Showing papers on "Solenoid published in 1998"

Method for near field electromagnetic proximity determination for guidance of a borehole drill

Abstract: A method and apparatus for precise measurement of the distance and direction from a magnetic field sensor to a nearby magnetic field source includes an elongated iron core solenoid driven by a repetitive, nonsinusoidal current source. In the near field the solenoid has two spaced, temporally varying magnetic poles, and measurement of the distance and direction to this source includes analysis of field components which vary in synchronism with the current source.

Surface micromachined solenoid inductors for high frequency applications

Abstract: As operation frequencies and performance requirements of wireless devices increase, the resultant demands on the performance of passive components also increase. Miniaturization of inductive components for high frequency has been a key research area to address this issue; however, in general, miniaturized integrated inductors can suffer from low Q factors and/or self-resonant frequencies when compared to their discrete counterparts. In this research, a modified geometry of a solenoid type inductor using a surface micromachining technique is proposed. This inductor has an air core and an electroplated copper coil to reduce the series resistance, and its low temperature process is suitable for various packaging applications. An important feature of the proposed inductor geometry is the introduction of an air gap between the substrate and the conductor coil in order to reduce the effects of the substrate dielectric constant. This air gap can be realized using a polyimide sacrificial layer and a surface micromachining technique. Therefore, the resulting inductor can have less substrate-dependent magnetic properties, less stray capacitance, and higher Q-factor. The measurement result shows that this inductor has high Q-factor and stable inductance over a wide range of operating frequency. Also, various effects of geometrical factors have been investigated. Various inductors with the inductance varying from 1 to 20 nH and maximum Q-factor from 7 to 60 have been fabricated and measured.

Articulated magnetic guidance systems and devices and methods for using same for magnetically-assisted surgery

Abstract: An articulated magnet assembly optionally includes one or two additional fixed magnets to guide or move such as by pulling or pushing a magnetic structure in the body. The magnetic structure may be a magnetic tip of a catheter or a magnetic seed, or other such magnetic assembly, implant or device. The device is arranged to facilitate biplanar, real-time, X-ray imaging of the patient. The moved magnet can be a large, strong permanent magnet or a cored solenoid. The added, fixed electromagnets may have either normally conducting or superconducting coils. The magnet on the articulated magnet assembly can move radially, along a polar direction, and at an azimuthal angle, and may also pivot in place to direct an opposite pole of the magnet in the direction of the patient. Magnetically-assisted surgery can be performed, in some instances, by pivoting the magnet on one or two axes without withdrawing it from the vicinity of the patient to control the direction and/or orientation of a temporarily or permanently implanted magnetic surgical device. If the magnet is an electromagnetic coil, this pivoting may or may not have to be accompanied by a ramping of current in the coil.

Pneumatic lumbar adjustment system

Abstract: A pneumatic lumbar adjustment system for a vehicle seat includes an inflatable bladder, a pump and a solenoid valve, all of which are mounted on a backing plate which is secured to the back frame of the seat in the lumbar region. The pump and solenoid valve are connected to the vehicle electrical system through a three way switch accessible to the seat occupant through a two terminal lead. One switch position is the "off" position in which power to both the pump and the solenoid valve are turned off, and the other two positions are actuated positions, but in which one actuated position reverses the polarity of the terminals. In one of the actuated positions, power is supplied to the pump and the solenoid, causing the bladder to inflate. In the other actuated position in which the polarity of the terminals are reversed, power is supplied only to the solenoid valve and not to the pump, causing the solenoid valve to exhaust air from the bladder. Since inflation and deflation of the bladder may be stopped at any time by the occupant merely moving the switch to the off position, the desired amount of lumbar support may be selected.

