• The Journal of Korean Institute of Communications and Information Sciences
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• v.7 no.1
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• pp.10-17
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• 1982

Recently, there has been a great interest in the realization of analog fiters using switched and fixed capacitors and active elements. It is known that a switched capacitor has an performance much better that a resistor in the characteristics of temperature and linearity, and can be fabricated on the much smaller area than the resistor. In this paper all the resistors in the gyrator filter network are relpaced by the switched capacitors for an SC-Gyrator filter circuit can be fully integrated into a single chip by using MOS technology. By experiments we show that the response of designed SC-Gyrator filter is much similar to that of its protorype gyrator filter.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.8
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• pp.455-460
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• 1999

A novel zero-voltage-transition (ZVT) PWM converter for switched reluctance motor (SRM) drives is proposed. A simple auxiliary circuit which consists of one active switch, one resonant inductor, and three diodes provides ZVS condition to all main switches and diodes allowing high frequency operation of the converter with high efficiency. The auxiliary circuit is placed in parallel with the main power flow path and thus it handles only a small fraction of the main power. So, the power rating of the auxiliary circuit can be very small (about 30% of main power). So, the auxiliary circuit can be realized with small power rating and low cost. Operation, features and characteristics of the proposed converter are illustrated and verified on a 1.5 kW, 50 kHz IGBT based (a MOSFET for the auxiliary with) experimental circuit.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.626-630
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• 1999

A new integrated single-stage zero current switched(ZCS) quasi-resonant converter (QRC) for the power factor correction(PFC) converter is introduced in this paper. The power factor correction can be achieved by the discontinuous conduction mode(DCM) operation of an input current. The proposed converter has the characteristics of the good power factor, low line current harmonics, and tight output regulation. Furthermore, the ringing effect due to the output capacitance of the main switch can be eliminated by use of active clamp circuit.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.61-64
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• 2003

GPRS is designed for transmitting packet data and supposed to take its radio resource form the pool of channels unused by GSM voice services. In this paper, The GPRS and GSM circuit switched services share the same radio resource. Whenever a channel is not used by circuit switched services, it may be utilized by GPRS. In this paper, the main aim is performance and comparison resource management policies with channel de-allocation in GPRS network. Three resource management policies is voice priority, R-reservation, dynamic reservation.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.6
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• pp.916-926
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• 1994

A high frequency and soft-switched AC-to-DC rectifier employing a series-type resonant circuit is proposed to overcome the disadvantages of the conventional peak-rectifying circuit. Using the proposed rectifier, the high power factor and low harmonic currents are obtained in the AC line. Furthermore, several advantages such as the high power density and wide output voltage range can be available. Through the simulation and experimental results, the usefulness of the proposed rectifier is verified.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.207-210
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• 1996

This paper describes the analysis of the operation of the switched snubber in order to depress the surge voltage in the MOS-FET inverter. In this paper, the N-channel MOS-FET which operates faster than the P-channel MOS-FET was used for the inverter circuit. So, the inverter and switched snubber can operate at high-frequency in the order of MHz. The cause of generating the surge voltage in the high frequency inverter has been cleared, and then how to depress the surge voltage using the switched snubber consisting of an N-channel MOS-FET has been given. Furthermore, described is the power loss within the switched snubber which is made of an N-channel MOS-FET. The inverter having the N-channel MOS-FET used as a switched snubber can drive such a low impedance load such as mega-sonic transducer for a mega-sonic studied cleaner sufficiently.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.569-572
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• 2014

This paper presents a CMOS switched-capacitor interface circuit for MEMS capacitive sensors. It consist of a capacitance to voltage converter(CVC), a second-order ${\Sigma}{\Delta}$ modulator, and a comparator. A bias circuit is also designed to supply constant bias voltages and currents. This circuit employes the correlated-double-sampling(CDS) and chopper-stabilization(CHS) techniques to reduce low-frequency noise and offset. The designed CVC has a sensitivity of 20.53mV/fF and linearity errors less than 0.036%. The duty cycle of the designed ${\Sigma}{\Delta}$ modulator output increases about 5% as the input voltage amplitude increases by 100mV. The designed interface circuit shows linearity errors less than 0.13%, and the current consumption is 0.73mA. The proposed circuit is designed in a 0.35um CMOS process with a supply voltage of 3.3V. The size of the designed chip including PADs is $1117um{\times}983um$.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.570-573
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• 2001

This paper presents the characteristics of Switched Reluctance Motor (SRM) based on 3D Equivalent Magnetic Circuit Network Method (3D EMCNM). 3D EMCNM supplements magnetic equivalent circuit by numerical technique using distributive magnetic circuit parameters. However in case of SRM the previous 3D EMCNM which uses fan shape element is not proper for analysis. This paper solved this problem by developing the trapezoid element and verified the validity of the suggested element by comparing the results of 3D EMCNM with 2D FEM.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.5
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• pp.730-736
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• 1995

This paper presents the design of a CMOS programmable slew rate operational amplifier based upon a newly proposed concept, that is a switched parallel current subtraction circuit with adaptive biasing technique. By utilizing the newly designed circuit, it was proven that slew rate was linearly controlled and power dissipation was optimized. If the programmable slew rate amplifier is employed into mixed signal system, it can furnish the convenience of timing control and optimized power dissipation. Simulated data showed the slew rate ranging from 5. 83V/$\mu$s to 41.4V/$\mu$s, power dissipation ranging from 1.13mW to 4.1mW, and the other circuit performance parameters were proven to be comparable with those of a conventional operational amplifier.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.1
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• pp.7-15
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• 2002

The paper proposes the characteristics analysis for a Transverse flux type Switched Reluctance Motor(TSRM) considering the nonlinear magnetic phenomena. To investigate the nonlinear parameters of magnetic equivalent circuit, the designed TSRM is analyzed by the 2D and 3D finite element method as functions of input current and angular displacement. On the base of FEM analysis results, the current, torque, back EMF and output power wave of TSRM are simulated from the motion equation by MATLAB/Simulink. The simulated performance characteristics for a 4-phase, 24-pole TSRM are verified by experimental results of a prototype TSRM.