电流放大

The bridge loses balance and sensitive parts have a output signal,which will transform to related current signal after differential magnifying and conversion between current and voltage. Linear 4~20mADC standard signal is formed by compensation of magnifying and non-linear rectified ring circuit ,and second temperature compensation.

输出的电信号，经过差分放大，电压电流转换，变换成相应的电流信号，通过放大和非线性矫正环路的补偿，以及精密的二次温度补偿，产生与输入压力输成线性关系的4~20mADC 二次制标准信号。

Power amplifier part of the larger output current to enhance the amplifier with a load capacity.

功率放大部分放大输出电流，提升放大器的带负载能力。

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。

Issues added: GTO below the opening of the process and shutdown process: Located GTO anode forward voltage electric pressure, when the increase in positive gate trigger current IG, through N1P2N2 transistors amplification makes its collector current IC2 and emitter current IK increase.

问题补充：下面分析GTO的开通过程和关断过程：设GTO阳极电压力正向电压，当在门极加正向触发电流IG后，通过N1P2N2晶体管的放大作用使得其集电极电流IC2和发射极电流IK增加。

The driver stage function obtains enough high voltage amplification factor, as well as the output stage provides enough big drive current, for this reason, may use the belt collection electricity level altogether to shoot the amplifying circuit, its static bias current ratio input level must be big.

推动级的作用是获得足够高的电压放大倍数，以及输出级提供足够大的驱动电流，为此，可采用带集电级的共射放大电路，其静态偏置电流比输入级要大。

The amplifiers chosen must be compensated for unity-gain operation and R6 and R7 must be chosen to minimize output errors due to input offset current.

注释 2：(NE5532 注) R4U i =0 R3 首先，对节点处的电流讨论是没有意义的，流入节点的电流一定等于流出节点的电流，再者，I3 与 I4 不是等大反相的关系，分析如下： 40 An Applications Guide for OP Amps 由于此时 OPA1 处于反相放大状态，其输出电压 U o1 压误差按照设计思路，此时 A2 的输出应该等于 U o1 ，则电流方向如上图。

This paper puts forward the derivation of precise calculating formula used to determine the magnification ratio of voltage, input resistance and output resistance in amplifying circuits based on the feedback circuit model with parallel voltage.

在建立电流并联反馈电路模型的基础上，推导出放大电路中的电压放大倍数、输入电阻、输出电阻的精确计算公式。

It mainly enlarges the digital to tallies chip through Amplifier. It holds the sampling digitalpass to convenience transforming for the chip through sample and hold Circuit, thus it can complete the measurment of current digital y.

主要是通过放大电路将采样到的模拟量放大到和芯片相吻合的数字量，通过采样保持电路将采样的数字量保持住以便后面的芯片进行转换，从而完成电流数字量的测量。

With the current mode logic structure, the input buffer and the predriver circuit have the capability of transmission and amplification of high speed data. By employing MOS-HBT cascode structure as the output stage, the laser diode driver exhibits very high speed and efficiency working at the 10 Gb/s data rate.

输入缓冲、驱动放大电路采用电流模电路，满足高速数据传输和放大的能力，输出级电路结构采用新型的MOS-HBT共源共栅结构可以降低米勒效应减小输入电容，从而使激光驱动芯片工作在10Gb/s时也能达到良好的性能。

At first, this paper gives the brief introduction of the history and present status of accelerometer and its testing technology, the working principium and math model of the liquid floated pendu-lous accelerometer, and then, decides the binary width pulse force retrim loop as the design proposal of testing system, researches the transfer function of every part in the system emphasizly, analyses the stability of the whole accelerometer testing system from the angle of control theoretics by the open loop transfer function of system, and designed the correcting net, analyses the basal problems such as resolution, sampling restraint, precision and so on, designs the hardware testing circuits such as preamplification, band-pass filter, alternating amplifier, phase sensitive demodulatorn, pulse-width modulation, frequency scale circuit, moment current generator. Finally, using the graphics program language LabV-IEW which is designed for testing field especially by NI accomplishes the solfware design of testing system,realized the testing functions.

首先对加速度计及其测试技术的发展历史和现状，液浮摆式加速度计的工作原理和数学模型等作了简要的介绍，然后确定了以二元调宽脉冲再平衡测试回路为设计方案，并从控制理论的角度进行了分析，着重研究了系统中各部分的传递函数，利用系统开环传递函数分析了系统的稳定性，同时设计了系统的校正网络；分析了二元调宽脉冲再平衡测试回路的分辨率、采样约束以及测试精度等基本问题，并按照系统分析的结果设计了包括前置放大、带通滤波、交流放大、相敏解调、脉宽调制、频标电路以及力矩电流发生器等测试系统各部分硬件电路，验证了电路的正确性，最后按照测试系统的要求，采用了美国NI公司专为测试领域所开发的虚拟仪器工具——LabVIEW作为测试软件开发工具，利用该图形化编程语言完成了测试系统软件部分的设计，实现了测试功能。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。