触发管放电延迟时间的研究

本文叙述了触发管的延迟和抖动时间在实际应用中的意义及其定义,研究了它们受阳极工作电压、间隙距离、气体压力、触发能量与结构等因素的影响,指出了与应用有关的问题。     

神光-Ⅲ原型装置预放钕玻璃高增益自激振荡的分析与抑制

在高功率激光装置的预放系统中,高增益放大单元提供超过106的增益倍数,极易形成自激振荡,降低光束放大倍数、破坏光学元件。基于高功率固体激光系统自激起振的主要判据,通过分析钕玻璃高增益系统损耗与增益的大小,研究了神光-Ⅲ原型装置高增益放大单元的自激振荡问题。分析了系统可能存在的自激振荡腔,指出系统可能存在3个起振的振荡腔。通过采取钕玻璃端面引入倾角、适当的光路调节、加隔离和电光开关等方法,在一定程度上抑制了自激振荡,进行了相应的实验验证,实验结果表明通过上述措施基本消除了自激光问题。     

某能源组件氙灯放电电流波形采集系统的设计

论述了某能源组件氙灯放电电流波形采集系统的设计方法，介绍了大规模可编程门阵列（又称FPGA）EPM9320GC280-15控制波形采集，及10MHZ高速A/D转换器件AD7825的使用方法。     

医用激光器闪光灯的准谐振触发预燃技术

为限制Nd:YAG激光器闪光灯抽运源在触发预燃时的功耗和电磁干扰,以符合国家关于医用电气设备对电磁兼容性的要求,研发了准谐振腔体触发预燃技术。由于脉冲变压器的寄生参量无法消除,会在电路中产生复杂的振荡过程。利用这一谐振特性,通过调节触发频率,使之与谐振频率相同,达到准谐振状态点燃闪光灯。实验证明该电路稳定可靠,其峰值电压可降到10kV以下,远低于同类闪光灯触发电压16kV的标称值。结果表明,该电路完全达到了国家关于医用电气设备对电磁兼容性的标准。     

万瓦连续CO_2激光器的放电稳定性和某些工作特性的研究

本文论述了一台万瓦连续CO_2激光器的放电稳定性和某些工作特性。     

基于事件触发和量化的非线性系统稳定性研究

针对非线性系统的数据采样稳定性问题,文中设计了基于事件触发机制和数据量化机制的神经网络控制器。采样器时刻监测非线性系统,采样信号经事件触发机制检测,满足阈值后由量化器量化传入控制器,经所设计的控制器输出反馈给非线性系统。为降低系统保守性,选取了新颖的分段Lyapunov-Krasovskii泛函,针对系统中所包含的传输时滞,采用时滞分析法将同步控制器求解问题转化为所对应时滞系统的稳定性问题,并结合Jensen不等式,给出了非线性系统稳定性条件。最后通过数值仿真验证了所提出方法的有效性。     

双间隙伪火花开关沿面放电触发材料的测试与研究

本文介绍了一种新型大电流脉冲调制器件——双间隙伪火花开关,它利用介电材料沿面放电进行触发,双间隙导通脉冲大电流,可以用来调制不低于50kV、50kA的脉冲,并能直接用于替换氢闸流管以及高气压火花隙。本文就双间隙伪火花开关沿面放电的三种触发材料进行了相关研究,确定了氮化铝-碳化硅材料具有优良的触发性能与机械性能,解决了触发单元成品率较低的问题,实现了双间隙伪火花开关的产品化。     

Nd:YAG激光电源预燃触发系统

针对 Ｎｄ∶ Ｙ Ａ Ｇ 激光电源的特点, 研制出了一种可靠预燃触发网络系统。氪 （ Ｋｒ） 灯被触发后, 经过一个小电流的缓冲放电, 它类似于一般预燃放电; 但无需长时间保持预燃电流。该预燃网络功耗显著降低, 在低重复率的固体 Ｎｄ∶ Ｙ Ａ Ｇ 激光电源工作中, 其优越性表现得更加完美。     

晶体管恒流全新触发连续固体激光器的氪灯电源

介绍一种晶体管恒流全新触发连续固体激光器氪灯电源。先用一较高电压的辅助电源触发氪灯进入辉光放电 ,然后接通主电源 ,通过控制电路使氪灯自动过渡到弧光放电。为使氪灯正常工作电流恒定 ,光强稳定 ,采用晶体管恒流电路控制氪灯电流 ,从而使整机电路简化     

Stability of discharge series in the plasma display panel

The regularity of the pulsed discharges in the plasma display panel is attributed to processes which automatically damp out perturbations from equilibrium conditions. With rectangular wave excitation, these processes are controlled by the dependence of wall voltage changes during a discharge on the cell voltage at the beginning of a discharge. Conditions for stability and instability are derived for both simple series, in which all discharges are identical, and for more complex series of recurrent discharge sequences, for which the discharges within a sequence need not be identical.     

