Development of remote control and monitoring system for the FE gun in HVEM

This paper describes a control and monitoring system for the field emission (FE) gun in the high-voltage electron microscope (HVEM), where the whole FE gun system is located inside a pressure vessel and is floated on a high voltage of 1 MV. The operating condition of the FE gun system is controlled and monitored mainly by a bi-directional communication system between ground and high potential through optical fibres. A mechanical driving system by combination of insulator rods and stepping motors is partially used as a control system for FE gun operation. The monitoring system developed here also functions as a safety circuit that detects abnormal situations, such as an abnormal deterioration of vacuum, and protects the FE tip against fatal damage. The fundamental performance of the microscope has been tested for transmission electron microscope (TEM) and scanning TEM operation modes.     

有源电子式电流互感器高压侧电源的研究

电流互感器是电力系统中的重要设备,介绍一种适用于有源电子式电流互感器的悬浮式直流电源的设计原理。提出一种用补偿线圈和充电电池相结合的方法对母线电流取能方式进行改进的新方案,使电源在更宽的一次侧电流动态范围内满足电子式电流互感器对电源的要求。实验结果表明,该电源能够满足高压侧电子电路的供能要求。该方法是目前解决有源电子电流互感器高压侧电源问题的有效方法之一。     

简易数字控制宽带放大器的设计与实现

设计一种数字控制的高增益宽带宽放大器,提出了采用多个放大器直接耦合级联方式,通过理论分析合理选择各级增益的分配,明显改善了放大器的低频特性,极大地提高了增益范围。系统由前置放大电路、程控增益放大电路、通频带选择电路、功率放大电路、单片机控制电路以及电源模块6个部分组成。其中通频带选择电路由两路巴特沃斯低通滤波器组成,可实现通频带的切换;功率放大电路由多个高速缓冲芯片BUF634并联组成,扩大了电流输出范围,实现了功率放大;单片机控制电路以MSP430G2553为主控芯片,使用液晶12864实现显示功能,人机界面友好。经测试,本系统能够完成0~10MHz频率范围内的0~80dB增益步进可调功能。在增益为60dB时,输出电压噪声峰峰值小于0.3V,很好的完成了系统的设计指标。     

某火炮故障检测系统设计及精度问题研究

火炮故障检测系统检测范围有限和检测精度低是火炮故障诊断系统的两大缺陷,针对现有火炮检测系统检测精度低的问题,从电路设计、A/D采集电路设计以及液晶显示等方面分析了影响系统检测精度的主要因素,并提出了多种改善检测精度的方案。针对现有火炮检测系统检测范围有限的问题,提出了一个可对炮控箱、操纵台和瞄控箱、电源、开关以及电位旋钮等多位置发生的故障进行检测的火炮综合故障检测系统,并对该系统相关的硬件和软件进行了设计。测试实验表明,该系统功能完善,通用性好,改善系统检测精度的方案实用性强,对于提高我国的火炮故障检测水平具有积极的意义。     

晶体管音频功率放大器电源的研究--传统电容滤波整流电源的研究(一)

分析了晶体管功率放大器对电源的要求,提出了理想功放电源的条件,从理论和实践两方面对传统电容滤波整流电源的负载特性进行了分析,找出了影响其性能的主要原因,并指出这类历史悠久、应用广泛的传统电源,离理想功放电源的要求相去甚远。     

Cuber predistortion linearizer for relay equipment in 800 MHz band land mobile telephone system

New relay equipment for a tunnel relay system used in an 800 MHz band land mobile telephone network has been developed. Significant improvements in size and power consumption have been achieved using a predistortion (PD) circuit to compensate for third-order intermodulation (IM) distortion generated in the power amplifier. This predistortion circuit features a simple configuration and easy adjustment, as well as high distortion reduction performance. The circuit configuration is derived from an analysis based on a complex power series representation of input-output nonlinearities for microwave transistor amplifiers. This analysis shows that two kinds of nonlinearities, AM-AM and AM-PM conversions, are uniquely related through the third-order distortion phase, In addition, an automatically controlled predistortion system is introduced to establish an adjustment and maintenance-free compensator. Using the developed predistortion circuit, a stable distortion reduction of more than 20 dB per 25 MHz bandwidth has been attained.     

基于LP3913的便携设备电源管理系统

介绍了多功能电源管理单元器件LP3913的基本结构和工作原理,并以S3C2440A处理器为控制核心设计了基于LP3913的电源管理系统.该系统设计采用USB外接电源和锂离子电池供电,整个电路结构紧凑,功能完善.     

