oil. COPYRIGHT: (C)1989,JPO&Japio

Modulated double-helix quadrupole magnets

Abstract: We describe a new technology for superconducting quadrupole magnets especially for use in particle accelerators. The principle is based on the application of a sinusoidal modulation to the axial positions of the conductor windings in solenoids. The method can also be employed to produce higher-order multipole fields. Due to their solenoid-like geometry, these coils are significantly simpler to manufacture than standard (racetrack) cosine-2-theta coils and have significantly smaller systematic field errors without using any field-shaping spacers. When two complementary coil layers (with opposite current flow) are combined, the solenoid components of the fields are cancelled and the quadrupole or higher-order fields add. An example of such a design is described which generates a gradient of 130 T/m with systematic errors less than 10/sup -8/ at 67% of the aperture.

Integrated control unit for an active roll control system for a vehicle suspension system

Abstract: An Active Roll Control System for a motor vehicle that utilizes small valves to control large flows. Flow is supplied by a hydraulic pump which is powered in some fashion by the motor vehicle. Flow is directed to the actuators by a three­position four-way valve that is controlled by two pairs of small ABS style solenoid valves. This allows for a minimum of power to be supplied by the vehicle to operate the system. Also, this valve arrangement allows a desirable failure mode whereby hydraulic fluid is locked into the hydraulic actuators, there by locking in the anti-roll bar in case of a system failure.

Test of the ITER TF insert and Central Solenoid Model Coil

Abstract: The Central Solenoid Model Coil (CSMC) was designed and built by ITER collaboration between the European Union, Japan, Russian Federation and the United States in 1993-2001. Three heavily instrumented insert coils have been also built for testing in the background field of the CSMC to cover a wide operational space. The TF Insert was designed and built by the Russian Federation to simulate the conductor performance under the ITER TF coil conditions. The TF Insert Coil was tested in the CSMC Test Facility at the Japan Atomic Energy Research Institute, Naka, Japan in September-October 2001. Some measurements were performed also on the CSMC to study effects of electromagnetic and cooldown cycles. The TF Insert coil was charged successfully, without training, in the background field of the CSMC to the design current of 46 kA at 13 T peak field. The TF Insert met or exceeded all design objectives, however some interesting results require thorough analyses. This paper presents the overview of main results of the testing - magnet critical parameters, joint performance, effect of cycles on performance, quench and some results of the post-test analysis.

Transport critical current of solenoidal MgB2/Cu coils fabricated using a wind-reaction in situ technique

Abstract: In this letter, we report the results on transport Jc of solenoid coils of up to 100 turns fabricated with Cu-sheathed MgB2 wires using a wind-reaction in situ technique Despite the low density of the single core and some reaction between the Mg and Cu sheaths, our results demonstrate that the decrease in transport Jc with increasing length of MgB2 wires is insignificant Solenoid coils with diameter as small as 10 mm can be readily fabricated using a wind-reaction in situ technique The Jc of the coils is essentially the same as that of comparable straight wires A Jc of 133000 A cm−2 and 125000 A cm−2 at 4 K and self-field has been achieved for a small coil wound using Cu-sheathed tape and Cu-sheathed wire, respectively These results indicate that MgB2 wires have a great potential for large-scale applications

Superconducting double-helix accelerator magnets

Abstract: We describe an important contribution to accelerator magnet technology based on the concept of modulating the helical turns of solenoid coils to produce pure multipole fields of any order. Calculations show that these configurations inherently produce virtually error free fields of the desired multipole order in a large fraction of the aperture in the two dimensional cross section without the presence of iron. The characteristics of one such configuration, the double-helix dipole (DHD), are described. It is also explained how the novel geometry of the double-helix coils simplifies the manufacturing, eliminates complex coil parts, and thus significantly reduces the cost of the magnets in comparison to the conventional cosine theta (racetrack design) coils. This has been demonstrated by the design and construction of a prototype dipole that produces a 4T field in an 80 mm aperture (without iron).

Cylindrical Penning trap for the study of electron plasmas

Abstract: The ELTRAP device installed at the Department of Physics of the University of Milan is a Malmberg–Penning trap, with a magnetic field up to 0.2 T, equipped with charge coupled device optical diagnostics. It is intended to be a small scale facility for electron plasma and beam dynamics experiments, and in particular for the study of collective effects, equilibrium states, and the formation of coherent structures in these systems. The device features a relatively long solenoid, corrected by 4 shims and 16 dipole coils, in order to obtain a large uniform magnetic field region. The modular electrode design allows several variations of the experimental configuration. The first experiments which assess the operation of the facility are described. Plasma confinement times up to several minutes have been obtained and an electron temperature of 4–8 eV has been measured.

