• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5997-6003
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• 2011

To increase the driving distance of a natural gas vehicle, the high pressure of fuel charge is necessary and the development of the device reducing the pressure to suitable pressure for fuel of high pressure. In this study, Pressure characteristics at the pressure regulator, which is very important for gas supply systems for vehicles, are investigated. Numerical simulations are carried out to quantify pressures at regulators for several flow rates and to investigate pressure drop, hysteresis losses at some parts in the pressure regulator. Moreover, this paper presents a new kind of hydraulic simulation which is composed of CNG regulator. Lastly, experiments are carried out to verify the effectiveness of the prosed mathematical simulation with various regulator components as in real working condition.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.4
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• pp.47-58
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• 2002

The pressure regulator has been developed as a pressure-control device of propellant tank in KSR-III. The pressurization system of KSR-III is a basic pressurization system composed of pressurant, He tank and propellant tank. The pressure-control regulator is the most important part of gas-pressurized feed system along with He tank, pyrovalve and He fill valve. The first model of the regulator is tested to satisfy in leakage, strength and basic performance. The second model is tested in the overall test of the KSR-III propulsion system using water. From the test result of the second model, we conclude that the capacity of valve(Cv) must be increased in real system. The third model is modified and tested in the overall test of KSR-III propulsion system using propellant. Finally, the pressure-control regulator is qualified from firing test.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3335-3343
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• 2021

The impact of gamma radiation on a commercial off the shelf microcontroller board has been investigated. Three different tests have been performed to ascertain the radiation tolerance of the device from a nuclear decommissioning deployment perspective. The first test analyses the effect of radiation on the output voltage of the on-board voltage regulator during irradiation. The second test evaluated the effect of gamma radiation on the voltage characteristics of analogue and digital inputs and outputs. The final test analyses the functionality of the microcontroller when using an external, shielded voltage regulator instead of the on-board voltage regulator. The results suggest that a series of latch-ups occurs in the microcontroller during irradiation, causing increased current drain which can damage the voltage regulator if it does not have short-circuit protection. The analogue to digital conversion functionality appears to be more sensitive to gamma radiation than digital and analogue output functionality. Using an external, shielded voltage regulator can prove beneficial when used for certain applications. The collected data suggests that detaching the voltage regulator can extend the lifespan of the platform up to approximately 350 Gy.

• Journal of IKEEE
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• v.25 no.1
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• pp.201-205
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• 2021

In this paper present Low Drop-Out (LDO) regulator that improved load transient characteristics due to the push-pull detection structure. The response characteristic of the voltage delta value is improved due to the proposed push-pull sensing circuit structure between the input terminal of the LDO regulator pass transistor and the output terminal of the internal error amplifier. Voltage value has improved load transient characteristics than conventional LDO regulator. Compared to the conventional LDO regulator, it has an improved response speed of approximately 244 ns at rising time and approximately 90 ns at falling time. The proposed circuit was simulated by the samsung 0.13um process using Cadence's Specter and Virtuoso simulator.

• Journal of IKEEE
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• v.27 no.3
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• pp.308-312
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• 2023

The gate current sensing structure was proposed to more effectively control the regulation of the output voltage when the LDO regulator occurs in an overshoot or undershoot situation. In a typical existing LDO regulator, the regulation voltage changes when the load current changes. However, the operation speed of the pass transistor can be further improved by supplying/discharging the gate terminal current in the pass transistor using a gate current sensing structure. The input voltage of the LDO regulator using the gate current sensing structure is 3.3 V to 4.5 V, the output voltage is 3 V, and the load current has a maximum value of 250 mA. As a result of the simulation, a voltage change value of about 12 mV was confirmed when the load current changed up to 250 mA.

• Journal of IKEEE
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• v.26 no.1
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• pp.124-128
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• 2022

Conventional LDO regulator external capacitors can reduce transient response characteristics such as overshoot and undershoot. However, the capacitorless LDO regulator proposed in this study applied body technology to the pass transistor to improve the transient response and provide excellent current drive capability. The operating conditions of the proposed LDO regulator are set to an input voltage that varies from 3.3V to 4.5V, a maximum load current of 200mA, and an output voltage of 3V. As a result of the measurement, it was found that when the load current was 100 mA, the voltage was 95 mV in the undershoot state and 105 mV in the overshoot state.

