• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.157-160
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• 2002

In this paper, a novel lumped equivalent circuit for a conventional parallel directional coupler is proposed. The equivalent circuit and design formula for the presented lumped element coupler is derived based on the even-and odd-mode properties of a parallel-coupled line. By using the derived design formula, we have designed the 3㏈ and 10㏈ lumped element directional couplers at the center frequency of 100Mhz. Furthermore, a chip type directional coupler has been designed to fabricate with multilayer configurations by employing the Low Temperature CofiredCeramic (LTCC) process. Designed chip-type directional coupler has a 10㏈-coupling value at the center frequency of 2㎓. Excellent agreements between simulations and measurements on the designed directional couplers show the validity of this paper

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1947-1948
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• 2008

This paper presents the implementation of Power Line Communication(PLC) module which can reduce standby-power consumption. The suggested PLC module consists of PLC modem, coupling circuit, ZCP(Zero-Cross Point) Circuit and main SMPS control relay. The test results under power line communication test-bed used home appliance show the 77% saving of standby-power.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.299-303
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• 2005

A lighting control switch, extended to incorporate a power line communication technology, is developed. The system uses not an exclusive microprocessor but a general one, and developed PPM protocol. The coupling circuit is a type of an isolation LC filter, and the impedance of the circuit was designed as low as possible to extend signal transmission distance. The frequency of the carrier, considering the data length and signal attenuation as the length of power lines, was set at 250 kHz. Tests on a prototype in an indoor power lines have shown that the switch has a stable operation with the distance of power lines

• Journal of information and communication convergence engineering
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• v.14 no.4
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• pp.268-271
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• 2016

An efficient inductive switching noise suppression technique for mixed-signal integrated circuits (ICs) using standard CMOS digital technology is proposed. The proposed design technique uses a parallel RC circuit, which provides a damping path for the switching noise. The proposed design technique is used for designing a mixed-signal circuit composed of a ring oscillator, a digital output buffer, and an analog noise sensor node for $0.13-{\mu}m$ CMOS digital IC technology. Simulation results show a 47% reduction in the on-chip inductive switching noise coupling from the noisy digital to the analog blocks in the same substrate without an additional propagation delay. The increased power consumption due to the damping resistor is only 67% of that of the conventional source damping technique. This design can be widely used for any kind of analog and high frequency digital mixed-signal circuits in CMOS technology

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.9
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• pp.355-363
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• 1984

An ideal and an approximate eauivalent circuits of a face-mounted PZT piezoelectric transformer were introduced from the equivalent circuit taking into account the mechanical loss of a PZT piezoelectric disk vibrator. And several expressions for the resonant frequencies and for the voltage ratios were derived from the approximate circuit of the transformer. From the experiments on the vltage ratios regarding the frequency variation without load and on the load variation at resonant frequency, it was found that the voltage ratio increased with the increase of load resistance and decreased sharply with the slight deviation from the resonant frequency, and that no-load voltage ratio at the resonant frequency was proportional to the product of the mechanical quality factor and the square of the electromechanical coupling factor of the vibrator.

• Journal of Power Electronics
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• v.2 no.1
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• pp.32-45
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• 2002

This paper proposes an unified definition of powers for various circuit conditions such as balanced/unbalanced, sinusoidal/non-sinusoidal, and linear/nonlinear, fur single-phase systems and three-phase systems. Conventional reactive power is more classified into an interactive power and an alternating power. These powers are defined both in the time domain and the frequency domain consistently, and agree well with the conservation law. Several important power quality factors are defined to measure and evaluate the power quality fur the various circuits in the single-phase and three-phase systems. Simulation results show the power quality factors can evaluate and classify the various circuit conditions clearly.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.164-166
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• 1999

In this study, dynamic analysis of Linear DC motor has been performed. Dynamic characteristic is carried out from coupling the electrical circuit equation and mechanical kinetic equation. Trust constant and circuit parameters are obtained by FE analysis and static characteristic experiment. From the previous results, dynamic analysis is performed and the appropriateness of analysed result is verified by comparing with experimental result.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.145-147
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• 1999

A voice type Moving Coil Linear Oscillatory Actuator(MC-LOA) has unbalanced magnetic circuit structure. Its asymmetric magnetic flux distribution along the mover directions causes shifting of displacement center to one side. Therefore, this paper analyzes both thrust and displacement characteristics and settles the unbalanced flux problem by performing shape optimization. The propriety of the improved design model has been verified by dynamic analysis based on the coupling of kinetic and electric equations.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1165-1167
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• 2000

This paper describes a current fed high frequency resonant inverter used as the power supply for sealing-wax. The proposed inverter can reduce switching losses, noise and voltage stress at turn-on and turn-off. The analysis of proposed circuit uses normalized parameter and characteristic estimation which is needed in each step before design is generally described according to normalized frequency ($\mu$), coefficient of coupling($\kappa$) and all parameters. The theoretical analysis is proved through experiment and this circuit shows that it can be used practically as the power supply system for sealing wax and DC-DC converter.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.347-349
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• 2007

Charge equalization scheme for HEV lithium-ion battery system is proposed in this paper, where all the primary windings with in parallel bi-directional switches are coupled in series to provide the equalizing energy from the whole battery string to the specific under charged cells. Moreover, to realize minimized size of equalization circuit employing the proposed cell balancing scheme, the optimal power rating design rule according to equalization time and SOC distribution of imbalance is proposed. A prototype of HEV lithium-ion battery system of four cells shows the outstanding charge equalization performance while maintaining greatly reduced size of cell balancing circuit.