Experimental study of a new kind of superconducting inductor

Abstract: Electrical motors need a spatial variation of the flux density created by their inductors to make torque. We propose to achieve this angular repartition of the induction with bulk high temperature superconducting plates and two low temperature superconducting solenoids. These solenoids have the same axis and are fed with opposite currents in order to create a radial magnetic induction. Four superconducting plates placed on the cylindrical surface, situated on the same axis and having the same radius as the solenoids, concentrate the magnetic field. This device provides a spatial variation of the flux density, and can be considered as an inductor for a synchronous motor with eight poles. This paper presents the experimental study of our prototype at 4.2 K. We compare the experimental results with calculation. Ten Hall probes permit us to reconstitute the angular variation of the flux density. The paper shows the feasibility of this new kind of superconducting inductor.

Variable-period undulators as synchrotron radiation sources.

Abstract: A concept for variable-period undulators for the production of synchrotron radiation from both medium- and high-energy storage rings is described. This concept is based on a staggered array of permeable poles placed in a magnetic solenoid that produces a longitudinal field. The concept permits variations in the short magnetic period of the undulator of as much as 100%. The unique capabilities of such undulators will allow them to be tuned by the variation of the period length and of the solenoid field. The device can be operated at either constant flux or constant power, independent of X-ray energy. It is expected that the new concept will have a major impact on the production and applications of X-rays because of the inherent simplicity and flexibility of the design and the absence of radiation damage. Analyses of the magnetic and mechanical design concepts are presented.

Magnetic latching solenoid

Abstract: A magnetic latching solenoid including a solenoid operating mechanism, and further comprising a magnetic latching subassembly cooperating with, but positioned independently of the solenoid operating mechanism. In a preferred embodiment, the solenoid operating system may be of a bi-directionally operated structure arranged for alternative magnetically latching function. Independently operated, magnetic latching subassemblies are spaced apart from one another and from opposite ends of the bi-directionally operated solenoid operating mechanism.

A study on the numerical analysis of magnetic flux density by a solenoid for magnetically impelled arc butt welding

Abstract: The magnetically impelled arc butt (MIAB) welding process uses a rotating arc as its heat source and is known as an efficient method for pipe butt welding. The arc in the gap of the pipe butt joints is rotated along the circumferential weld line by the electromagnetic force resulting from the interaction of the arc current and the magnetic field in the gap. The electromagnetic force is determined by the magnetic flux density in the gap, the arc current and the arc length (i.e. gap size). In particular, the radial magnetic flux density is an important factor in arc rotation and weld quality.This paper proposes a two-dimensional finite element model for the analysis of magnetic flux density distributions in the MIAB welding process. The magnetic flux density is mainly dependent on the gap size between two pipes, the position of the exciting coil that generates the magnetic field, the exciting current in the coil, and the relative permeability of the pipes. Thus, the relations between the magnetic fl...

Apparatus and method for monitoring and compensating for variation in solenoid resistance during use

Abstract: A very small fixed current is passed through the coil of a solenoid during use thereof when the solenoid is in its “off” state of cyclic PWM command, the fixed current being less than the current required to actuate the solenoid to the “on” position. While the current is flowing through the coil, the voltage across the coil is measured. The resistance of the coil is calculated according to Ohm's Law. When the actual resistance is known, the duty cycle imposed on the solenoid may be altered to compensate for the resistance deviation from nominal. This allows, for example, fuel injectors for internal combustion engines to deliver the correct amount of fuel under all operating conditions.

Fuel-injection control method and fuel-injection control device

Abstract: In order to perform accurate fuel injection control in response to fuel injection requests from the engine side without being affected by variations in power supply voltage and in coil temperature of a fuel injection solenoid and by other external factors, driving of the fuel injection solenoid is controlled based on the actual current integral of the coil current flowing through the solenoid after starting driving the solenoid. More specifically, the present invention provides a fuel injection control method having the steps of starting driving of a fuel injection solenoid, detecting an actual current integral of a coil current that flows through the solenoid after starting the driving of the solenoid, comparing the actual current integral with a reference current integral beforehand set in relation to a driving pulse width for the solenoid corresponding to a required fuel injection amount, and correcting the driving pulse width for the solenoid based on comparison between the actual current integral and the reference current integral, where the driving of the solenoid is controlled based on the corrected driving pulse width.

