著者

寺口 直希 南 政孝

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.139, no.5, pp.259-263, 2019-05-01 (Released:2019-05-01)

参考文献数

25

---

A Tesla coil is a resonant transformer circuit that generates very high voltages which are made to arc through the air. Recently, a solid state Tesla coil was produced according to developing the semiconductor. In addition, the solid state Tesla coil makes sound by the air discharge. Hence, the sound is used as musical devices. In the past, the musical solid state Tesla coils are generated by PWM (Pulse Width Modulation) method. However, it is difficult to use the high pitch sound and the tone color. This paper investigates the musical solid state Tesla coil by using not PWM method but PRF (Pulse Repetition Frequency) method. As the result, the proposed musical solid state Tesla coil provides good sound.

著者

堤 泰行 草野 善照 小野 訓 藤井 寛一 檜垣 勝

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.111, no.11, pp.979-987, 1991-11-20 (Released:2008-07-15)

参考文献数

9

被引用文献数

4 4

---

Effect of discharge inception voltage on electromagnetic noise spectra in VHF and UHF region from spark discharge at hemisphere-plane electrodes in atmosphere is studied. The discharge inception voltages are changed by several means, such as increasing gap length from 2mm to 6mm, or UV-ray irradiation, or increasing stress concentration at the electrode tip, or spreading dust such as cotton cloths, acylic resin particles, copper particles, or alminum particles on the plane electrode.When the discharge inception voltage is increased, macroscopic slope of noise spectra from 100MHz to 1 GHz decreases generally, that is, high frequency components of noise increase with thevoltages.These phenomena can be explaned by theoretical analysis based onToepler's Law of spakdischarge and Hertz's dipole EM radiation law. As the exceptional cases, low dicharge inception voltages by metal particles or by positive stress concentration at the electrode tip do not contribute much to suppression of high frequency components of the noise.

著者

木部 道也 長嶋 満宏 土志田 実 釜 啓輔 大中道 崇浩

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.129, no.11, pp.746-750, 2009-11-01 (Released:2009-11-01)

参考文献数

7

被引用文献数

3 3

---

This paper describes an uncooled infrared (IR) camera especially optimized for small size & weight, less power consumption without degrading noise equivalent temperature difference (NETD). This camera has two features, including a wafer-level chip scale vacuum package with 160x120 SOI-diode array and germanium lid for good IR transmission, and also a real-time signal correction capability with respect to ambient temperature. These features enabled the considerable size/power consumption reduction and the operation without thermoelectric cooler (TEC) which usual IR cameras require for temperature stabilization. As a result, we realized compact infrared camera (less than 71grams) with low-power consumption and excellent NETD of 22 mK (F/0.8 optics).

著者

田村 哲志 瀬戸本 龍海 田口 常正

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.120, no.2, pp.244-249, 2000-02-01 (Released:2008-07-15)

参考文献数

13

被引用文献数

3 7

---

We describe for the first time the basic illumination characteristics of lighting source using 10cd-class InGaN-based LEDs (an efficacy of 151m/W) under a driving condition of AC 100V at 60Hz. Several hundred white LEDs with series connections were arrayed on a glass epoxy substrate and were driven by adjusting a current of less than 20mA under the AC 100V. The dependence of temperature and injection current on both the emission spectra and intensity were measured. The white LED array indicates distinct two electroluminescence peaks at 460 and 555nm at room temperature, which are related to the recombination emissions from the InGaN MQW blue LED and from the YAG: Ce phosphor, respectively. We have obtained a maximum luminous intensity of about 10000lx at a distance of 30cm from the LED array, which is sufficient for the practical application. After operating for 1 hr, a temperature of the LED array increased up to about 65°C without a cooling system.

著者

園田 潤 八巻 宏太

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.130, no.1, pp.74-80, 2010-01-01 (Released:2010-01-01)

参考文献数

29

---

We develop an automatic Live Linux rebuilding system for science and engineering education, such as information processing education, numerical analysis and so on. Our system is enable to easily and automatically rebuild a customized Live Linux from a ISO image of Ubuntu, which is one of the Linux distribution. Also, it is easily possible to install/uninstall packages and to enable/disable init daemons. When we rebuild a Live Linux CD using our system, we show number of the operations is 8, and the rebuilding time is about 33 minutes on CD version and about 50 minutes on DVD version. Moreover, we have applied the rebuilded Live Linux CD in a class of information processing education in our college. As the results of a questionnaires survey from our 43 students who used the Live Linux CD, we obtain that the our Live Linux is useful for about 80 percents of students. From these results, we conclude that our system is able to easily and automatically rebuild a useful Live Linux in short time.

