• Journal of Power Electronics
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• v.7 no.4
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• pp.278-285
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• 2007

Recently, plasma display panels (PDP) have become the most promising candidate in the market for large screen size flat panel displays. PDPs have many merits such as a fast display response time and wide viewing angle. However, there are still concerns about high cost because they require complex driving circuits composed of high power switching devices to generate various voltage waveforms for three operational modes of reset, scan, and sustain. Conventional PDP driving circuits use path switches for voltage separation and a scan switch to offer a scan voltage for reset and scan operations, respectively. In addition, there exist reset switches to initialize PDPs by regulating the wall charge conditions with ramp shaped pulses, which means the necessity of specific power devices for the reset operation. Because power for the plasma discharge accompanied by a large current is transferred to a panel via path switches, high power rating switches are used for path switches. Therefore, this paper proposes a novel low-cost PDP driving scheme achieved by not only eliminating path switches but also merging the function of reset switches into other switches used for sustain or scan operations. The simulated voltage waveforms of the proposed topology and experimental results implemented in a 42-inch panel to demonstrate the validity of using a new gate driver that merges the functions of power switches are presented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.745-748
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• 2003

This paper presents a study on pull cord switch system which is employed in various industry for emergency stop of the equipments. By using power line communication(PLC) technique, in this paper, a new method for operation position detection of pull cord switch is suggested without complicated wiring of separate cables which utilize only 2 lines. Also, using control function of PLC IC, a reset signal for each switch reset can be implemented in the switch status control/sensing device. Finally, this paper shows validity and practical applicability of the proposed operating position sensing system of pull cord switch by implementing the system and revealing the response time and signal through the PLC line.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.965_966
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• 2009

In this paper, a new soft-switching Two-switch Forward converter topology has been proposed. Compared with conventional two-switch forward converter, the proposed converter employs an auxiliary switch and a clamp capacitor to instead of two reset diodes, not only its duty cycle can exceed 0.5 to achieve wide range input voltage, but also soft switching can be achieved for all switches. Especially, voltage stress across main switches can be clamped at $1/2V_{in}$, voltage stress across auxiliary switch can be clamped at $V_{in}$. In addition, due to clamp capacitor series with the transformer, duty ratio can be extended with equation $V_o=\frac{V_{in}(1-D}D{N}$. Therefore, as a kind of better cost-effective approach, it is very attractive for high input, wide range and high efficiency application.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.6
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• pp.464-470
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• 2022

A new type of soft-switching forward converter is proposed in this study. By adding only a few components, the inductor, diode, switch, and capacitor exhibit higher efficiency than the conventional forward converter. Therefore, the switching losses of the proposed forward converter are considerably reduced compared with those of the conventional forward converter. In addition, the reset winding is not used because of the capacitor employed in the auxiliary circuit. The auxiliary capacitor is adopted for zero-current-transition operation and for dissipating magnetization energy. The performance of the proposed forward converter is validated using experimental results from a 60 W, single-output, forward converter prototype, and design guidelines are presented.

• Progress in Superconductivity
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• v.5 no.1
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• pp.13-16
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• 2003

In this work, we have studied about an RSFQ (Rapid Single Flux Quantum) switch element. The circuit was designed, simulated, and laid out for mask fabrication. The switch cell was composed of a D flip-flop, a splitter, a confluence buffer, and a switch core. The switch core determined if the input data could pass to the output. “On” and o“off” controls in the switch core could be possible by utilizing an RS flip-flop. When a control pulse was input to the “on” port, the RS flip-flop was in the set state and passed the input pulses to the output port. When a pulse was input to the “off” port, the RS flip-flop was in the reset state and prevented the input pulses from transferring to the output port. We simulated and optimized the switch element circuit by using Xic, WRspice, and Julia. The minimum circuit margins in simulations were more than $\pm$20%. We also performed the mask layout of the circuit by using Xic and Lmeter.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.505-507
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• 2008

A conventional active-clamp forward (ACF) converter is a favorable candidate in low-to-medium power applications. However, the switches suffer from high voltage stress, i.e., sum of the input voltage and the reset capacitor voltage. Therefore, it is not suitable for high input voltage applications such as a front-end converter of which the input voltage is about 400-$V_{dc}$. To solve this problem, three-switch ACF (TS-ACF) converter, which employs two main switches and one auxiliary switch with low voltage stress, is proposed. Utilizing low-voltage rated switches, the proposed converter is promising for high input voltage applications with high efficiency and low cost.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.637-641
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• 1989

We have developed 3-stage of Magnetic Switch System based on the nonlinearities of ferromagnetic material used in the saturable inductor, and made experiment of parameter optimization and output stabilization of Magnetic Switch System. The cross-section and conductor burns of each satarable inductor were optimized 30 $cm^2$ 19.25 $cm^2$ 5, and 25 $cm^2$ 2, respectively. With this condition, 6.2 us [FWHM], 96 A pulse at first stage was compressed into 0.4 us[FWHM], 1.61 kA pulse at last stage. The current gain and compression ratio were 16.8, 17, respectively. ln addition, System output was stabilized with reset current of 6 A, 200 us.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.348-350
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• 1996

A new reset winding clamped forward converter with transformer voltage feedback technique for power factor correction with a single-switch/single-stage is proposed. The proposed converter gives the good power factor correction, low current harmonic distortions, and tight output voltage regulation. The prototype shows the IEC555-2 requirements are met satisfactorily with nearly unity power factor.

• Journal of Power Electronics
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• v.18 no.2
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• pp.356-363
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• 2018

The combination of a buck converter and a forward converter can be considered to accomplish a high step-down non-isolated converter. To decrease the insufficient step-down ratio of a regular buck converter and to distribute switch voltage stress, a forward-integrated buck (FIB) converter is proposed in this paper. The proposed interleaved DC-DC converter provides an additional step-down gain with the help of a forward converter. In addition to its simple structure, the transformer flux reset problem is solved and an additional magnetic core reset winding is not required. The operational principle and an analysis of the proposed FIB converter are presented and verified by experimental results obtained with a 240 W, 150 V/24 V prototype.

• English Language & Literature Teaching
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• no.5
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• pp.219-247
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• 1999

The purpose of this paper is to examine how Korean learners of English reset the "prodrop" parameter of Korean into "non-prodrop" parameter of English in the process of English acquisition. An experiment was conducted to 45 Korean learners of English on the prodrop phenomenon, namely on the null referential or null nonreferential subject, and subject-verb agreement by way of grammatical judgment. The results of the experiment are as follows: First, L2 learners follow the parameter of L1, and then reset the parameter of L2 regardless of the parameter of L1 as their L2 abilities advance. Thus, this study provides further support for the hypothesis that universal grammar is available via L1. Second, the referential subject is, at first, easier to acquire than nonreferential subject, and the triggering fact for the switch from [+prodrop] to [-prodrop] was the use of nonreferential subjects. Third, 3rd person agreement has no connection with the acquisition of the prodrop parameter as a result of subject-verb agreement. Therefore, these results indicate that verb agreement is not a trigger for the recognition of the obligatory subject.