Electronic lock in cylinder of standard lock

Abstract: An electronic security system includes an electronic lock mechanism and an electronic key, each of which is provided with a microprocessor controller and a memory storing data including an ID code and encryption key codes. The lock microprocessor may either change ID codes stored in its memory or encrypt a seed number to be used for determining access to the lock. The key can only be used to access the lock either once or for a limited number of successive times, and must thereafter be reprogammed by a host computer to be loaded with either the proper ID code or the appropriate encryption key code for that lock. An electornic lock security system preferably includes an electronic lock including a hollow cylinder, an opening into the cylinder, a bolt movable through the opening between an extended position and a retracted position, a cam member within the cylinder, the cam member contacting the bolt to move the bolt to an unlocked position, a solenoid within the hollow cylinder, the solenoid being engageable with the cam member, an electronic lock circuit within the hollow cylinder, a plug connected to the solenoid for rotating the solenoid, the plug having a keyway for insertion of key means for rotating the plug. In addition, the system also includes a key means insertable within the keyway and having electronic means for communicating with the electronic lock circuit to operate the lock. The solenoid is a novel torque transmitting solenoid that can also be used in a variety of other environments.

Method and device for fuel injection of engine

Abstract: In the fuel injection method and device for engines, information obtained from the differential value of the common rail pressure is used to correct the parameters of the command pulses to the flow control valve and the solenoid valve of each injector and thereby limit deviations of the fuel injection characteristic of the injector from the target injection characteristic. From the curves of the differential values R of the common rail pressure Pc, the actual fuel injection parameters for the injectors-injection start timing Tis, gross injection amount Qt, initial injection amount Qe and maximum injection rate Rmax-are obtained. The command pulse output timing (PTpf, PTif) for the flow control valve, which controls the amount of fuel delivered from the fuel pump, and for the solenoid valve of each injector and the gross or initial command pulse width (PWit, PWief) for the solenoid valves of each injector are controlled so that the above parameters agree with the target injection characteristic determined from the corresponding operating states of the engine.

Status report on a dc 130 mA, 75 keV proton injector (invited)

Abstract: A 110 mA, 75 keV dc proton injector is being developed at Los Alamos A microwave proton source is coupled to a two solenoid, space-charge neutralized, low-energy beam transport (LEBT) system The ion source produces 110 mA proton current at 75 keV using 600–800 W of 245 GHz discharge power Typical proton fraction is 85%–90% of the total extracted ion current, and the rms normalized beam emittance after transport through a prototype 21 m LEBT is 020 (πmm mrad) Beam space-charge neutralization is measured to be >98% which enables the solenoid magnetic transport to successfully match the injector beam into a radio-frequency quadrupole Beam simulations indicate small emittance growth in the proposed 28 m low-energy demonstration accelerator LEBT The LEBT also contains beam diagnostics, steering, and a beam deflector for variable duty factor and accelerator fast protect functions The injector beam availability status is also discussed

Proportional variable force solenoid control valve with armature damping

Abstract: Proportional variable force solenoid valve for controlling the pressure of a fluid in a fluid control system comprises a solenoid housing having therein a solenoid coil, an armature movable in response to electrical current applied to the solenoid coil, and a biasing spring for biasing the armature in a direction to establish a valve fluid pressure response to solenoid coil current. An inner armature end cooperates with or engages a damping member residing in a fluid damping chamber to reduce non-linear valve responses resulting from pressure oscillations in the fluid control system.

Latching solenoid valve

Abstract: A pilot valve is operated by solenoid formed by a coil (52) wound around a non-magnetic spool that has a bore (56). A rare earth permanent magnet (62) is inside the bore adjacent one end and abuts a flux concentrator (58) farther inside the bore. A plunger (68) is slidably located within the bore biased away from the flux concentrator by a spring (70) and projects out another end of the bore. An enclosure of magnetic material completes a magnetic flux path around the solenoid and has an aperture through which the plunger projects. The pilot valve includes a cage (86) of rigid non-magnetic material which abuts the enclosure and has a recess which supports the plunger out of contact with the housing. The plunger selectively opens and closes a pilot tube (92) through the cage to operate a diaphragm (100) that responds by engaging a primary valve seat to control the flow of fluid through a valve body.

