以动态调试开展数字逻辑实验教学的体会

目前多数大专院校所使用的逻辑实验箱,基本上仅具备静态调试的条件.致使目前本课程的实验课与理论课有一定的脱节现象,实验内容和方法的改革受到限制,实验效果和成功率均不理想.首先从实验内容来看,诸如序列检测电路、串-并或并-串转换电路、电平异步电路、脉冲异步电路等各种多输入变量的时序电路,均无法在上述实验箱上方便地开出相应的实验.     

模拟(ACL型)、数字(DCL型)电子技术实验箱

1　ACL- 型模拟电子技术实验箱“ACL - 型模拟电子技术实验箱”是“模拟电路”实验的基本教学仪器 ,产品性能稳定可靠 ,保护手段齐全 ,实验方便灵活 ,可根据需要扩充实验项目。面板上附有多种元件 ,便于学生增加感性认识。实验完全由学生进行元件的排列、接线等 ,可培养学生的动手能力。教师和学生还可利用此实验箱进行课程设计以及科研开发提高设备的使用率。1 .1　主要特点和性能1 )实验箱结构采用铁质喷塑 ,外形为长方形 ,有把手和支撑脚 ,便于移动和存放。2 )面板采用 2 mm厚印制板 ,正面喷漆 ,印有元器件符号表示各模块功能 ,反面…     

教学仪器系列介绍（二）：现代数字系统实验箱

本文继上期介绍的电工电子教学实验台各型号的产品特点、性能及所开的实验项目等，着重介绍三种现代数字系统实验箱。     

基于ELVIS Ⅱ~+的信号与系统实验设计及实现

目前"信号与系统"课程实验大多采用实验箱实现,其不足之处是学生不能直接触电子元器件、自由选择元件、搭建自行设计的电路。ELVIS Ⅱ+集成了12套常用虚拟仪器,具有原型开发板。本文将其用于信号与系统实验,代替传统实验箱以弥补其不足。本文介绍了所设计的实验内容及相应的实现方案,指出了实验中存在的一些问题,并提出了相应的解决方法。     

教学仪器系列介绍（三）：电机系统教学实验台

今年本刊第1、2期已分别介绍了电工电子教学实验台及现代数字电路实验箱（在系统可编程逻辑器件实验箱）的内容,本期以教学仪器系列介绍（三）介绍电机系统教学实验台。本公司目前推出的产品有：（1）EEL－I豪华型电工电子教学实验台改革（2）EEL－I、！、巨型电工电子教学实验台（3）MDL一巨型现代数字系统实验箱（4）JDEE－7型在系统可编程器件实验箱（5）JDEE－32型在系统可编程器件实验箱（6）SSL一！型信号与系统实验箱（7）DCL－l型数字电子技术实验箱（8）ACL－I型模拟电子技术实验箱（9）MEL－！、！型电机系统教学实…     

应用型模块化单片机实验箱的设计

为弥补传统单片机实验箱的不足,培养应用型人才,研制了一套模块化的实验箱。该实验箱由单片机最小系统和五个模块组成,通过模块组合可以完成基础实验和设计性实验,还能满足课程设计、毕业设计、竞赛及教师科研的需求。该实验箱能充分调动学生的积极性,提高学生创新实践能力。     

对数字电路实验箱的改进

在教学过程中发现数字电路实验箱不能做ROM、A／D和D／A实验,原因是设计上的固有缺陷。为提高数字电路实验箱的利用率和可靠性,本文针对数字电路实验箱存在的问题,提出了电源和面板改进方法。文章阐述实验箱的改进方案及电原理图。改进后数字电路实验箱增加了ROM、A／D和D／A实验内容,达到良好教学效果。     

教学仪器系列介绍（一）—电工电子教学实验台

求是公司自1996年推出EEL－I型电工教学实验台三来以来。我们本着“求是、创新”的浙大校风，产品从使用一改进号再使用一再改进，已趋完善，无论是产品的外型美观程度还是性能指标及实验数据的准确性都位居同行前列。开发和推出了许多全国一流的教仪设备，成为国内众多大专院校新建和改造实验首选之产品。本公司目前推出产品有：（l）EEL－I豪华型电工电子教学实验台；（2）EEL－I、巨、血型电工电子教学实验台；（3）MDS一巨型现代数字系统实验箱；（4）ACL—互型模拟电路实验箱；（5）DCL－I型数字电路实验箱；（6）SSL－I型…     

