• The Transactions of the Korean Institute of Electrical Engineers P
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• v.56 no.2
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• pp.65-73
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• 2007

In this study, the pulse charger and voltage regulator are proposed that can reuse the waste lead acid battery. The first we develop the voltage regulator that can reuse the waste lead battery. And the pulse current is applied to the terminal of the waste lead acid battery. The voltage regulator is available principle of the pulse current which can reduce the sulfate to incipient material such as Pb and PbO2. Therefore the internal resistance of the lead acid battery is decreased, the performance of the lead acid battery is improved and the durability is prolonged. The second we develop the pulse charger using the voltage regulator. The pulse charger uses the switch mode of the forward convert method. The pulse charger maintain the constant voltage in state removing the lead acid battery and when it connected the pulse charger, it is converted the charge mode of the constant current immediately. It continues the rapid charge until the full state of the lead acid battery. After that the pulse charger is converted to the charge mode of constant voltage automatically, and then it continues the normal charge. The experiment results show that the effectiveness of the voltage regulator and pulse charger such as the good performance and the prolonged durability in lead acid battery of the small and large capacity.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.628-633
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• 1994

A new Riemannian geometric model for the controlled plant is proposed by imbedding the control vector space in the state space, so as to reduce the dimension of the model. This geometric model is derived by replacing the orthogonal straight coordinate axes on the state space of a linear system with the curvilinear coordinate axes. Therefore the integral manifold of the geometric model becomes homeomorphic to that of fictitious linear system. For the lower dimensional Riemannian geometric model, a nonlinear optimal regulator with a quadratic form performance index which contains the Riemannian metric tensor is designed. Since the integral manifold of the nonlinear regulator is determined to be homeomorphic to that of the linear regulator, it is expected that the basic properties of the linear regulator such as feedback structure, stability and robustness are to be reflected in those of the nonlinear regulator. To apply the above regulator theory to a real nonlinear plant, it is discussed how to distort the curvilinear coordinate axes on which a nonlinear plant behaves as a linear system. Consequently, a partial differential equation with respect to the homeomorphism is derived. Finally, the computational algorithm for the nonlinear optimal regulator is discussed and a numerical example is shown.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.443-446
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• 2012

A thrust control valve of a liquid rocket engine plays a role to increase or decrease the thrust of an LRE by modulating the flow rate of propellant into a gas-generator. This paper deals with a flow regulator that has functions of not only modulating thrust but also maintaining constant flow rate regardless of pressure change at inlet or outlet of the flow regulator. A direct acting flow regulator was fabricated and tested for the comparison of experimental and simulation results under steady-state conditions. The drawbacks and limitations of the flow regulator were analyzed. Also the new design of a flow regulator was proposed.

• Journal of IKEEE
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• v.23 no.2
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• pp.552-556
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• 2019

This paper present a capless low drop out regulator (LDO) that improves the load transient response characteristics by using a current regulator. A voltage regulator circuit is placed between the error amplifier and the pass transistor inside the LDO regulator to improve the current characteristics of the voltage line, The proposed fast transient LDO structure was designed by a 0.18 um process with cadence's virtuoso simulation. according to test results, the proposed circuit has a improved transient characteristics compare with conventional LDO. the simulation results show that the transient of rising increases from 1.954 us to 1.378 us and the transient of falling decreases from 19.48 us to 13.33 us compared with conventional capless LDO. this Result has improved response rate of about 29%, 28%.

• Journal of IKEEE
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• v.27 no.3
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• pp.258-264
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• 2023

This paper proposes an LDO regulator with a built-in ESD (Electro Static Discharge) protection circuit to effectively operate and prevent destruction of the LDO (Low Drop Out) regulator according to the load current. The proposed LDO regulator can more effectively adjust the gate node voltage of the pass transistor according to the output voltage of the LDO regulator by using an additional feedback current circuit structure. In addition, it is expected to have high reliability for the ESD situation by embedding a new structure that increases the holding voltage by about 2V by reducing the current gain on the SCR loop by adding a P+ bridge to the existing ESD protection device.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1726-1729
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• 1997

