转换器

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

The computer separately connects and controls the I/O end and A/D converter; the I/O end connects and controls the X, Y axis driving circuit and the semiconductor laser; the X, Y axis step-by-step driving circuit connects and controls the X, Y step-by-step electrical machines to control the dimensional platform; the beam of the semiconductor laser passes through the focusing drawtube with 0.1mm diameter to form the facula with the diameter less than 0.1mm; the facula irradiates on the detector surface of the XY dimensional displacement platform to produce the corresponding electric signals; the detector surface connects the A/D converter through the amplifier; the electrical signal is amplified and is converted into the data signal by the A/D converter and is sent to the computer for processing.

由计算机分别连接并控制I/O端口和A/D转换器，I/O端口分别连接并控制X、Y轴步进电机驱动电路和半导体激光器，X、Y轴步进电机驱动电路分别连接并控制X、Y轴步进电机，从而控制二维位移平台，半导体激光器的光束经过设有直径0.1mm小孔的聚焦镜筒形成＜0.1mm直径的光斑，光斑照射于设在XY二维位移平台上的探测器表面使其产生响应的电信号，探测器表面经放大器连接A/D转换器，电信号经放大器放大后，由A/D转换器转换为数据信号送计算机处理。

The effect of this modeling method is proved by appling it to the analysis of a fly-back ZCS-QRC. The result show that the proposed method can give important physical insight of the relationship between the compensator and the controlled plant.

为了实际验证这种模型化方法在分析设计上的有效性，本文以一返驰式直流—直流转换器为例予以详细分析，并配合MATLAB的模拟，结果证明这种模型化方法不仅能够简化具有多重回授的转换器分析，并且对补偿器与转换器性能间关系的了解有所助益。

In the data acquisition system, CD4051 and AD574- the A/D transform, are used as hard core to receive the signal from the infra-red ray temperature sensor; the data acquisition depend on CPU; in the keyboard/ display system, a 74LS48 as the driver to drive LED works; in the warning circuit, I used two color LED and a buzzer as one unit to work; DAC0832 converter is the center of the D/A transform; execution unit, I used DDZIII type electromotive unit; the auto-man, it is a disabling of the other control circuit, this can secure production all the time.

在数据采集部分，以多路开关CD4051和AD574模/数转换器为核心接收来自红外线传感器的信号；数据处理依赖CPU；键盘/显示部分，以74LS48驱动LED数码管工作；报警单元，采用了双色LED加蜂鸣器的组合；D/A转换采用了DAC0832转换器；执行器采用DDZIII型电动执行器；手/自动切换装置则屏蔽了之前的电器部分，安全可靠。

The multipeak NDR device can be widely used in multiple valued logics, and analog to digital converters. We obtain a multiple\|valued memory unit through the multipeak N...

并且利用它的折叠的I V特性，实现了一个 4位的FlashA D转换器，与传统的FlashA D转换器相比，SET MOSFET的A D转换器大大地简化了电路。

ICL(7106)3_(1/2) bit A/D convertor through the encoder convert the sectional code into BCD code. The BCD output is interfaced with the microcomputer system,when through se- veral aualog channel qnantity is collected we can use the multiplexor. Our experiment has proved that the system has simple circuit with reliabe operation and it is cheap.

本文介绍了 ICL(7107)3_(1/2)位 A/D 转换器段码输出与微机系统的接口电路，ICL(7106)3_(1/2)位 A/D 转换器经编码器，将段码转换为 BCD 码输出与微机系统收接，当对多个模拟量进行检测时可应用多路开关，实验证明联接线路简单，运行可靠，装置便宜。

The measured radiation patterns of the mode coveter agree well with the calculated results, which indicate that the out-put modes of the mode converter are the same as the simulated results.

实验测得模式转换器的辐射方向图轴向最大，与数值计算结果吻合良好，表明实验中模式转换器的输出模式与数值计算结果一致，从而验证了同轴插板式模式转换器的可行性。

Sources of error in pipelined ADC and accuracy requirements of pipeline stage have been discussed in this thesis.

基于CMOS图像传感器中芯片级模数转换器高速、低功耗的要求，本文剖析和比较了三种典型高速模数转换器功耗，以确定选取流水线模数转换器。

Multi-conductor coupled-line Marchand baluns and broadband frequency doublers and mixers are presented in this dissertation. This research focuses on the development of miniature broadband frequency conversion circuits including frequency doublers, fundamental down-conversion mixer, and IQ-demodulator.

本论文主要是讨论多金属耦合线马逊平衡不平衡转换器及宽频的倍频器及混频器，研究方向是著重於发展包含倍频器、降频器及正交解调变器在内的微小化宽频频率转换电路。

Its complete product line, fiber-optic network, both external power supply type also has built-in power type, both stand-alone also has the standard 19 rack-mount products, covering Ethernet, Fast Ethernet, Gigabit Ethernet and ATM network used in fiber-optic transceivers, fiber optic switches and fiber optic modems and other equipment. early in 1999, netLINK first time in Greater China to launch a technology leader in the industry have the adaptive function of 10/100 Fast Ethernet Media Converter (HTB -1100 series), and its excellent cost performance by customers. October 24, 2001 to 27 in Shanghai 2001 International Electronic Products Exposition and fifty-eighth session of Electronics Show , the Haitong exhibited Netlink Technologies Limited and the exclusive agent of Nufiber company, CTS Corporation a full range of fiber-optic network products, as well as Intelligent Network standard 16-slot rack-mount fiber optic media converter, RS-232/422/485 up mode / single-mode fiber converter and other new products, attracted the attention of the industry and well received by the audience and the fiber-optic network customers.

其光纤网络产品系列齐全，既有外置电源型也有内置电源型，既有独立式也有标准19机架式产品，涵盖以太网、快速以太网、千兆以太网和ATM网络用的光纤收发器、光纤交换机及光纤数据机等各种设备。1999年初，netLINK首先推出当时在大中华区业界处于技术领先的有10/100自适应功能的快速以太网媒体转换器（HTB-1100系列），并以其优异的性能价格比广受客户的欢迎。2001年10月24日至27日在上海举行的2001国际电子产品博览会和第五十八届电子产品展览会上，海通科技有限公司展出了netLINK和独家代理的Nufiber公司、CTS公司全系列的光纤网络产品以及智能网管型16槽标准机架式的光纤媒体转换器、RS-232/422/485至多模/单模光纤转换器等新产品，深深吸引了业界的注意和广受观众和光纤网络客户的欢迎。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。