• Journal of the Korean Institute of Gas
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• v.27 no.1
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• pp.57-62
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• 2023

The Gas Regulator EVENT is a signal sent by the Remote Terminal Unit(RTU) installed in each local gas regulator (hereinafter referred to as "regulator"), and is an abnormal alarm that can be intuitively checked in our client server. This is an important data that enables immediate dispatch order and initial action in the situation room when a regolator abnormality occurs, and can analyze the cause of the regulator abnormality. Looking at the trend of EVENT data for regulator over the past three years, there is a clear trend of increasing unchecked EVENT data. The increase in non-checking event (actual abnormality or noise event) may mean that firstly, mechanical or pressure abnormality occurs in the actual regulator, and secondly, there is no abnormality in the actual regulator, but communication error occurred in the RTU, reset. EVENT Data may be formed as if an abnormality occurred in the static voltage due to an error, sensor error, power failure (instantaneous power failure), etc. Among them, this study analyzed the recently generated unchecked EVENT data to identify critical noise events among RTU errors, which are noise events, and reviewed ways to increase the reliability of Regulator EVENTs by reducing them.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1673-1681
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• 2015

A low dropout (LDO) regulator with a wide-bandwidth is proposed in this paper. The regulator features a Human Body Model (HBM) 8kV-class high robustness ElectroStatic Discharge (ESD) protection circuit, and two error amplifiers (one with low gain and wide bandwidth, and the other with high gain and narrow bandwidth). The dual error amplifiers are located within the feedback loop of the LDO regulator, and they selectively amplify the signal according to its ripples. The proposed LDO regulator is more efficient in its regulation process because of its selective amplification according to frequency and bandwidth. Furthermore, the proposed regulator has the same gain as a conventional LDO at 62 dB with a 130 kHz-wide bandwidth, which is approximately 3.5 times that of a conventional LDO. The proposed device presents a fast response with improved load and line regulation characteristics. In addition, to prevent an increase in the area of the circuit, a body-driven fabrication technique was used for the error amplifier and the pass transistor. The proposed LDO regulator has an input voltage range of 2.5 V to 4.5 V, and it provides a load current of 100 mA in an output voltage range of 1.2 V to 4.1 V. In addition, to prevent damage in the Integrated Circuit (IC) as a result of static electricity, the reliability of IC was improved by embedding a self-produced 8 kV-class (Chip level) ESD protection circuit of a P-substrate-Triggered Silicon Controlled Rectifier (PTSCR) type with high robustness characteristics.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.11
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• pp.34-40
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• 2011

This paper presents a low-dropout (LDO) linear regulator using ultra-low output impedance buffer for frequency compensation. The proposed buffer achieves ultra low output impedance with dual shunt feedback loops, which makes it possible to improve load and line regulations as well as frequency compensation for low voltage applications. A reference control scheme for programmable output voltage of the LDO linear regulator is presented. The designed LDO linear regulator works under the input voltage of 2.5~4.5V and provides up to 300mA load current for an output voltage range of 0.6~3.3V.

• Journal of Drive and Control
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• v.17 no.1
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• pp.51-60
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• 2020

This study addresses the modeling of a bi-directional outlet variable swash plate type axial piston pump with two EPPR valves and an analysis of the response characteristics to the angle control of that pump. In this paper, the combination of the EPPR valve and double rod type piston is referred to as the EPPR regulator. The EPPR regulator is compact and inexpensive, and has good responsiveness. Under actual pump operating conditions, because of the various external conditions of the pump, inertia is applied to the swash plate, generating the tilting torque. Also, the tilting torque can delay or shorten the response characteristics of the regulator. So we validated them through the analysis using SimulationX and these results allow users to freely integrate the EPPR regulator into the desired system.