In general, the solvability of linear robust output regulation problem are not preserved under time-sampling. Thus, it is found that the digital regulator implemented by itme-sampling of anlog output regulator designed based on the continuous-time linear system model is nothing but a 1st order approximation with respect to time-sampling. By the way, one can design an improved sampled-data regulator with respect to sampling time by utilizing the intrinsic structure of the system. In this paper, we study the system structures which it is possible to design an improved sampled-data regulator with respect to sampling time.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.227-230
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• 2004

The regulator that was designed for space use must be operating on the severe circumstance. For example, operating temperature is below 90K and operating pressure is 20.7 MPa. The design of regulator for liquid propulsion system was accomplished and dynamic characteristic was analyzed successfully.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.2
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• pp.1-6
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• 2006

The pressure regulator which is used for controlling the reducing pressure in the piezoelectrically driven pneumatic valve has been studied. The pneumatic valve of this study object is 2-stage type and consists of a piezoelectric actuator, a controller, a poppet valve and a pressure regulator. Nominal flow of 50 lpm, maximum operating pressure of 0.9MPa and frequency characteristic of 10Hz and over are required in this pneumatic valve, but the pressure regulator is needed because piezoelectric actuator has no ability to control the pressure of 0.9MPa directly. In this study, bimorph type PZT actuator of $25.2mm(L){\times}7.2mm(W){\times}0.5mm(H)$ with constant of $-220{\times}10-12$ CN-1 was proposed and investigated. Maximum operating force of 0.052 N and maximum displacement of $63{\mu}m$ were gotten from the fabricated PZT actuator. From the analysis results, the orifice diameter of 0.6mm for a piezoelectric actuator was derived and then the pressure regulator which can be operated under 0.15 MPa easily was designed and manufactured. Performance and effects of design parameters were simulated by the Simulink of Matlab software, and it was confirmed that the performance characteristics of manufactured pressure regulator are superior in the common use pressure range of 0.5 MPa to 0.7 MPa. The results show that the proposed pressure regulator is suitable for the pneumatic valve with a PZT actuator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1677-1683
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• 2015

To cope with exhaust gas regulation, Diesel engine applied to electronic control system. As it accurately regulated the injected fuel mass and the fuel efficiency and the output are increased but the noise and the vibration are decreased. In order to keep the performance of Electronic Diesel Control System, it is important to accurately control the fuel pressure. However, when the regulator of fuel pressure is not controlled properly, the failure phenomenons(starting failure, staring delay, accelerated failure, engine mismatch et al.) occur because the fuel pressure is not stabilize. In this study, effects on a fuel pressure, engine rotating speed according to the control rate of fuel-pressure regulator are investigated in order to analyzed the performance variation with failure of fuel-pressure regulator. As a result, when the control rate of a fuel-pressure regulator is 4%~6% lower than that of standard condition, the variation of engine's rpm and return fuel flow is increased, and the abnormal condition was occurred. Besides, it is possible to diagnose the failures on fuel-pressure regulator under these conditions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.12 s.243
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• pp.1299-1306
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• 2005

The suitable pressure regulator modeling at each opening ratio and pressure ratio is very important to obtain reliable results, especially in small scale pipeline network analysis such as a pressure regulator system. And it is needed to confirm both whether temperature recovery is achieved after passing by the pressure regulator's narrow neck and how much amount of low temperature area that can cause condensate accumulation is distributed by various PCV models and driving conditions. In this research, the numerical model resembling P company pressure regulator that is used widely for high pressure range in commercial, is adopted as the base model of CFD analysis to investigate pressure regulator's flow characteristics at each pressure ratio and opening ratio. And it is also introduced to examine pressure regulator's critical flow characteristics and possibility of condensation or freezing at each pressure ratio and opening ratio. Additionally, the comparison between the results of CFD analysis and the results of analytic solution obtained by compressible fluid-dynamics theory is attempted to validate the results of CFD modeling in this study and to estimate the accuracy of theoretical approach at each pressure ratio and opening ratio too.