• Journal of IKEEE
• /
• v.4 no.2 s.7
• /
• pp.202-211
• /
• 2000

Utilizing the circuit simulator SPICE, we designed a 1.9GHz CMOS up-conversion mixer and explained in detail the simulation procedures including device modeling for the circuit design. Since the measured characteristics of the chip fabricated using the $0.5{\mu}m$ standard CMOS process had shown a big deviation from the characteristics expected by the original simulations, we tried to figure out the proper reasons for the discrepancies. Simulations considering the discovered problems in the original simulations have shown the validity of the simulation method tried for the design. We have shown that the utilized standard CMOS process can be used for the implementation of the chip characteristics similar to those of the equivalent chip fabricated using the GaAs MESFET process.

• Transactions of The Korea Fluid Power Systems Society
• /
• v.4 no.4
• /
• pp.21-27
• /
• 2007

A hydraulic breaker for construction machinery generally used for the destroying and disassembling of buildings, crashing road pavement, breaking rocks at quarry and so on. So the measurement of the impact energy of a hydraulic breaker is very important thing to prove its capability to manufacturers and customers. Therefore the prediction of impact energy in design process is very helpful to the most of breaker manufacturers. In this study, we carried on modeling and simulation of a hydraulic breaker to predict impact energy via commercial CAE software. The modeling and simulation of a hydraulic breaker was achieved with two parts. One is a hydraulic circuit analysis part via AMESim and the other is impact strain analysis part via ANSYS.

• Proceedings of the KIEE Conference
• /
• 1993.07b
• /
• pp.781-783
• /
• 1993

The GTO model is based on the Ebers-Moll equation extened to include the three-junction devices and a detailed description of the implementation of the model equation as well as defferent tests are discussed. Problems to be considered for the snubber design, such as voltage spike reduction, maximum GTO anode current, and switching power, were discussed using the calculation model. The macro model is very useful for simulation of GTO circuit and high power circuit switch in high frequency and complex structure.

• Proceedings of the KSR Conference
• /
• 1999.05a
• /
• pp.328-335
• /
• 1999

Three phase full bridge rectifier has been used to obtain dc voltage from three phase ac voltage source. The rectifier system has drawbacks that power factor is low and power flow is unidirectional. Therefore, when dc voltage increases due to regeneration of power the dynamic resister for dissipation of regeneration power must be installed. But three phase PWM converter can be controlled to operate with unity power factor and bidirectional power flow. Therefore when the PWM converter is used as do supply system, the dissipating resistor is not necessary. On this thesis, in order to design a controller having good performance, the hee phase PWM converter is completely modeled by using circuit DQ-transformation and thus a general and simple instructive equivalent circuit is obtained; the inductor set becomes a second order gyrator-coupled system and three phase inverter becomes a transformer as well. Under given phase angle(${\alpha}$) and modulation index(MI) of the three phase inverter, the dc and ac characteristics are obtained by analysis of the transformed equivalent circuit The validity of the equivalent circuit is confirmed through PSPICE simulation. And based on the dc and ac characteristics a controller with unity power factor is proposed.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.137-137
• /
• 2000

In this research. we developed Tire Roller Prototype which is operated hydraulic transmission system. For develop the theoretically computer aided system, we practiced the simulation of hydraulic system and dynamic modeling and will compare with the experiment results of Tire Roller Prototype. We conceptualize the new hydraulic system and derive the equations of motion for dynamic analysis. Finally, we will design the controller, which can manage the hydraulic circuit of servo mechanism system. We define new hydraulic system and integrate modeling of Tire Roller through simulation of h\ulcornerdraulic system and design of controller. From above procedure. Hydraulic transmission system characteristics and target performance can be investigated. To follow the required performance, we select the parts of Tire Roller. We manufactured the prototype of Tire Roller, and will install the equipment for experiment.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.8 s.173
• /
• pp.42-49
• /
• 2005

Our purpose is to develop a precision magnetic displacement sensor that has sub-micron resolution and small size probe. To achieve this, we first have tried to establish mathematical models of a magnetic sensor in this paper. The inductance model that presents basic measuring principle of a magnetic sensor is based on equivalent magnetic circuit method. Especially we have concentrated on modeling of magnetic flux leakage and magnetic flux fringing. The induced model is verified by experimental results. The model, including the magnetic flux leakage and flux fringing effects, is in good agreement with the experimental data. Subsequently, based on the augmented model, we will design magnetic sensor probe in order to obtain high performances and to scale down the probe.

• ETRI Journal
• /
• v.32 no.4
• /
• pp.530-539
• /
• 2010

As the conventional silicon metal-oxide-semiconductor field-effect transistor (MOSFET) approaches its scaling limits, quantum mechanical effects are expected to become more and more important. Accurate quantum transport simulators are required to explore the essential device physics as a design aid. However, because of the complexity of the analysis, it has been necessary to simulate the quantum mechanical model with high speed and accuracy. In this paper, the modeling of double gate MOSFET based on an adaptive neuro-fuzzy inference system (ANFIS) is presented. The ANFIS model reduces the computational time while keeping the accuracy of physics-based models, like non-equilibrium Green's function formalism. Finally, we import the ANFIS model into the circuit simulator software as a subcircuit. The results show that the compact model based on ANFIS is an efficient tool for the simulation of nanoscale circuits.

• Proceedings of the KIEE Conference
• /
• 2001.04a
• /
• pp.324-328
• /
• 2001

This paper presents parallel operation and control loop design of ZVT(Zero Voltage Transition) Full Bridge DC/DC Converter. At parallel operation of ZVT Full Bridge Converter, dynamic current shared inductor devides the same current of unit converter and ZVT circuit and aids to high efficiency in the system. Base on the modeling of ZVT. Full Bridge Converter, the control loop is designed using a simple two-pole, one-zero compensation circuit. To show the validity of the design procedures, the small signal analysis of the closed loop system and open loop system is carried out and the superiority of the dynamic characteristics is verified through the experiment with a 2kW, 50kHz prototype converter.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1002-1004
• /
• 2005

This paper describes the performance analysis and design of single-phase self-excited induction generators. In this study, it is proposed to design the proper capacitance for self-excitation and voltage regulation, also. This methods are based on the induced MMF equations between main and the auxiliary winding. For the least influence between the two capacitors, the self-excited capacitor is selected under no load condition, while the series capacitor is designed under loaded condition. For the steady state analysis, the equivalent circuit of single-phase induction generators is used as circuit modeling using the double-revolving field theory. The validity of proposal methods and designed generator system will be confirmed by experimental and computed results.

• Proceedings of the KIPE Conference
• /
• 2017.07a
• /
• pp.231-232
• /
• 2017

This paper describes the design and implementation of a 2.5kW (500V, 5A) simmer circuit that maintains the ionization of xenon gas inside the lamp. The design is based on a LCC resonant converter in continuous conduction mode (CCM) with above resonant frequency to take advantage of high power density from using parasitic elements such as the leakage inductance in a power transformer. In addition, since the converter has current source output characteristics, it is suitable for maintaining ionization of the lamp having the negative resistance load characteristic. To verify this converter design, PSpice modeling was performed. Finally, the developed simmer circuit is verified by a resistive load of rated performance and the Ionization maintenance operation of the xenon flash lamp.