Improved mercury arc lamps

The devitrification problem of capillary high pressure mercury lamps is shown to be caused by impurities in the natural quartz. It is shown that this problem may be solved by using synthetic quartz of low OH-content. An improvement of lamp life by an order of magnitude appears to be possible.     

Anode and cathode arc root movement during contact opening at highcurrent

This paper presents experimental research into the behavior of short circuit break arcs ignited between opening contacts. The investigation is applied to arc chamber geometries commonly used in miniature circuit breakers (MCB). The movement of the anode and cathode roots are individually plotted from optical data, allowing the relative motion to be compared. The effect of a range of MCB configurations on the arc root motion has been investigated. The experiment was configured so that the fixed contact was always the cathode. The results show that the two are roots do not move away from the contact region simultaneously. Often the cathode root moved off the fixed contact and away from the contact region before the anode root commutated from the moving contact. The delay in anode root commutation leads to a delayed cathode root movement. These events are explained in terms of arc root emission processes     

Construction and operating characteristics of a large-volume mercury arc plasma tube

The purpose of this communication is to describe the construction and operating characteristics of a mercury arc discharge tube which allows the generation of a large volume of stable, high-intensity plasma for use in experimental work with plasma-clad antennas operating at a frequency of a few GHz.     

铝合金微弧阳极氧化膜性能研究

研究的是在铝酸盐电解液体中对LF21、LY12铝合金进行微弧阳极氧化的技术.介绍了自制的微弧阳极氧化试验装置、实验基本操作工艺流程以及工艺流程详细说明.研究了铝酸钠电解液体系所生成的微弧阳极氧化膜的性能,其中包括微弧阳极氧化膜的膜层与基体金属的结合力、膜层的硬度以及膜层的耐腐蚀性能.     

Characterisation of TiN films prepared by electron shower,arc ion-plating and sputtering methods

It has been found that TiN films with high wear resistance and high adhesion can be prepared by electron shower deposition and arc ion plating on glass and austenitic stainless steel (SUS 316) substrates. The high wear resistance is principally explained by the grain size and surface morphology. Fine {100}-faceted crystals (10–150 nm) grew on the surface. The typical morphology of the crystals was triangular pyramidal. The crystallite size was changed by the bias voltage. Faceted crystals produced by arc ion plating were rounded and smoothed by a change in bias, but were unaltered in samples prepared by the electron shower process. The fine faceted surfaces had higher wear resistance than the granularly rounded ones. When TiO₂ was formed at the interface of the glass substrate, the adhesion was lowered. The high-adhesion film prepared by electron shower deposition contained a small amount of TiO₂ at the interface.     

Diode oscillation in high-voltage klystrons

Diode oscillations at frequencies between 1350 and 3700 Mc sometimes occurred in a particular high-voltage pulsed klystron. These frequencies agree closely with those calculated for an inverted spherical diode. The oscillations are often delayed a few microseconds after the electron beam is turned on. Experimental techniques revealed that two of the modes, TE41and TE61, with Q's of about 1000 had their highest electric fields in a region of the electron gun remote from the beam.     

Emitter current-crowding in high-voltage transistors

The problem of emitter current-crowding is treated for the case where the base is heavily doped with respect to the collector and the transistor is operating in the quasisaturation region. Closed-form solutions for terminal currents and current gain are derived in terms of elliptic integrals and other related functions. Good agreement with experimental data is demonstrated and various design implications of the theory are discussed.     

Second breakdown in high-voltage switching transistors

A 2-dimensional mathematical model which includes the avalanche multiplication and internal self-heating effects has been used to predict the internal behaviour of a typical high-voltage power-transistor design. Collector n?-n+ interface is the region of high electrical and thermal stresses which cause second-breakdown failure at high-current and high-voltage operating conditions.     

Avalanche breakdown in high-voltage D-MOS devices

A new type of voltage breakdown occurring in high-voltage D-MOS transistors is described. This effect severely reduces the high-voltage capability of these devices when the gate field plate is extended through the drift region toward overlapping the n⁺drain contact region. The breakdown is shown to be due to an avalanche phenomenon appearing close to the n⁺region, due to the very high field induced in this NIOS structure in nonequilibrium. A first-order theory is developed to confirm the conclusions of the experimental study.     