石油测井仪器电流检测系统分析

在测井仪器的研发期间,对仪器的功耗要进行监测,利于可以科学的给仪器搭配适合的电池,为此设计了可以在大动态情况下,连续的对直流的小电流进行监测的检测系统,对于系统有连续监测小电流的独特需求,设计出了运用高输入阻抗的方法和差分运放的I/V转换方法选用放大信号、多级硬件的电路滤波和数字的滤波相综合形式的制止干扰的方法,主要是制止系统内的噪声和系统外在的工频干扰;在此之外还运用软件来达到自动量程的效替来实现大范围的电流检测要求,通过实验来实现使用的需求.     

一种基于无线传感器网络的生物信息检测系统节点电源设计

针对电源系统需要为系统中微处理器、传感器、信号调理电路、无线通讯模块等提供工作电源的目的,提出一种生物信息检测系统中无线传感器网络（WSN）节点的电源设计方案。除了通过内部3.7 V锂电池,振动产生的机械能也可以用来提供能量。系统工作过程中能自动对供电方式进行选择,并完成对锂电池的充电任务。节点采用带有8051内校的CC2430无线射频芯片,通过有效的动态电源管理和唤醒休眠机制的软件设计,针对生物信息检测系统实现了一种低功耗的能量自供给的无线传感器节点电源设计。     

Smart dual battery management system for expanding lifespan of wireless sensor node

Wireless sensor nodes have huge energy demand for their operations; they are deployed in remote locations for various applications like weather, industrial, satellite, construction, banking, and medical. Sensor nodes require continuous or uninterrupted power supply during their life cycles. When the available renewable power sources are not sufficient to run the system, the batteries are required to deliver a continuous and uninterrupted power supply. The main focus of proposed model is to design and develop a smart dual battery management system along with a hybrid energy harvesting model that can provide reliable and efficient power support to the sensor node. The problem under consideration also focuses on reducing the state of health degradation of batteries by applying a smart battery charging methodology using an ANFIS (adaptive neuro-fuzzy inference system) controller. The proposed power management system ensures and meets the expected objectives such as switching of power sources, smart battery charging methodology (constant current and constant voltage [CC-CV]), and dual battery power support using ANFIS controller. The result was obtained through the simulation and hardware prototype of the proposed system work flawlessly to meet the desired objective with partial charging and discharging of batteries for the prevention of battery degradation and also enhance the lifespan of the batteries.     

便携式野外充电器的设计

为了解决手机电源突发断电,满足手机随时随地进行充电的目的,设计了一种太阳能及手摇式多功能手机充电器。使用太阳能电池板,经电路进行直流电压变换后给手机电池充电。手摇发电机产生波动较大的电压后,利用电压变换电路将输入电压整流、滤波、稳压后,得到稳定的充电电压。对220V工频交流电进行整流、滤波、稳压后得到充电电压。后经充电管理电路给电池充电,充电完成后自动停止。该设计具有适用于旅行中野外使用的特点。     

Ku波段高效率脉冲行波管的研制

简要介绍了Ku波段高效率脉冲行波管的设计、CAD计算和测试结果。通过对电子枪、聚焦系统、慢波电路、电子注和慢波线高频场大信号互作用的计算、收集极的设计,获得了符合新雷达系统技术指标要求的整管。实测结果为:在Ku波段2 GHz频带范围内,等激励、脉冲输出功率大于2.2 kW、效率大于30%。     

红外无线语音系统的设计与实现

本设计制作的这个系统是红外无线语音传输系统.在系统设计时,使用的是一对850nm波长的红外光发射、接收管.利用它能够将声音进行传递.在用手机的插头作为输入信号在通过电路的调试来实现语音信号传输,从而实现了定向,然后我在进行红外光收发系统的设计.通过测试和查阅资料可以知道,5m的传输距离是红外通信保证无明显失真情况下的极限距离.通过放大和滤波电路,此时电路主要由LM-386所搭建.同时我们还加了一个转制装置来实现90°的转变,最后输出端的喇叭中可以听到输入的语音.     