著者

山田 忠比古 後田 澄夫 近藤 芳孝

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.114, no.6, pp.459-466, 1994

被引用文献数

1

---

Luminosity of wire corona has been observed by the technique of the computed tomography. The light output from wirecorona has been compared with the calculated result. Spatial distributions of space-charge and current density of each type ofcharges carrier in a corona field has been also determined by computing the ionization and attachment process under the Deutschassumption and compared with experimental results.<br>The calculated results along the symmetry axis of the electrodes show very good agreement with measurements.Unfortunately, there is a slight difference between the experimental results and those of the calculation under the Deutschassumption in the distribution of luminosity.

著者

鶴田 浩一 江原 玄

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.111, no.10, pp.939-940, 1991

著者

赤崎 勇

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.124, no.2, pp.107-113, 2004 (Released:2004-05-01)

参考文献数

37

---

Breakthroughs in crystal growth and conductivity control of nitride semiconductors during last two decades have led to such developments as high-brightness blue, green and white light-emitting diodes and long-lived violet laser diode and so forth. The high electron saturation velocity in GaN is also suitable for application in high-speed/high power electronic devices. All of these nitride-based devices are the most environmentally-friendly ones available. They are tough and should enable a tremendous saving in energy. Further progress in the area of crystal growth and device engineering is necessary for the development of new frontier devices based on nitride semiconductors.

著者

脇坂 俊幸 松嶋 徹 古賀 久雄 奥村 浩幸 桑原 伸夫 福本 幸弘

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.140, no.12, pp.557-564, 2020-12-01 (Released:2020-12-01)

参考文献数

30

---

In this paper, the influence to electromagnetic environment was evaluated on the outside of buildings where power line communication (PLC) systems were installed to a three-wire three-phase power distribution line. The electric field strength was measured at 140 points in five factories, in two office buildings, and in one stadium. Since many radio waves existed in the environment, the electric field strength when PLC system was operated and was not operated was measured. The influence was evaluated by the cumulated occurrence probability because the frequency characteristics of the electric filed strength changed by the measurement points. The results showed that the occurrence probability was not changed when the PLC system was operated and was not operated. The electric field strength was calculated by the common mode current obtained from the test result, and this indicated that the occurrence probability was lower than the measured occurrence probability of electric field strength.

著者

鈴木 譽久 浅野 賢二 間宮 昇 渡部 浩志 堀 吉宏 内原 可治

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.118, no.6, pp.701-705, 1998

被引用文献数

1

---

We have investigated a clock generated from a wobbled groove for higher density magneto-optical disk. Neither the readout signal nor the recording signal needs to include a clock element, because a clock derived from the wobbled groove is used for recording and readout. Therefore this clock does not depend on the quality of the readout signal. For this reason, a clock generated from the wobbled groove is effective for higher density recording.

著者

三木 恵 和田 淳

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.114, no.10, pp.727-728, 1994-09-20 (Released:2008-07-15)

参考文献数

3

著者

野坂 隆 増田 陽一郎

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.126, no.8, pp.821-829, 2006 (Released:2006-11-01)

参考文献数

20

被引用文献数

3 3

---

To investigate the mechanism of the polarization fatigue of ferroelectric thin films, we analyzed the relationship between the crystalline defects of electrode/ferroelectric interface and fatigue characteristics of PZT thin films. Pt/PZT/Pt thin films were prepared by the chemical solution deposition method, and conditions of Pt/PZT interface were analyzed by TEM-EDX analysis, thermally stimulated current methods and I-V Properties. The PZT layers of about 30nm near the top Pt electrodes became an n-type due to the oxygen vacancies and they formed the contact similar to the top electrode of Pt/n-type PZT/p-type PZT. Because the height and width of the Schottky barrier in the Pt/PZT interface had reduced with the increase of the fatigue, this band structure was observed in the electric field where the Fowler-Nordheim currents were lower than usual. This is considered to be caused by the increase of crystalline defects near the interface due to the impressing of the bipolar pulse. This phenomenon was observed quantitatively by TSC analysis, and the TSC peak of 490K became larger with the increase of the fatigue. The activation energy of the TSC peak was 0.8ev and the defect density was 2.5×1019/cm3, which is consider to be produced by Pb defects.

