• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.197-203
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• 2014

The safety and arming device(SAD), one of the components of the fuzes, shall provide safety that is consistent with handling, storage, transportation, use, and disposal. In this paper, we describes the design of the SAD which includes the solenoid assembly and the solenoid driving circuit to improve the safety of the fuzes. The solenoid assembly consists of a coil assembly, a restoring spring, and a core. The solenoid assembly is added in the SAD as an additional safety device. In case of the normal circumstances, the core of the solenoid assembly restrains the $1^{st}$ and $2^{nd}$ safety devices of the SAD for those devices not to operate at all, so that the SAD can secure safety for storage, transportation, and use. In contrast, when the battery power is provided to the solenoid driving circuit just before the flight, the core confirms the power level and starts removing the restraint from the $1^{st}$ and $2^{nd}$ safety devices of the SAD, and then the SAD is able to change its mode from safety mode to armed mode. After firing, once the SAD's operations complete, the turned-on arming switch stops providing the power to the solenoid assembly automatically. It can reduce the power consumption at solenoid assembly. Therefore, the proposed solenoid driving circuit for the solenoid assembly not only unlocks the restrained solenoid assembly from the safety devices, but also saves the power consumption during the flight.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.122-128
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• 2012

Many of the liquid rocket engines use a hypergolic igniter with rupture disc ends located in the combustion chamber ignition line. In this study, the flow coefficient tests of the igniter, which have a solenoid valve upstream, were performed. The tension-type rupture discs for radial and circumferential scores and the igniter with them were tested using water at room temperature. The effects of the score, flow rate, the disc thickness, gas pocket and the solenoid valve on the coefficient were analyzed.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.9-15
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• 2017

Natural gas fuel has known to be very promising in terms of abundancy and economic value. Therefore it is widely treated as research topics in a variety field of production, storage and utilization. Natural gas has become one of the major sources for the power generation by using internal combustion engines(ICE). Development of natural gas fuel injection device should be preceded to realize a reliable natural gas fuel supply system for a MW class power generation reciprocating ICE. In this research, an injection valve which consists of solenoid and body part with a moving plate was designed and its dynamic performance was experimented in the engine-like environment. Displacement length and diameter of an armature and diameter of a solenoid coil were tested at former study. In this research the effect of materials of solenoid core, size of main housing inlet and supply gas pressure are examined.

• Journal of the Korean Society for Railway
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• v.19 no.3
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• pp.324-330
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• 2016

A magnetic contactor is a switching device widely used for electric circuits. For the operation of magnetic contactors, magnetic coils are essential; these coils create and interrupt the electric circuit. In this paper, the finite element analysis model was developed to reflect the experimental data, and was verified through alteration of the applied voltages and the numbers of turns. Effects of electromagnetic force on the geometrical variations of the facing poles for fixed and moving cores of two magnet coils were investigated. In addition, effects of slope and air gap size between two facing poles on the electromagnetic force were explored through the distribution of the magnetic flux density in the magnetic coils of a push-type solenoid. Through this analysis, the characteristics of the electromagnetic force against the facing poles were explored.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.3
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• pp.482-487
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• 2009

This research proposed a dashpot type mount design using MR fluids, and derived governing equation of the proposed design considering the design parameters of the mount and the Bingham characteristics of MR fluids, which affect the damping forces of the dashpot MR fluid mount. In odor to observe the change of magnetic properties which occurs from the solenoid, the effective length of the magnetic pole and the structure of core are selected as design parameters. The magnetic field quality is calculated in compliance with an equivalent magnetic circuit method. When the effective length of pole increases, the magnetic resistance of the pole of the MR mount decreased, and the magnetic flux density is increased. The result which uses a commercial business software and the result in compliance with equivalent magnetic circuit method shows the tendency which is similar.

• Journal of Sensor Science and Technology
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• v.12 no.2
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• pp.72-78
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• 2003

To observe the effect of excitation coil pitch on the micro fluxgate magnetic sensor, two sensors are fabricated using multi layer board process and the pitch distance of excitation coil are $260\;{\mu}m$ and $520\;{\mu}m$, respectively. The fluxgate sensor consists of five PCB stack layers including one layer of magnetic core and four layers of excitation and pick-up coils. The center layer as magnetic core is made of a Co-based amorphous magnetic ribbon with extremely high DC permeability of ${\sim}100,000$ and has a rectangular-ring shape to minimize the magnetic flux leakage. Four outer layers as excitation and pick-up coils have a planar solenoid structure and are made of copper foil. In case of the fluxgate sensor having the excitation coil pitch of $260\;{\mu}m$, excellent linear response over the range of $-100\;{\mu}T$ to $+100\;{\mu}T$ is obtained with sensitivity of 780 V/T at excitation sine wave of $3V_{p_p}$ and 360 kHz. The chip size of the fabricated sensing element is $7.3\;{\times}\;5.7\;mm^2$. The very low power consumption of ${\sim}8\;mW$ is measured. This magnetic sensor is very useful for various applications such as: portable navigation systems, telematics, VR game and so on.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.10
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• pp.48-57
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• 2008

MR Fluid, one of functional fluids, is developed for the application to automobile products. MR CDC damper using MR fluid has following principles. When ar electric current is applied to the solenoid, apparent viscosity of MR fluid passing through the annular gap which acts as magnetic circuits varies directly as the intensity of the current. These devices have a simple structure and excellent lime response characteristics, emerging as the alternatives of the conventional semi-active suspension systems. In this study, a design procedure of the magnetic circuit through the solenoid fore and the flux ring functioning as a magnetic path is investigated so as to optimize the design and performance of MR CDC dampers for the vehicles. In addition, an operating point on the B-H curve, the magnetization according to the variation in the annular gap, the pole piece width and the density of MR fluid are studied to design the optimal piston head within the restrained dimension range.

• Journal of the Korean Magnetics Society
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• v.17 no.3
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• pp.141-146
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• 2007

A new class of LC-resonator for micro magnetic sensor device was invented and fabricated by means of MEMS technique. The micro LC-resonator consists of a solenoidal micro-inductor with a bundle of soft magnetic microwire cores and a capacitor connected in parallel to the micro-inductor. The core magnetic material is a tiny glass coated $Co_{83.2}B_{3.3}Si_{5.9}Mn_{7.6}$ microwire fabricated by a glasscoated melt spinning technique. The core materials were annealed at various temperatures $150^{\circ}C,\;200^{\circ}C\;,250^{\circ}C\;,$ and $300^{\circ}C$ for 1 hour in a vacuum to improve soft magnetic properties. The solenoidal micro-inductors fabricated by MEMS technique were $500{\sim}1,000{\mu}m$ in length with $10{\sim}20$ turns. The changes of inductance as a function of external magnetic field in micro-inductors with properly annealed microwire cores were varied as much as 370%. Since the permeability of ultra soft magnetic microwire is changing rapidly as a function of external magnetic field. The inductance ratio as well as magnetoimpedance ratio (MIR) in a LC-resonator was varied drastically as a function of external magnetic field. The MIR curves can be tuned very precisely to obtain maximum sensitivity. A prototype magnetic sensor device consisting of the developed microinductors with a multivibrator circuit was test successfully.