• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.3
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• pp.91-95
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• 2004

The pulsed power system is widely available for use in pulse generator applications. Generally, the pulse generator is required for very short pulse width and high peak value. We have designed and fabricated our own pulsed type power system and through its use, we investigated microbe removal characteristics. This paper introduces a simple pulsed power system for removing various microbes caused by dirty water. This system includes a 2 times power supply circuit, IR2110 operated by using a fixed voltage regulator 7812 and 7805, and the switching MOSFET (Metal Oxide Semiconductor Field Effect Transistor). We can also control this process by using a PIC one chip microprocessor. As a result, we can obtain good removing characteristics of various microbes by adjusting the charging voltage, the pulse repetition rate and the electrical field inducing time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05a
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• pp.180-183
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• 2002

The pulsed power system was widely making use good of many industrial and environments. The pulse generator generally required for short pulse duration and high peak value was forced to consider its volume and economy. In this paper, this system is designed and fabricated which has a compact size of pulse generator with switched MOSFET. We have studied the removal of rust material using Arc discharging. It have tested their characteristics by adjusting variable voltage charging and pulse repetition rate. As a result, We can eliminate rust materials with this device.

• Current Optics and Photonics
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• v.6 no.4
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• pp.407-412
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• 2022

We report on a diode-laser-pumped mode-locked Yb:KGW laser system, which delivers ultrashort pulses down to 89 fs at a repetition rate of 63 MHz, with an average power of up to 5.6 W. A fiber-coupled diode laser at 981 nm, operated with a compact driver, is used to optically pump the gain crystal via an off-axis parabolic mirror. A semiconductor saturable-absorber mirror is used to initiate the pulsed operation. Laser characteristics such as the pulse duration, spectrum bandwidth, and output power are investigated by varying the intracavity dispersions via changing the number of bounces between negative-dispersive mirrors within the cavity. Short pulses with a duration of 89 fs, a center wavelength of 1,027 nm, and 3.6 W of output power are produced at a group-velocity dispersion (GVD) of -3,300 fs². As the negative GVD increases, the pulse duration lengthens but the output power at the single-pulse condition can be enhanced, reaching 5.6 W at a GVD of -6,600 fs². Because of pulse broadening at high negative GVDs, the highest peak intensity is achievable at a moderate GVD with our system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1996.11a
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• pp.104-108
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• 1996

This paper deals with the design considerations and characteristics analysis of a SCR rectifier in pulsed over load operation. The Pulse repetition rate is one every 150 seconds and each current pulse width is 10 seconds. Therefore the characteristics of the transformer and SCR rectifier which consist the pulsed DC power supply are different from those of the conventional AC/DC power converters having continuous load. The variations of the DC output voltage drop, PF and THD versus the %Z of the transformer is analyzed through simulations and the experimental results thought to be useful in design high power pulsed DC power suppler.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.988-989
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• 2008

This paper describes a rapid pulsed power charging system for pulsed power application. It is capable of charging 35kJ/s energy up to 0.47uF 25kV within 3ms and maximum pulse repetition rate of 300 pps can be achieved. The charger is designed based on three-phase series resonant inverter followed by air cooled set-up transformers thus it has many advantages of lower weight, small size and high efficiency compared with large bulky traditional pulse charger system. Detail design procedure of resonant inverter and high voltage transformers is explained. Experimental results carried out at different condition and its results shows 90% efficiency at full load condition.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.279-282
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• 1990

This paper describes an nstrument for the detection and geometric location of partial discharge(PD) sources in transformers. This instrument measures electric current pulses and ultrasonic pulses simultaneously, counts the number of electrical pulse and determines the geometric location of PD in transformers. It was found that there is a relationship between partial discharge magnitude and pulse repetition rate when the applied test voltage and oil temperature were varied. Through the laboratory test using model transformer, it was clarified that this detector could be used, satisfactory for detecting and locating of PD in the transformer.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1416-1417
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• 2007

The high frequency pulsed power system is widely available for use in high frequency generator applications. We designed and fabricated our own high frequency pulsed power system to obtain very sort pulse width and high peak value and investigated microbe removal characteristics using it. This paper introduces a simple high voltage high frequency pulsed power system for removing various bacteria caused by dirty water. This system include power supply circuit, switching MOSFET, and flyback converter. We can also control the switching using a PIC one chip microprocessor. As a result, we can obtain good removing characteristics of various bacteria by adjusting the charging voltage, the pulse repetition rate and the electrical field inducing time.

• Korean Journal of Optics and Photonics
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• v.1 no.2
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• pp.169-177
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• 1990

We have constructed the laser system which was consisted of a high voltage pulse poner supply, a rapid high voltage spark gap and the Blumlein transmission line circuit of the multiple parallel plate capacitor type, and have studied the self-preionization effect from this laser system without additional modifications. The value of inductive or resistive loading of the laser oscillator seems to have a significant effect on the preionization. The optimal operational condition of this laser system was obtained at the inductive loading of L = I mtl across the laser tube with the spark gap distance of 6.0 mm. nitrogen pressure of 50 torr, when repetition rate was 70 Hz. Stability was found to be better than 2.0Yo and EIP was 867 V/cm.torr.

• Current Optics and Photonics
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• v.5 no.2
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• pp.180-185
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• 2021

A femtosecond-laser inscribed Yb:YAG surface channel waveguide (WG) laser with single-walled carbon nanotubes deposited on the top surface of the WG was passively Q-switched by evanescent field interaction. Q-switched operation of the 14-mm-long compact Yb:YAG WG laser was achieved near 1031 nm with two different pumping schemes (single- and double-pass pumping) with an output coupling transmission of 91%. The Q-switched pulse characteristics depending on the absorbed pump power were investigated for both pumping geometries and analyzed in detail based on theoretical modeling. The best performances (energy/pulse duration) for each configuration were 204.4 nJ/75 ns at a repetition rate of 1.87 MHz, and 201.1 nJ/81 ns at 1.75 MHz for single- and double-pass pumping, respectively.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1874-1875
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• 2004

A high rate deposition sputtering process of magnesium oxide thin film in oxide mode has been developed using a 20 kW unipolar pulsed power supply. The powersupply was operated at a maximum constant voltage of 500 V and a constant current of 40 A. The pulse repetition rate and the duty were changed in the ranges of 10 ${\sim}$ 50 kHz and 10 ${\sim}$ 60 %, respectively. The deposition rate increased with increasing incident power to the target. Maximum incident power to the magnesium target was obtained by the control of frequency, duty and current. The deposition rate of a moving state was 9 nm m/min at the average power of 1.5 kW. This technique is proposed to apply high through-put sputtering system for plasma display panel.