从仿真软件到虚拟电工电子实验室

以Multisim仿真软件为例,介绍仿真软件在实验室中进行电工电子实验的验证与设计的方法,从根本上改变硬件实验的传统做法。现在国内大多数学校仍主要采用实物元器件进行硬件连线测试,大多数采用面包板或者各种实验箱进行实验。在计算机快速发展的今天,虚拟器的发展已经与计算机的发展同步,由虚拟器软件定义仪器功能,从而构建所需的虚拟仪器教学系统,其灵活、可重复性强的特点使实验教学方法、手段更先进。在职业类学校的电子实验室中,虚拟仪器将发挥越来越重要的作用。     

电子设计工程师认证实操实训基础系列讲座(3) 第二讲 EDP电子工程实训的软件开发(上)

<正> 现代电子工程设计中,大部分系统已离不开各种微控制器的参与。作为系统控制核心的微控制器单元,其正常的运行少不了软件。本文即是以EDP实验箱为背景,介绍电子工程设计中单片机软件的开发流程与方法。单片机软件的开发工具具有多样性,不同类型的单片机软件开发工     

Optical detection of charge modulation in silicon integrated circuits using a multimode laser-diode probe

This paper reports on the detection of sheet charge densities in silicon devices using an improved noninvasive optical probe based on the detection of free-carrier optical dispersion using a multilongitudinal-mode 1.3-µm semiconductor laser. The improved system incorporates a differential detection technique and a Wollaston prism that allows the use of the multimode laser. These changes increase stability, sensitivity, and bandwidth, allow near shot-noise limited operation, reduce required optical power, and simplify the apparatus. The technique can be applied to probe electronic signals or, conversely, to modulate light using controlled electronic signals. Simple demonstrations of each application are presented.     

物联时代智能车载电子系统发展分析

智能车载电子系统既要满足苛刻的使用环境要求,又要集电脑、通信、导航等多种功能于一身,还要能与底层汽车电子系统进行通信,监控车辆运行状态。本文介绍了物联网络时代智能车载电子系统的技术特点、运行组织与运营模式,并根据我国宏观经济和汽车市场的发展,提出了具体的技术可行性实施案例,并进行了经济性分析,结论表明,智能车载电子系统将为整车企业、电信运营商、各类软硬件及内容提供商等公司带来巨大的增长点。     

Noise characteristics of nonlinear semiconductor optical amplifiersin the Gaussian limit

This paper addresses noise properties of nonlinear semiconductor optical amplifiers. From a basic point of view, noise properties of nonlinear optical amplifiers are sufficiently different from those of linear amplifiers to warrant detailed modeling which has not been formulated previously. From a practical point of view, nonlinear semiconductor optical amplifiers are important for future all-optical signal-processing applications which may involve the operation of these devices in a saturated regime. Nonlinear amplifiers are also common in systems operating near 1300 nm and in integrated booster amplifiers. Under nonlinear operating conditions, amplifier noise contains a narrow-band contribution that comes about due to the nonlinear coupling of noise and gain. The more conventional broadband spontaneous noise also changes as the inversion factor becomes power-dependent and varies along the amplifier axis. We analyze noise in nonlinear amplifiers in the Gaussian limit (meaning, for fields consisting of large photon numbers) for CW or NRZ modulated signals and separately for short pulses. We consider the case of a single input as well as configurations of multi-input signals interacting via four-wave mixing. Using a specific detection system for the calculations of electronic signal-to-noise ratios, we demonstrate a reduction in the narrow-band electronic noise due to saturation in the single input case. We also demonstrate a vast advantage of using short pulses in four-wave-mixing applications     

A New Two-Three-Phase Voltage-Controlled Oscillator

The initial aim of the work has been the development of an inexpensive quadrature oscillator which can operate as a rapidly responding voltage-controlled oscillator (VCO) in two phases. Such rapid operation in quadrature is needed in association with quickly operating phase-locked loops for frequency synthesizers and similar applications. Other applications, where the relatively large speed is not essential, but where the phase shifts between various outputs should be precise, are mentioned in concluding this section. The electronic realization is made relatively cheap by proposing a replacement of the instantaneous amplitude measuring operation of square and sum (x2 + y2) (associated in the process of amplitude stabilization) by an operation of three-phase rectification. This leads to the construction of a versatile instrument which generates three-phase signals as well as two-phase signals (the two-phase signals are both sinewaves in quadrature and also square waves in quadrature). All these waveforms are capable of participating in the system performance as a VCO at a relatively large rate of frequency changes. A reversal in the order of phases when the frequency-control voltage crosses zero is also exhibited. This is needed in applications in industrial and power electronics. Our main aim now is to use the instrument in association with a precisely stabilized quickly responding cyclo-converter. Other possible applications of the instrument are in the field of precise measurements (for example, in the detection of signals by lock-in amplification there exists a frequent need for quadrature operation) and in telecommunication.     