著者

土江 基夫 宮本 晃男

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.113, no.1, pp.39-42, 1993-01-20 (Released:2008-07-15)

参考文献数

9

被引用文献数

1

---

Solubility of copper in insulating oil depends on sulfur contents and component of insulating oil. As increasing of sulfur contents, the solubility of copper becomes large. When being added di-tert-butylparacrezole and benzotriazole into the insulating oil, solubility of copper becomes small. Evolution of combustible gas is proportional to amount of copper in insulating oil, and type of gas pattern due to results of gas analysis in insulating oil depends on chemical component of insulating oil. In the case of low aromatic content oil, hydrocarbon gas evolves preferentially, but in the case of high aromatic content oil, hydrogen gas evolves preferentially. Although degradation of the insulating oil is effected by solution of copper, breakdown voltage of insulating paper is not falling down.

著者

熊澤 孝夫 中川 渡 鶴丸 秀一

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.125, no.10, pp.828-834, 2005

被引用文献数

6 9

---

Bow-tie tree(BTT) generated from contaminant, <i>e.g.</i>, metal, carbon, amber(over cured resin) or void is a deterioration factor of XLPE cable. In particular, BTT in contact with inner or outer semi-conductive shield could significantly lower residual AC breakdown voltage of HV power cable. To evaluate influence of water and ion diffusion on generation and progress of BTT, we investigated relationship between water content of XLPE and the generation of BTT by various accelerated aging. The number of BTT in XLPE samples with accelerated aging under open condition, involving evaporation of water in which samples were immersed, was very large compared with closed condition. Furthermore, when samples were intermittently immersed in water, the number of BTT in samples was large compared with samples immersed continuously. In these experiments the generation of BTT seemed to have nothing to do with changes in water content before and after accelerated aging. Therefore, it was suggested that diffusion of ions rather than water in XLPE played an important role in the generation of BTT.

著者

中川 晶司 佐保 賢志 馬杉 正男

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.140, no.3, pp.169-170, 2020-03-01 (Released:2020-03-01)

参考文献数

7

---

An analysis between the atmospheric state change and lightning discharges in the autumn (from Sep to Nov. 2011 and 2016) seasons in Japan is presented in this paper. In evaluating the number of lightning activities, we calculated SSI which is used to predict thunderstorms. We confirmed that the modified SSI for the winter season can be effective for evaluating the lighting activities in the autumn season, meaning that the lighting discharges in this season tend to be affected by the low-level atmospheric state condition.

著者

熊田 亜紀子 尾崎 浩一 清水 康広 日高 邦彦

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.121, no.7, pp.712-713, 2001-07-01 (Released:2008-07-15)

参考文献数

5

被引用文献数

1 1

著者

八代 健一郎

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.116, no.7, pp.579-585, 1996-06-20 (Released:2008-07-15)

参考文献数

42

著者

劉 源興 浦井 一 石井 彰三

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.113, no.1, pp.17-24, 1993-01-20 (Released:2008-07-15)

参考文献数

8

---

X-ray radiation: bremsstrahlung and characteristic X-ray, in electron beam bombarded X-ray source is numerically analyzed with the Monte Carlo technique. In order to calculate the radiation, scattering processes such as bremsstrahlung, plasmon scattering, elastic collision, inner shell ionization, and secondary electron emmission are taken into account.The calculated relation between X-ray intensity and electron energy agrees with the experimental results reported by other groups. The intensity of bremsstrahlung has strong dependence on the angle because of absorption. The thickness of a foil target in which the X-ray intensity is maximized is smaller than electron mean range. Back scattered X-ray intensity in conventional X-ray tubes varies as the target angle. The peak of X-ray intensity angular dependence is obtained when the angle is 20°-40°.

著者

酒井 英男 小林 剛 泉 吉紀 中山 武 服部 克巳

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.136, no.5, pp.291-296, 2016

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Study of the electric self-potential (SP) and the magnetic field was conducted at the explosion seismic experiment in Ooyama, Toyama Prefecture. The explosion was induced by 450 kg gun powder placed at a depth of 32.2-75 m. The SP was measured by four electrodes arranged in a line crossing the explosion point, where the distance of each electrode from the explosion ranged from 10 to 100 m. Induced SP changes consisted of two portions, namely, fluctuations with shorter periods (∼10 ms) and fluctuations with longer periods (∼50 ms). Regarding the latter, the amplitude was in proportion to the span length of electrode couples and the fluctuations arrived faster at the electrode couples nearer to the explosion. Further, the increment of ground level in SP was observed in each electrode couple after the explosion, which was concordant with the distribution of apparent resistivity underground studied by the survey. The magnetic field measured by the fluxgate magnetometer at the site 35 m north from the explosion also showed change of a few nT after the explosion. This may have been caused by change of magnetic properties underground.

著者

笹田 一郎

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.121, no.12, pp.1062-1065, 2001-12-01 (Released:2008-07-15)

参考文献数

15