• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1239-1243
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• 2004

A novel voltage-current reference circuit for stable voltage-current applications is Proposed. Circuits for a positive and for a negative voltage-current reference are presented and are designed with commercial CMOS technology. The voltage-current reference that is stable over ambient temperature variations is an important component of most data acquisition systems. These results are verified by the HSPICE simulation $0.8{\mu}m$ parameter. As the result, the temperature dependency of output voltage and output current each is $0.57mV/^{\circ}C$, $0.11{\mu}A/^{\circ}C$ and the power dissipation is 1.8 mV on 5V supply voltage.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.5
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• pp.545-551
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• 2022

We proposed a design method for constant current pyro squib circuit. The current method using N MOSFET for the stability problem has a weakness of the current change, requiring a new design. This paper identified the problem with conventional squib circuit where the current is reduced by 25 % when maximum resistance is 3 ohms. Thus, we proposed a stable constant current driving circuit using P MOSFET and PNP BJT. We confirmed stable constant circuit operation through simulations and measurements of the proposed circuit design where the current did not change until the resistance reached 3 ohms.

• Progress in Superconductivity and Cryogenics
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• v.1 no.2
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• pp.37-42
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• 1999

The stability of high-temperature superconducting current leads for cryogenic devices are investigated. By assuming full transition from superconducting state to normal state at a transition temperature, the HTS current at a transition temperature, the HTS current lead shows bifurcation phenomenon. There is a bifurcation shape-factor, HTS leads have three steady state. Below the bifurcation shape-factor, the superconducting current lead is unconditionally stable, because there exists only one steady-factor HTS current lead is conditionally stable depending on the shape and intensity of disturbance.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.215-218
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• 2009

In this paper, temperature stable current and voltage references using simple CMOS bias circuit are proposed. To obtain temperature stable characteristics of bias circuit a bandgap reference concept is used in a conventional circuit. The parasitic bipolar transistors or MOS transistors having different threshold voltage are required in a bandgap reference. Thereby the chip area increase or the extra CMOS process is required compared to a standard CMOS process. The proposed reference circuit can be integrated on a single chip by a standard CMOS process without the extra CMOS process. From the simulation results, the reference current variation is less than ${\pm}$0.44% over a temperature range from - $20^{\circ}C$ to $80^{\circ}C$. And the voltage variation is from - 0.02% to 0.1%.

• Journal of Radiation Protection and Research
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• v.43 no.4
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• pp.131-136
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• 2018

Background: We investigated the current characteristics of a thin-film Ag electrode on a chemical vapor deposition (CVD) diamond. The CVD diamond is widely recognized as a radiation detection material because of its high tolerance against high radiation, stable response to various dose rates, and good sensitivity. Additionally, thin-film Ag has been widely used as an electrode with high electrical conductivity. Materials and Methods: Considering these properties, the thin-film Ag electrode was deposited onto CVD diamonds with varied deposition thicknesses (${\fallingdotseq}50/98/152/257nm$); subsequently, the surface thickness, surface roughness, leakage current, and photo-current were characterized. Results and Discussion: The leakage current was found to be very low, and the photo-current output signal was observed as stable for a deposited film thickness of 98 nm; at this thickness, a uniform and constant surface roughness of the deposited thin-film Ag electrode were obtained. Conclusion: We found that a CVD diamond radiation detector with a thin-film Ag electrode deposition thickness close to 100 nm exhibited minimal leakage current and yielded a highly stable output signal.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.69-71
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• 2003

Switched reluctance machine has much attention because of high efficiency, high power and DC series torque characteristics with a traction drive. But the motor has to have a regenerative mode when it is adopted in an electric vehicle. A current divergence during the regeneration makes difficulties in the control of SRM. This paper proposes a reference current limitation strategy for a stable regeneration based on simulations and experimental tests. The motor is operated with conventional current limit and switching angle control method in motoring mode. Simulations and experiments are executed to verify proposed method.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1565-1577
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• 2016

For grid-connected LCL-filtered inverters, dual-loop current control with an inner-loop active damping (AD) based on capacitor current feedback is generally used for the sake of current quality. However, existing studies on capacitor current feedback AD with a control delay do not reveal the mathematical relation among the dual-loop stability, capacitor current feedback factor, delay time and LCL parameters. The robustness was not investigated through mathematical derivations. Thus, this paper aims to provide a systematic study of dual-loop current control in a digitally-controlled inverter. At first, the stable region of the inner-loop AD is derived. Then, the dual-loop stability and robustness are analyzed by mathematical derivations when the inner-loop AD is stable and unstable. Robust design principles for the inner-loop AD feedback factor and the outer-loop current controller are derived. Most importantly, ensuring the stability of the inner-loop AD is critical for achieving high robustness against a large grid impedance. Then, several improved approaches are proposed and synthesized. The limitations and benefits of all of the approaches are identified to help engineers apply capacitor current feedback AD in practice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1368-1373
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• 2008

An electrochemical reactor was designed and operated to treat the solution containing endocrine disruptive compounds such as phenol and bisphenol A. An experiment involving the electrochemical oxidation of bisphenol A was performed with the use of a dimensionally stable anode (DSA). The apparent current, conductivity, and the gap between cathode and anode were selected as design parameters. The phenol removal rate increased with an increase in apparent current. The bisphenol A removal rate increased with an increase in apparent current efficiency. An increase in the conductivity also led to an increase in the rate of removal of bisphenol A. The gap between cathode and anode did not affect the bisphenol A removal rate or the cathodic current efficiency.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.128-133
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• 2011

In this study, the steel material for shipbuilding(LR-A class) was used, and FCAW was taken advantage of 3G attitude and they are welded by different welding ways. As a result of analyzing wave with welding monitoring system, the stable values are obtained which are the first floor(electronic current 164~182 A, voltage 24 V), the second floor(electronic current 174~190 A, voltage 22~25 V), the third floor(electronic current 158~188 A, voltage 22~25 V), and fourth floor(electronic current 172~184 A, voltage 22~25 V), at this time, the stable wave standard deviation and changing coefficient could be obtained. When the welding testing through nondestructive inspection was analyzed know defect of welding, there was no defect of welding in A, D, E, but some porosities in B, and slag conclusion near the surface in C, because the length of arc was not accurate, and the electronic current and voltage was not stable. After observing the change of heat affect zone through micro testing, each organization of floor formed as Grain Refinement, so welding part was fine, the distance of heat affect zone is getting wider up to change the values of the electronic current and voltage. As a result of degree of hardness testing, the hardness orders were the heat affect zone(HAZ), Welding Zone(WZ), and Base Metal(BM). When the distribution of degree of hardness is observed. B is the highest degree of hardness The reason why heat effect zone is higher than welding zone and base metal, welding zone is boiled over melting point($1539^{\circ}C$) and it starts to melt after the result of analysis through metal microscope, so we can know that delicate tissue is created at the welding zone. Therefore, in order to get the optimal conditions of the welding, the proper current of the welding and voltage is needed. Furthermore the precise work of welding is required.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.20-23
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• 2002

A Switched Reluctance Generator attracts much attention because of high efficiency, simple cont-reliability, with traction drive. But the theories that have been adopted as SRG control methods up to the present are complicated. This paper proposes reference current limitation strategy for stable generation of SRM. The proposed method is verified by simulation and experiments.