Electromagnetic clutch assembly having solenoid type operator

Abstract: An electromagnetic clutch assembly having a solenoid activated ball ramp operator provides reduced power consumption and improved control. The electromagnetic clutch assembly includes a primary or pilot friction clutch pack and a secondary or main friction clutch pack. An annular solenoid coil cooperates with an annular operator or plunger. When the coil is energized, the annular plunger translates and compresses the primary or pilot friction clutch pack. Activation of the pilot clutch pack retards motion of one of the members of the ball ramp operator which, in turn, compresses a secondary or main friction clutch pack disposed across the input and output members.

Portable air compressor/tank device

Abstract: A portable, low cost air supply device for accumulating and dispensing compressed air converted from photovoltaic energy. The device includes one or more photovoltaic cells, a capacitor, an electronic trigger device, a solenoid, a valve manifold, a reservoir, and a device for dispensing accumulated air. The photovoltaic cell(s) charge the small, low cost capacitor. When saturated, the capacitor is triggered by a solid-state device to discharge the electrical charge to a solenoid. The energized solenoid then extends its plunger into a hole in the valve manifold, compressing air into the manifold. The compressed air moves past a check valve, and into a storage reservoir. The solenoid rapidly de-energizes, the plunger retracts, and the solenoid is now ready for another compression stroke.

Method of calibrating a solenoid operated pressure control valve and method of controlling same

Abstract: A method of calibrating a solenoid operated pressure control valve by sweeping the solenoid with increasing current from a minimum to a maximum and measuring and recording the signal pressure output and current at selected increments of current and storing the data pairs in a first table. The solenoid is similarly swept with decreasing current from the maximum to a minimum and the signal output pressure measured at selected increments of current and the data pairs stored in a second table. Upon installation of the valve in an hydraulic system to be controlled, the commanded signal pressure output P c , if greater than the instantaneous signal pressure output P 2 is compared with the closest data pairs in the first table and, by interpolation, the required solenoid energization current I e determined. If the commanded signal pressure output P c is less than the instantaneous signal pressure P 2 is compared with the closest data pair in the second table and, by interpolation, the required solenoid energization current I e determined.

Connector with inductive coupling

Abstract: The inductive coupling for transferring electrical energy to or from a transducer and measuring circuit, consists of a male connector part (2) and a female connector part (10). The male part (2), includes a single layer solenoid (7) wound on a ferromagnetic rod (6), the ends of the solenoid (5a and 5b) connected to conductors (3a and 3b) connected to an ultrasound probe (not shown) via cable (1). The female part (10) includes a single layer solenoid (11). The ends of solenoid (11) are brought out to terminals (12a and 12b) to facilitate electrical connection to the ultrasound drive electronics (not shown). The coupling provides a simple sealed signal connection between the cable connected with the transducer and the measuring circuit electronics without the disadvantages of having exposed contact surfaces. The cable connector can be replaced if desired.

Test of the NbAl insert and ITER central solenoid model coil

Abstract: The Central Solenoid Model Coil (CSMC) was designed and built by an ITER collaboration in 1993-2001. Three heavily instrumented Inserts have been also built for testing in the background field of the CSMC. The Nb/sub 3/Al Insert was designed and built by Japan to explore the feasibility of an alternative to Nb/sub 3/Sn superconductor for fusion magnets. The Nb/sub 3/Al Insert coil was tested in the CSMC Test Facility at the Japan Atomic Energy Research Institute, Naka, Japan in March-May 2002. It was the third Insert tested in this facility under this program. The Nb/sub 3/Al Insert coil was charged successfully without training in the background field of the CSMC to the design current of 46 kA at 13 T peak field and later was successfully charged up to 60 kA in 12.5 T field. This paper presents the test results overview.

Inductively coupled rf coils for examinations of small animals and objects in standard whole-body MR scanners.

Abstract: Inductively coupled solenoid coils fitting to objects in the size of mice or rats were developed to adapt modern whole-body MR scanners featuring sufficient gradient strength for animal examinations with high spatial resolution. Homogenous receiver characteristics is achievable over almost the whole inner region of the solenoid coils. The SNR can be increased by a factor 2 to 6 with the adapting coils for examinations using the head coil as connected receiver. Standard sequences on clinical 1.5 T scanners can be applied with adapted transmitter voltages. For example, a SNR value of about 30 is achievable in a mouse liver after 10 minutes measuring time using a 2-D spin echoimaging sequence and a size of 0.3×0.3×0.8 mm 3 for the picture elements.