电力线载波通信EMI滤波电路研究

电力线通信是一个正在发展的崭新学科,但由于电力线传输的无屏蔽性,给电力线通信带来严重的电磁干扰与电磁兼容问题。在深入分析了电力线通信系统产生电磁干扰的主要原因的基础上,对EMI滤波电路进行了设计研究,并通过实验验证了该滤波网络对于抑制电力线载波通信EMI的可行性。     

基于光路失调原理消除笔形光束的危害

分析高功率激光器中笔形光束的成因及其潜在危害的规律,提出一种减少(或消除)空间滤波器中笔形光束的技术措施——倾斜透镜法。用增广矩阵法计算非共轴光路笔形光束会聚点位置并分析其变化。以高功率激光系统的空间滤波器为例,报道追寻失调滤波器中鬼点和消除笔形光束的设计、计算结果。结果表明,采用两透镜非同轴构型,选取适当的滤波器设计参数,并适当倾斜透镜L2,能有效地避免笔形光束对高能激光系统造成的危害。     

Design of interface circuits with electrical battery models

In designing interface circuits to a battery, often the battery is assumed to be a simple voltage source. However, the battery itself has internal parameters. This means that the internal parameters of the battery models need to be considered for the interface design. Several electrical battery models are presented. Then, using these electrical battery models, the analysis and the design of the interface circuit are described. Analysis and experimental results show that an electrical battery model which reflects battery characteristics has to be used for the optimal design of the interface circuit. Finally, the analysis results indicate that the required size of the condenser filter can be smaller with battery power supplies than with other power supplies, such as bridge-type AC source DC power supplies     

干式电力变压器振动信号调理电路的设计

基于振动法的变压器状态监测系统通过安装在变压器器身上的振动传感器来测量运行中的变压器的振动信号,通过对干式电力变压器振动特性的分析,得出振动量的量化特性,方便了调理电路的参数设计.振动信号的调理过程,采用一种内装IC的加速度传感器YD35D,适合用来测量电力变压器的振动信号,通过电荷放大器、增益放大电路和滤波电路将加速度信号转变成微处理器可采集的0-5v的模拟电压量,较为详细地介绍了信号处理各部分电路的设计及电阻电容的参数计算公式.通过电子电路仿真软件Multisim对电路参数进行了合理配置,仿真结果表明系统的信号幅度控制合理,滤波效果明显,电路设计具有实际应用价值.     

Novel current transducer in a single-phase active power factorcorrection system

In line-fed converters implementing power factor correction, the current shaping process requires input current sensing, commonly obtained using dedicated power components as shunts or current transformers. This work presents a current sensing circuit applied to active power factor correction with boost topology, which does not use the previous components. The sensing element is an inductor placed in the input filter, needed to comply with electromagnetic emission standards. The operating principle of the proposed sensing circuit is then extensively discussed, and analytical formulation of the frequency response is given for real conditions. The influence of transducer error on the performance of the power factor correction (PFC) system is also analyzed. Theoretical analysis shows that a system with a low total harmonic distortion (THD) can be achieved, and this is confirmed by experiments on a laboratory prototype     

基于嵌入式技术的超低功耗红外光通信系统设计

为了解决红外光通信存在传输方向单一和消耗功率高问题,设计基于嵌入式技术的超低功耗红外光通信系统,系统单片机使用改进型STM32,将超低功耗红外发射装置嵌入到红外光通信系统中,该装置通过固定载波频率将输入音频信号,通过发送校准模式和音频传输模式调制为高频方波信号后,采用红外光管向外发射信号,并在电路中增加功率负载电流实现限流,降低红外光发射电路功耗。红外接收装置通过共射级放大电路接收信号,采用脉冲宽度调制(PWM)调制信号,实现信号高质量、低功率传输。红外通信模块实现红外发射装置和接收装置间信号的双向传输。系统采用保护驱动模式、中断模式与用户模式的红外通信协议栈,最大程度降低系统通信能耗,提高系统通信效率。实验结果表明:该系统能够实现信号和温度信号的有效传输,在休眠和正常运行时的功耗均较低,误码率低,是一种功率消耗低、通信质量高的红外光通信系统。     

Custom design of a VLSI PCM-FDM transmultiplexer from system specifications to circuit layout using a computer-aided design system

The computer-aided design of a VLSI PCM-FDM transmultiplexer is presented. The entire design process, from system specifications to integrated circuit layout, is carried out with the aid of specialized computer programs for the analysis, synthesis, and optimization at each design level: the filter network, the architecture, and the circuit layout. These CAD tools support a top-down custom design methodology based on bit-serial architectures and standard cells. A customized architecture is constructed which is integrated using a 5-/spl mu/m CMOS cell library. The results are compared with a fully manual design and demonstrate the power of architecture based computer-aided design methodologies for VLSI filtering. By combining both synthesis and optimization aids at each design level it is possible to achieve a high degree of automation while retaining an efficient use of silicon area, high throughput, and moderate power consumption.