查询词典 analog to digital

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。

As a private mobile communication system, The digital trunkingmobile communication system was boomed in 1990's, and before this, the appliedprivate mobile communication systems in market are almost the analog systemwith analog voice and digital signalling. And there are no data referring to thesystem design and parameters chosen. It includes the wireless channel accessalgorithm of the mobile terminals, single base station capacity in large regional networks, link designing schemes between the switching control center and basestation as well as the study of the service quality for the multiple traffic. Theseindispensable parameters in design a digital trunking communication system arestudied in this dissertation and some instructive achievements can be got. To provethe correction of the theoretical study, the result was tested with the popularsystem of pan-European digital trunking communication system.

数字集群移动通信系统是九十年代中、后期兴起的专用移动通信系统的一种新体制，在此之前国际、国内市场使用的都是数字信令、模拟话音集群移动通信系统其涉及领域是模拟体制，对数字集群的系统设计的有关参数、方法等的选用及其性能表现并无成熟的文献可供参考，如移动终端的无线信道接入算法、大区组网单基站系统的容量、基站和交换控制中心间的链路设计和多业务种类的服务质量等都是数字集群基站子系统进行设计和开发必须解决的关键技术。

This high voltage electrostatic precipitation controller has 7 channels of analog input,2 channels of analog output, 12 digital inputs and 16 digital outputs. The analog input includes primary current, secondary current, primary voltage, secondary voltage, etc. Controller uses MAX 187 as the A/D converter, which ensure the sampling speed and the conversion precision in the same time. The processor unit is RCM2250 module. Rabit 2000 processor, a 128K SRAM and a 256K Flash Rom are integrated in RCM2250, which improves the performance of pricipitation controller. MAX504 is used to produce the 4~20mA current output.

模拟量输入采集的信号有升压变压器一次电流、一次电压、二次电流、二次电压等，采用12位逐次比较式A/D转换器MAX187，兼顾采样速率和转换精度；中央处理单元采用以8位嵌入式处理器Rabbit2000为基础的RCM2250模块，外扩128KSRAM和256K Flash ROM，内部资源丰富，提高了控制器的整体性能；模拟量输出采用内带基准源的10位电压输出数模转换器MAX504，实现了标准4～20mA电流信号输出；控制器通过控制算法在相应开关量点上输出可控硅的触发脉冲。

10 Multifunction Intelligent DAQ using LabVIEW FPGA, 8 analog inputs, independent sampling rates up to 200 kHz, 16-bit resolution,±10 V,8 analog outputs, independent update rates up to 1.0 MHz, 16-bit resolution,±10 V,96 digital lines configurable as inputs, outputs, counters, or custom logic atrates up to 40 MHz,User-defined triggering, timing, and onboard decision making with 25 ns resolution,1M gate reconfigurable I/O FPGA for parallel processing power

2.10 使用LabVIEW FPGA模块的可重新配置多功能I/O，8路模拟输入、200 kHz同步采样率、16位分辨率、±10 V，8路模拟输出、1 kHz同步采样率、16位分辨率、±10 V，96条可配置的数字线，具有40 MHz输入、输出、计时器或自定义功能，25 ns分辨率的可配置触发、定时、板载决策，1百万门可重新配置I/OFPGA，带有82 kB嵌入式RAM

This dissertation introduces the whole scheme、the hardware electro circuit design and software design, the result of experiment on salinometer is preferred at the end of the dissertation. Salinometer is base on SOPC technology, and use digital technology to design circuit: the excitation source for balance bridge is generated by digital method, its shape、amplitude and frequency can be control by digital signal, the standard branch of bridge is composed of three digital-analog-conversion, and uses the method of successive approximation to regulate the balance of bridge.

盐度计以SOPC技术为基础，通过数字化方式设计测量电路：电桥的激励源由数字化方式产生，激励源的波形、幅值和频率等可由数字量控制；平衡电桥标准支路由3个数模转换器组合实现，测量时以逐次逼近的方式调整电桥的平衡度；检测电桥平衡度的高灵敏度数字检流计同样以数字化方式设计，它的增益由程序控制，将电桥的输出电压数字化，以软件判断电桥平衡度。

It is a network terminal which is connected with digital television; it is used for transforming digital signals to analog signals. After decoding the digital constringent video and audio signals, it will engender analog video and audio signals. Consequently, it can provide high quality television program for audiences.

它是一种与电视机连接的网络终端设备，用于将数字电视信号转换成模拟信号，它通过对数字化压缩的图像声音信号进行解码还原，产生模拟视频和声音信号，以提供给观众高质量的电视节目。

The working principle of a novel short st roke linear DC motor wit h permanent magnet s is presented. Mixed digital - analog cont rol approach based on DSP ( TMS320L F2407A) is proposed. Displacement detecting and cont rol technique are discussed. Displacement detecting circuit s , digital - to - analog converter (DAC7641) expanded circuit s and cont rol software are given.

阐述了一种新研制的短行程永磁直流直线电机的工作原理，提出了基于DSP ( TMS320L F2407A)的短行程直流直线电机数、模混合伺服控制系统方案，重点对直线电机的位置检测及控制技术进行了研究，给出了DSP 控制器的位置检测接口电路、16 位双极性数模转换器(DAC7641)的扩展电路和控制软件的实现方法。

We are applying to support high quality analog TV measurements and analog/digital TV transmitter and transposer.

为中国用户提供高端的模拟电视测试设备以及模拟、数字电视发射及传输设备。

A high-speed digital-to-analog converter measurement method acquires and quantizes an analog ramp output by the DAC corresponding to a digital ramp input to produce a quantized ramp, determines a start and end of the quantized ramp, obtains a difference between the quantized ramp and an ideal ramp to produce a quantized periodic signal, determines a frequency for a qualified peak from an FFT of the quantized periodic signal, produces a mask filtered periodic signal from an iFFT around the qualified peak, and determines a sample window spanning a local maximum and minimum for each period of the quantized periodic signal.

一种高速模拟数字转换器测量方法，采集和量化由DAC输出的相应于数字斜坡输入的模拟斜坡以产生量化的斜坡，确定量化的斜坡的开始和结束，获得量化的斜坡和理想的斜坡之间的差值以产生量化的周期信号，从量化的周期信号的FFT中确定合格峰值的频率，从合格峰值周围的iFFT中产生屏蔽过滤的周期信号，并且在量化的周期信号的每一周期内确定跨越局部最大值和最小值的采样窗口。

The digital users signals comprising in-phase component and quadrature component are converted to analog baseband signals by digital-to-analog converters 104 and 114, which are followed by lowpass filters 106 and 116 for removing harmonics at unwanted frequencies.

包括同相分量和正交分量的数字用户信号通过数模转换器104和114转换成模拟基带信号，在数模转换器104和114的后面具有低通滤波器106和116，低通滤波器106和116用于去除在不期望频率处的谐波。

In this section we look at the theory behind the techniques used in rotary polishing and the effects that they have on paintwork and the results achieved.

在这里看抛光剂使用背后的理论，到底是怎么一回事，我们如何用好的抛光机和好的使用技巧来达到好的效果。

I'll dig like a psychotic rodent if I have to.

那我就帮你挖到中国去。