Design and analysis of a NMOS triggered LIGBT structure for electrostatic discharge protection

A novel NMOS triggered LIGBT (NTLIGBT) structure is proposed for electrostatic discharge (ESD) protection in this paper. The structure utilizes internal NMOS to trigger SCR-like structure in LIGBT. The trigger voltage is significantly reduced because the embedded NMOS causes N⁺-drain/P-body junction being apt to avalanche breakdown. At the same time, the new parasitic PNP transistor including the newly added P⁺-region as a collector forms another path to bleed ESD current and then the conductivity modulation in the LIGBT is weakened. As a result, the holding voltage is increased. So, the proposed NTLIGBT structure has a narrow ESD design window. The simulation results show an improvement of 71.5% in trigger voltage and over 50% in holding voltage comparing with the conventional LIGBT structure.     

Optimization of energy characteristics of inductive discharge in high-frequency ion engines

A procedure for analysis, calculation, and optimization of the parameters of electric system for power supply of inductive discharge is developed. The conditions for the maximum efficiency of the power supply systems in high-frequency ion engines are analyzed. An equivalent circuit of the inductive discharge with capacitive coupling is proposed using the analysis of schemes of different high-frequency ion engines and transformed into a complex equivalent impedance connected in the inductor circuit to calculate matching reactive elements. Equivalent parameters of the plasma of inductive discharge are estimated using the wave model. Calculated and experimental results are used to formulate the main requirements on the laboratory models of the high-frequency oscillators and matching units of the radio-frequency ion engines.     

Measurements of the voltage induced on an overhead power line 20 mfrom triggered lightning

Voltages induced on a 448-m power distribution line by eleven return strokes in three lightning flashes artificially initiated 20 m from one end of the distribution line and the corresponding vertical electric fields at 500 m have been measured. Two types of induced-voltage waveforms were recorded: oscillatory and impulsive. The former exhibit peak values that range from tens of kilovolts to about 100 kV; the latter show peak voltages nearly an order of magnitude larger. Both types of induced voltage waveforms were observed to occur for different strokes within a single flash. Relatively successful modeling of the oscillatory voltage waveforms is presented. Modeling of the impulsive waveforms proved unsuccessful, probably due to those waveforms being in part associated with a failure, perhaps an unexpected flashover, in the measuring system     

工业污水排放远程自动监测系统设计

为了实现远程实时监测工业污水的排放，研究设计出一种通过电话网络传输DTMF信号进行远程控制的智能监测系统。该系统是以单片机AT89C51和DTMF解码电路MT8870为核心元件。给出了主要硬件电路设计，验证了系统的可行性。     

Stability of a sinusoidal-perturbation extremal-control system

A theoretical stability analysis of a single-input sinusoidal-perturbation extremal-control system with output lag is considered. Periodic solutions of the system equations are obtained using the principle of harmonic balance, and their stability properties are investigated. The domains of attraction of the stable solutions are plotted to give the stability boundaries for the system.     

Stability of a sinusoidal-perturbation extremal-control system

The stability is considered of a single-input sinusoidal-perturbation extermal-control system with output lag. The stability boundary of the system is discussed, and some experimental results about its shape are presented.     

Simultaneous amplification of 20 channels in a multiwavelengthdistribution system

Simultaneous amplification of a 20-channel multiwavelength signal using a traveling-wave semiconductor optical amplifier is discussed. The channels occupied a band 34 nm wide centered at 1.54 μm, and 6-8-dB net gains were obtained. Bit-error-rate measurements at 1 Gb/s showed small receiver penalties due to amplifier noise and interchannel crosstalk     

Resonance characteristics of a cavity-operated electrodelesshigh-pressure microwave discharge system

To characterize the resonance behavior of cavity-operated electrodeless high-pressure microwave discharge systems, a microwave circuit is developed that allows high-power network analysis during the operation of the discharge. The frequency-dependent complex impedance of the cavity including the plasma is obtained from a reflection measurement in the range 1.5 GHz-4.5 GHz. This method allows an observation of the actual resonance frequency and the actual vectorial mismatch so that a coupling efficiency >99% can always be achieved with proper adjustment of the operation frequency and coupling probe. Experimental results with a cylindrical TM₀₁₀ cavity and a coaxially situated discharge show a decrease of the resonance frequency with increasing power (increasing plasma temperature, electron density, and electrical conductivity) depending on the discharge geometry and the plasma composition. In accordance with a simple one-dimensional model, the Q factor passes through a minimum at medium power levels, where the cavity discharge system absorbs the microwave energy most effectively     

华为NE20系列路由器尽显灵动刚毅之美

网络的发展演进,多业务承载的需求,需要一种性能卓越、功能丰富且在复杂业务环境下表现稳定的路由器产品。NE20系列路由器正是为满足这些需求而量身定制,定位于专线大客户、园区网NAT出口、宽带接入网汇聚等应用领域。在这些复杂的应用领域,NE20系列路由器充分展示了它既灵活多用又坚毅稳定的优良晶质,尽现灵动刚毅之美。