Monolithic Fabrication of Electroplated Solenoid Inductors Using Three-Dimensional Photolithography of a Thick Photoresist

Abstract: A novel and high-yield fabrication process has been devised for monolithic integration of solenoid inductors. In order to simplify the fabrication steps, we decompose the solenoid inductor into two parts, bottom conductor lines and air bridges. The air bridge is formed as a single body during a single electroplating step. This single-step fabrication of the air bridges is possible by forming a three-dimensional (3D) photoresist mold using multiple exposures with varying exposure depths, followed by a single development step, which realizes the 3D latent image of the unexposed volume in the photoresist. We have successfully fabricated solenoid inductors with and without a magnetic core using this process. This process is easy and simple, so that one can significantly improve the fabrication yield over that achieved by conventional methods. Also, this process has good compatibility with the integrated circuit (IC) process owing to a low process temperature (<120°C) and the monolithic feature.

Solenoid pressure transducer

Abstract: A solenoid pressure transducer for measuring and controlling pressure within a system includes pressure sensing technology incorporated into a solenoid valve such that a common pressure chamber is used to sense pressure of a fluid and to control the flow of the same fluid. A solenoid sleeve forms the pressure chamber and a sensing element attached to the sleeve is used to measure pressure within the sleeve. The pressure measurement is then used by the solenoid sleeve to control the position of the solenoid valve.

Locating an inaccessible object by detecting horizontal and vertical components of a magnetic field

Abstract: If a solenoid is mounted on an underground object, such as a boring tool, magnetic fields generated by an electric current flowing through that solenoid can be detected by a suitable detector at or above the surface If the axis of the solenoid is tilted, the maximum value of the field is not directly above the solenoid Therefore, the present invention makes use of measured values of horizontal and vertical components of the magnetic field to determine the separation of the detector and the solenoid, and also, by making use of a tilt sensor associated with the solenoid to derive a prediction of the ratio of the horizontal and vertical components of the field at a position vertically above or below the solenoid If that predicted value of the ratio is then compared with the measured value of the ratio, the two will coincide when the detector is vertically above the solenoid Thus, by moving the detector until such coincidence is obtained, the position of the solenoid can be determined

Fuel injector and method

Abstract: A direct injection fuel injector and method of operation wherein high fuel pressure exerting an opening force on an injection valve is slightly overbalanced by a return spring tending to close the valve. A first solenoid acts to open the valve against the excess return spring force and a second solenoid acts to close the valve when the first solenoid is de-energized. Rapid valve closing is provided by energizing the second solenoid before de-energizing the first solenoid, the force of the second solenoid when the valve is open being insufficient to overcome the force of the first solenoid holding the valve open. Thus, the second solenoid magnetic force is fully developed and quickly closes the injection valve when the first solenoid is de-energized. Various additional features are disclosed.

Electronic control of transmission line pressure

Abstract: A method and apparatus are provided for controlling the hydraulic line pressure in an automatic transmission for a vehicle in response to the measured pressure and torque transmitted through the transmission such that a minimum hydraulic line pressure is provided to the frictional elements to achieve a non-slip condition through the transmission which increases transmission efficiency and fuel economy. Hydraulic line pressure is controlled by activating a solenoid activated valve. Control signals are based on measured hydraulic line pressure, engine speed, turbine speed, vehicle speed, driver selected gear, and torque converter operating condition for the solenoid actuated valve. The present invention further provides a closed-loop adaptive control technology to learn the minimum line pressure to compensate for variability in the clutch return springs, friction characteristics, surface finishes, as well as hydraulic wear, and changes over the life of the transmission. Further, when one of the line pressure components fails, the method provides open loop control.