PHENIX magnet system

Abstract: The PHENIX magnet system is composed of three spectrometer magnets with warm iron yokes and water-cooled copper coils. The Central Magnet (CM) is energized by two pairs of concentric coils and provides a field around the interaction vertex that is parallel to the beam. This allows momentum analysis of charged particles in the polar angle range from 70° to 110°. The north and south Muon Magnets (MMN and MMS) use solenoid coils to produce a radial magnetic field for muon analysis. They each cover a pseudorapidity interval of 1.1–2.3 and full azimuth. The coils are wound on cylindrical surfaces at the end of large tapered pistons. Each of the three magnets provides a field integral of about 0.8 T -m. The physical and operating parameters of the magnets and their coils are given along with a description of the magnetic fields generated. The geometric, thermal and magnetic analysis leading to the coil design is discussed. The magnetic volumes of the PHENIX magnets are very large and complex, so a new technique was developed to map the fields based on surface measurements of a single field component using single axis Hall probes mounted on a rotating frame. A discussion of the performance of the CM during the first year of PHENIX running is given.

Hydraulic brake device

Abstract: A hydraulic brake device includes a master cylinder supplying pressurized fluid to plural brakes which respectively restrict the rotations of road wheels, a solenoid block mounted on the master cylinder and containing plural solenoid valves, and an ECU provided with a control board for controlling the solenoid valves to distribute pressurized fluid to the plural brakes and also provided with a case for containing the control board therein. The solenoid block and the ECU form an integrated structure, and the integrated structure composed of the solenoid block and the ECU is removably mounted on the master cylinder. Further, the ECU is secured to the solenoid block by screw bolts which are arranged within an area inside the external form of the control board. Thus, it becomes unnecessary to provide bolt seats for the screw bolt outside the case.

Performance of a Low-Density Hypersonic Magneto-Aerodynamic Facility

Abstract: : A hypersonic, weakly ionized gas experimental facility has been successfully developed for magnetoaerodynamics basic research. The weakly ionized air is generated by a combination of direct current discharge, radio frequency discharge, and a combination of both in a blow-down, open jet, Mach 5 flow channel. The plasma field is characterized by electron temperatures around 10,000 K, and electron number density up to 2x10(exp 12) cu cm. The magnetic field is provided by a steady sate solenoid that can generate a maximum field up to three Tesla and an array of permanent magnets. In this environment, the maximum ma magneto-aerodynamic interaction parameter per unit length is around 1.5 per meter. A collection of plasma diagnostic tools including emission spectroscopy, microwave absorption, and Langmuir probes also are available.

Compact linear air pump and valve package

Abstract: A compact air pump and valve package includes pump and valve assemblies integral with a pressure housing defining inlet ports and a plurality of fittings for connecting air lines to an interior of the pressure housing The linear diaphragm pump assembly has a permanent magnetic shuttle mounting two diaphragms reciprocated by an electromagnet The valve assembly has a plurality of solenoid valves disposed within the pressure housing, each solenoid valve being operable to control flow into or out of the pressure housing through an associated one of the plurality of fittings Thus, no tubes or hoses are required to transfer air from the pump assembly to the valves The housing has special mounts to isolate vibration arising from movement of the shuttle

Fuel supply system

Abstract: PROBLEM TO BE SOLVED: To provide a fuel supply system capable of carrying out diagnosis and protection of the fuel supply system. SOLUTION: This fuel supply system is provided with a means for detecting an operating condition of an engine, a means for calculating the width of a fuel injection pulse consisting of a valve opening signal and a holding signal on the basis of the detected operating condition, a means for supplying a valve opening current to a solenoid provided for a fuel injection equipment on the basis of the calculated width of the fuel injection pulse, and a means for supplying a holding current that holds a valve opening condition to the solenoid when the valve opening current reaches a specified current value. When logical multiplication of the valve opening signal and the holding signal is achieved, an electric current is supplied to the solenoid. Moreover, when the time from the moment of starting the fuel injection pulse until the valve opening current reaches the specified current value is shorter than a specified time, abnormality judgement of the fuel injection equipment is conducted. COPYRIGHT: (C)2004,JPO