16×16 optical-fiber crossbar switch operating at 0.85 μm

An optical-fiber crossbar switch has been constructed using fully integrated GaAs optoelectronic receivers, custom monolithic GaAs laser drivers, and an electrical 32×32 silicon crossbar switch. 470 Mb/s operation has been achieved with a bit error rate of less than 10^-12. The approach uses a monolithic GaAs optoelectronic integrated receiver to convert optical signals into electrical signals that are fed into an Si 32×32 electronic crossbar switch. The switch outputs are used to drive laser transmitters consisting of a custom monolithic GaAs IC laser driver and a 0.85 μm GaAs/AlGaAs laser. The system could be reconfigured in 1 μm, limited by the control logic, with the switch chip capable of reconfiguration in 35 ns. No errors are induced by reconfiguration     

一种基于空间到达角的卫星电子侦察信号分选方法

在建立简化的卫星电子侦察空间模型的基础上，提出了一种利用空间到达角分选卫星电子侦察信号的新方法。通过仿真实验验证了这种方法的可行性。该方法可用于密集信号的预处理。     

A new low-power current-mode MOS only versatile precision rectifier

In this paper, a new low-power versatile current-mode rectifier is proposed. As a salient feature, the proposed rectifier provides two positive half-wave, two inverting negative half-wave or two full-wave outputs from the same configuration. The proposed circuit employs only a dual-output second-generation current conveyor (DO-CCII) and a core rectifying circuit consisting of twelve MOS transistors. The input and output signals are current. Favorably, by adding two additional transistors, the proposed rectifier can also rectify voltage signals with electronic tuning capability. The simple and MOS only structure of the proposed circuit is highly attractive from integration point of view. In spite of providing multiple outputs at the same time, the proposed rectifier enjoys low power consumption. PSPICE simulations using 0.18 μm CMOS parameters and supply voltage of ±0.9 V demonstrate a precise operation and good temperature stability.     

一种改进的脉冲幅度比较测量法

直流电压比较法和高采样数表法可对脉冲幅度进行准确测量,但仅适于周期低频信号,应用受到局限。本文采用常规电子仪器,提出了一种改进的脉冲幅度比较法,对其原理、方法和特点进行了阐述,并结合具体实例给出了不确定度分析。该方法不仅应用方便、准确度高,而且适于高频单次等各类脉冲的准确测量,有广阔的适用性。     

A novel amplitude-to-phase converter for sine/cosine position transducers

Resolvers and various other types of sine/cosine encoders are used for both angular and linear position sensing. These devices provide analogue signals in the form of the sine and the cosine of an angle?θ?related to the position of the moving part of the transducer. A novel converter is described for the linearization of the sensor signals. The scheme converts the co-sinusoids into a nearly perfect triangular signal from which?θ?is determined using simple linear equation. The proposed converter makes use of the alternating pseudo-linear segments of the sensor signals, together with a dedicated and simple linearization technique to further improve the linearity of these segments. This enables unambiguous determination of?θ?over the full 360 degree range, with an absolute error of non-linearity of 0.041 degree. The conversion technique may be implemented numerically or electronically. The proposed converter was built using basic analogue electronic circuitry, and was successfully tested using both an electronic transducer model and a commercial resolver. The principle and theory of operation, computer simulation, and experimental results are given.     

雷达信号包络特征的检测与分析

雷达信号的分类识别是电子对抗的一个重要方面 ,而雷达信号包络分析是识别它的一种重要方法 ,它利用检测设备截获敌方雷达信号 ,通过分析它的包络特征来识别雷达信号以便于干扰或反干扰。采用平滑、微分的方法对包络进行处理 ,获得它的各项参数信息 ,从而达到对雷达信号识别的目的