Rotary flow-path exchanging valve

Abstract: In a rotary flow-path exchanging valve, the magnetic force generated in a pair of main magnetic pole pieces (66) by energization of an electromagnetic solenoid is acted on a multi-pole magnet (71) of a main valve element accommodated within a valve housing (1) so that the main valve element (3) is rotated to exchange a flow-path. The multi-pole magnet (71) is made of a plastic magnet of plastic material mixed with magnetic powder. The main valve element (3) and multi-pole magnet (71) are integrally formed by multiple molding. A pair of main magnetic pole pieces (66) magnetically connected to one polarity of the electromagnetic solenoid (11) are arranged. A pair of auxiliary magnetic pole pieces (70) connected to the other polarity of the electromagnetic solenoid (11) are arranged at positions out of phase from the magnetic pole pieces by 90°. The pair of auxiliary magnetic poles (70) are opposed to portions of the multi-pole magnet (71) having a reverse polarity to that of portions of the multi-pole magnet (71) opposite to the main magnetic poles (66).

A superconducting probehead applicable for nuclear magnetic resonance microscopy at 7 T

Abstract: A practical cryogenic probehead for NMR microscopy is described. The superconducting coil is composed of a YBa2Cu3O7 layer on a LaAlO3 substrate. The probehead consists of a continuous flow cryostate with a room temperature bore for the sample. For better performance the sample can be positioned in the center of the coil. To evaluate the gain in sensitivity, spin-echo images are presented which compare the YBa2Cu3O7 (YBCO) resonator to a room temperature and a cryogenic Cu resonator. These results are corroborated through theoretical calculations. To estimate the potential of superconducting coils for NMR microscopy we have made a theoretical comparison of an YBCO resonator with a microscopic solenoid with three winding.

Method for controlling electromagnetic proportional pressure control valve

Abstract: In vibrating a spool of a spool-valve type electromagnetic proportional pressure control valve by applying a dither current so that no static friction acts on the spool, the dither effect tends to weaken in a region where the current is small and in a region where the current is so large as to cause magnetic saturation. An alternating dither current is superimposed on the current supplied to an electromagnet to vibrate the spool with an amplitude small enough not to affect the liquid pressure, and in a control region where the ratio of the solenoid force Fsol to the current I is small, the dither current is controlled so that its amplitude is larger or its frequency is lower than in other regions.

Suspension control apparatus utilizing a PWM type proportional solenoid valve

Abstract: In the suspension control apparatus of the present invention utilizing a PWM type proportional solenoid valve, in which a current in a form such that a dithering current is superimposed on a target current is applied to a solenoid, when the average intensity of the applied current falls outside a predetermined range, a ratio between a time period during which the PWM signal having a decrease duty ratio is applied and a time period during which the PWM signal having an increase duty ratio is applied is changed so that an amplitude of the dithering current can be maintained at a predetermined level. Therefore, an undesirable increase in hysteresis with respect to a damping force can be suppressed, to thereby ensure good reponsivity for controlling a damping force, regardless of the average intensity of the applied current.

Solenoid controlled bolt control for an electronic lock

Abstract: An electronic combination lock of the self-powered type, wherein the electrical energy for operation of the lock is developed within the lock itself, has a solenoid which magnetically seals in the activated position, thus preserving the "open" condition of the lock until such time as the operator may withdraw the bolt. Significantly, there is no requirement for continued electrical power to hold the solenoid and the latching mechanism in a condition for lock opening.

Dual solenoids on a single circuit and fuel injector using same

Abstract: An electronically controlled device, such as a fuel injector, includes a first solenoid and a second solenoid attached to the injector body An electrical circuit is attached to the injector body, and includes a positive terminal and a negative terminal connected to the first solenoid and the second solenoid The electrical circuit permits energization of one of the first solenoid and the second solenoid when electrical current flows in either direction between the first terminal and the second terminal However, the electrical circuit permits energization of the other of the first solenoid and the second solenoid only when current flows in a single direction between the first terminal and the second terminal