钽电容器的阳极选择器件结构的新进展正改善着许多应用中的ESR

开关式电源,微处理器和数字电路应用的一个共同趋势是降低高频工作时的噪声。为了做到这一点,元器件必须具备低ESR(电阻率)、高电容和高可靠性。     

Improved high-voltage lateral RESURF MOSFETs in 4H-SiC

High-voltage lateral RESURF metal oxide semiconductor field effect transistors (MOSFETs) in 4H-SiC have been experimentally demonstrated, that block 900 V with a specific on-resistance of 0.5 Ω-cm² . The RESURF dose in 4H-SiC to maximize the avalanche breakdown voltage is almost an order of magnitude higher than that of silicon; however this high RESURF dose leads to oxide breakdown and reliability concerns in thin (100-200 nm) gate oxide devices due to high electric field (>3-4 MV/cm) in the oxide. Lighter RESURF doses and/or thicker gate oxides are required in SiC lateral MOSFETs to achieve highest breakdown voltage capability     

Transient processes in high-voltage silicon carbide bipolar-junction transistors

The specific features of transient processes in high-voltage silicon carbide bipolar-junction transistors are studied theoretically and experimentally. It is shown that, in good agreement with the experimental results, the switch-off from the active mode can be described in a wide temperature range by the simple analytical expression derived in the study. The process in which a transistor is switched on to pass into the active mode is well described by a simple exponential dependence. The time constant of the switch-on process is determined by the average value of the collector capacitance before and after switch-on. A numerical model is suggested, based on a simple and physically transparent equivalent circuit describing, in good agreement with the experiment, both the transient processes of switch-on and switch-off in a SiC bipolar junction transistor, in both the active and saturation modes.     

Microplasma breakdown in high-voltage p?n junctions

The voltage-breakdown characteristics of controlled-avalanche junctions demonstrate the presence of microplasmas whose bistable current-switching properties are described. Microplasmas are exhibited by both diffused and alloyed junctions. The relationship between the breakdown voltage of the first microplasma with temperature for 1500?1800 V junctions is similar to that reported for 7?128 V junctions.     

Topics in recent studies with high-voltage electron microscopes

In this article, topics in recent studies with high-voltage electron microscopes (HVEMs) are reviewed. High-voltage electron microscopy possesses a number of advantages that cannot be afforded by conventional electron microscopy, thus providing a unique microscopy technique in both materials science and biological science. One of these advantages is the capability of continuously observing phenomena using a variety of electron microscopy techniques simultaneously with the introduction of the displacement of atoms from lattice points. This has enabled in-depth studies on such fundamental subjects as the crystalline-to-amorphous-to-crystalline transition, the motion properties of point defects and the one-dimensional diffusion of dislocation loops. Electron tomography studies using HVEMs take advantage of the large observable thickness of a specimen. In addition, by combining different advantages, a number of advanced applications in materials science have been carried out, including analyses of the atomic structure of a reduction-induced reconstructed surface and the atomic mechanism behind the self-catalytic vapor-liquid-solid growth of an oxide nanowire. As long as excellent and invaluable studies that cannot be carried out without HVEMs appear in succession, it is necessary to make the utmost efforts to improve these microscopes.     

级联型变频器在高压大功率电机软启动中的应用

为了解决高压大功率电机软启动技术实现难的问题,文中介绍一种基于单元级联型高压变频器的电机软起动应用方法,利用高压大功率变频器的特点,用其作为高压大功率电机的软启动器,使得高压大功率电机能够平稳、无冲击、大转矩启动。     

半导体激光器在高压反馈电路中的应用

阐述了一种高精度的高压反馈控制电路.它由发送电路将反馈电压实时值转换成串行数字信号,再用它调制半导体激光器发出的光,其光穿过耐高压绝缘层送给接收电路.后者通过光敏二极管和74AHC反相器整形电路获得串行数字信号,然后送给控制器中的单片机,在其软件支持下,实现全闭环控制.所述方法新颖实用,具有参考价值.     

炉用磁控管的阳极电压电流波形与输出频谱特性

本文讨论两种不同整流电源（即半波倍压及全波整流不滤波电源）在不同负载情况下,微波炉用连续波磁控管阳极电压与阳极电流及输出频谱的各种波形,分析了不同电源时电流导通角及频谱的变化。提出了两种不同电源都具有不同于连续波及脉冲波的突特的多基频特性及其成因。     

电子节能灯用高压铝电解电容器的研制

为了提高电子节能灯用高压铝电解电容器的高温高压稳定性,以及耐大纹波电流冲击的特性,采用γ-丁内酯与乙二醇混合溶剂,1,7-癸二酸铵和1,6-十二双酸铵的双溶质体系的工作电解液,并加入适当的添加剂,优化了生产工艺,研制出的产品通过了105℃整灯过压试验3 000 h考核。     

Silicon microsystem passivation for high-voltage applications in DNA chips

DNA chips conform to a field of primary interest, where many different knowledge areas converge into a multidisciplinary effort to develop new devices and methodologies for DNA analysis. In DNA electrophoresis techniques, silicon chips present many advantages (such as the possibility of integrating electronic and optical circuitry, an established know-how on processing, etc.), but they also pose the problem of effective isolation for the application of the required electric fields. In this article, we describe a novel methodology, compatible with device sealing techniques, for electrically isolating a DNA chip.