Edge-wound solenoids and strongly coupled ring resonators for NMR and MRI

Abstract: An edge-wound NMR solenoidal sample coil is made by winding at least two turns of flattened wire around a cylindrical coilform such that the major cross-sectional axis of the flat wire is perpendicular to the axis of the solenoid. The space between turns near the center is greater than the space between turns at the ends but less than the major cross-sectional dimension of the flat wire. The flattened wire is magnetically compensated by forming copper tubing around paramagnetic wires. The resulting solenoid has considerably higher η F Q and B 1 homogeneity than prior-art solenoids of comparable size and transverse transparency. Similar principles may be used to improve the segmented, transparent, loop-gap resonator for breast and other imaging applications by using segmented planar ring resonators, tightly coupled by means of balanced transmission lines at the magic angle, with outermost conductive surfaces oriented more in the radial than axial direction. Similar principles may also be used to produce an improved, segmented, conical surface coil.

Hydraulically driven, multiple rotor riding trowel

Abstract: High performance, multiple rotor riding trowels for finishing concrete comprise hydraulic circuitry enabling complete joystick control to the operator. The rigid trowel frame mounts separate spaced-apart, downwardly-projecting, bladed rotor assemblies that frictionally engage the concrete surface. The rotor assembly blades finish the surface while supporting the trowel. The rotor assemblies are tilted with double acting, hydraulic cylinders to effectuate steering and control. Double acting hydraulic cylinders also control blade pitch. Separate gimbaled, hydraulic motors revolve each rotor assembly. A joystick system enables operator hand control with minimal physical exertion. The joystick system activates electrical circuitry that fires solenoid control valves to energize various hydraulic cylinders that tilt the rotors and alter blade pitch. The hydraulic steering control circuit driven by a motor driven pump pressures a flow divider circuit to control the solenoid tilt control valves. A bypass-valve in line before the flow divider enables an operator to customize the trowel steering speed. A motor drive control circuit responsive to a hydraulic pump controls each hydraulic drive motor, and provides for speed control and heat dissipation.

Control system for toroidal type continuously variable transmission

Abstract: A toroidal type continuously variable transmission whose gear ratio is varied by changing the position of a trunnion is provided with double-slider valves driven by stepping motors and linear solenoid valves. The gear ratio control is performed by controlling position of the double-slider valves when the vehicle travels at speeds higher than a specified speed or by controlling directly line and relief pressures applied to the trunnion through the solenoid valves.

Image optical-to-tactile converter

Abstract: A system is provided including a tactile assembly having a plurality of solenoid units adapted to transfer to an extended orientation upon the actuation thereof. Also included is a camera unit for generating an image indicative of a present perspective of objects situated in a predetermined direction. Next provided is control circuitry for actuating the solenoid units to simulate the image generated by the camera unit such that the solenoid units actuated are those which correspond to pixels within the image that have either a higher or lower brightness.

Rapid computer-aided design method for fast-acting solenoid actuators

Abstract: The paper describes a general method for the preliminary design of fast-acting solenoid actuators. Moving armature, drive circuit and nonlinearities are modeled as well as eddy currents for solid iron devices. The electromagnetic model is obtained by computing two magnetisation characteristics corresponding to the extreme positions of the armature and a novel interpolation function for the intermediate positions. This function, characterising the magnetic configuration of the actuator, is computed analytically and leads also to an analytical formulation of the magnetic force. In order to achieve extremely fast computation, eddy currents are modeled through a new type of electric equivalent network, derived directly from Maxwell's equations and taking into account the actual BH nonlinearities, moving armature and device geometry. The method is demonstrated on a pot-core solenoid actuator and compares favourably with finite element results and measurements.

Solenoid-operated valve assembly

Abstract: A solenoid-operated valve assembly is configured in such a way that one of multiple receiving connectors 4A and 4B of different forms is attached to a first end block 2a via the corresponding one of holders 5A and 5B having the same mounting mechanism, thereby enabling either the receiving connector 4A or 4B to be selectively attached.

Sealed transfer valve assembly

Abstract: A sealing article 17 is provided in the opening edge of a depression 2c provided in a manifold 2 to connect a supply connector 16 and a receiving connector 44 in an air-tight manner. A solenoid section 33, in which a solenoid 31 in each of pilot valve 21a and 21b and a receiving connector 44 that supplies power to connector 31 are sealed into a synthetic resin 45, is provided in a transfer valve 3A. Solenoid section 33 has a lamp circuit board 49 mounted on its outer surface to receive power from receiving connector 44, and includes power supply indicator lamps 48; and a cover 50, covering the whole of lamp circuit board 49, mounted to form an air-tight seal on its outer surface via a gasket 52.

Solenoid self-cleaning pressure valve for automatic vehicle transmission

Abstract: A system for controlling an automatic vehicle transmission, including a gear system and hydraulic clutches which hold a member of the gear system stationary to produce gear reduction or reverse, having an oil line which connects the clutches to an oil pressure source, a pressure control valve having a solenoid provided in the oil line which generates a regulated oil pressure to be supplied to the clutches in response to a current supplied to the solenoid, a switch valve provided in the oil line which switches the oil pressure to be supplied to the one of the clutches between the regulated oil pressure and a line pressure. In the system, it is discriminated whether the pressure control valve does not supply the regulated oil pressure to the clutches and if so, a dither current is supplied to the solenoid such that the valve repeatedly performs a vibrational motion to remove any grit therefrom, thereby removing grit without causing gear-shift shock or clutch vibration.

Thermal trip unit with magnetic shield and circuit breaker incorporating same

Abstract: A solenoid type magnetic trip assembly for a molded case circuit breaker includes an armature biased against an adjustable stop by a tension spring to set the initial gap for the magnetic trip, so that the spring bias remains constant for the full range of the initial gap. The armature includes an elongated magnetically permeable member mounted by a frame to slide longitudinally along a pair of guide rails. The frame defines a trip surface axially aligned with the elongated magnetically permeable member which engages a trip arm on a trip bar to trip the circuit breaker in response to a predetermined level of overcurrent. A bimetal providing a thermal trip function is cantilevered from a support spaced from the trip bar by the armature, but has a terminal portion at the free end projecting toward the trip bar and through which the elongated magnetically permeable member of the armature extends. A radially enlarged slug on the free end of the elongated magnetically permeable member of the armature is subjected to a magnetic force opposite to the force generated by load current tending to pull the armature into the solenoid coil. This opposing force increases as the initial gap increases, placing the slug closer to the magnetic frame, so that a greater range of trip currents can be selected despite limited room for armature travel. A gap in the magnetic frame prevents short circuiting the magnetic field where the few turns of a large gauge coil wire produce an unsymmetrical winding. A magnetic shield protects the bimetal from deformation during high current short circuits.

PWM solenoid driver and method

Abstract: A solenoid driver circuit includes an input terminal for receiving a solenoid actuation pulse, an output terminal for connection to a terminal of a solenoid coil, a pull-in current adjustment terminal, and a hold-in current duty cycle adjustment terminal. A pull-in current duration circuit includes a first input coupled to the input terminal, an output producing a pull-in current duration pulse, and a second input coupled to the pull-in current adjustment terminal. A hold-in current duty cycle control circuit includes a first input coupled to receive a triangular waveform signal, a second input coupled to the hold-in current duty cycle adjustment terminal, and a third input coupled to the output of the pull-in current duration circuit. An output transistor includes a control electrode coupled to an output terminal of the hold-in current duty cycle control circuit, and a current carrying terminal coupled to the output terminal. The hold-in current duty cycle control circuit applies a drive pulse to the control electrode of the output transistor for the duration of the pull-in current duration pulse, followed by a sequence of PWM hold-in current pulses respectively turning the output transistor on and off until the end of the solenoid actuation pulse.