电流

It is thought that the pulse current methods will be used abroad because of their special superiorities.

分析了目前基于热绝缘的多孔硅制备技术发展现状，着重对阶梯电流法和脉冲电流法进行了介绍和比较，认为脉冲电流法因为其特殊的优势，将在以后的发展中得到更广泛的应用。

When short circuit faults occur on one side of a transformer, the sensitivity of current protection on the other side could not be affected.

摘 要：为了避免小电流接地系统中，电流保护的灵敏度受故障类型和相别的影响，提出了一种利用序分量提高电流保护灵敏度的新原理。

The results indicated that good wavelength stabilization could be obtained when a collimating cylindrical lens with diameter of 0.4 mm was used.

研究表明，在相同的工作电流、热汇温度下，当准直柱透镜直径为0.4 mm时的波长稳定效果较好；在此情况下，当热汇温度控制在30 ℃，工作电流从0.5 A增加到1.5 A的测量范围内，以及当工作电流固定在1.5 A，热汇温度从20 ℃增加到35 ℃时，测得的光谱特性表明，半导体激光器的工作波长可以很好地稳定在体布拉格光栅的布拉格波长处。

34C02M8/LM8 Pinout: Short Circuit Current Output Current Transition Time Maximum Transmission Rate 1,000 RS-422 RECEIVER Common Mode Range Differential Input Differential Input Threshold-0.2 Input Voltage Hysteresis30 Input Resistance3 TTL Output Level V V2.4 Maximum Receiving Rate1,000 Short Circuit Output Current POWER REQUIREMENTS V =+12V, 10% V =+5V, 10% V =-12V, 10% ENVIRONMENTAL Operating Temperature -CS0 -MR-55 Storage Temperature-65

34C02M8/LM8引脚说明：短路电流输出电流过渡时期的最大传输速率1000的RS - 422接收器差分输入共模范围差分输入阈值0.2输入电压Hysteresis30输入Resistance3 TTL输出等级V 2.4版本的最大接收Rate1，000短路输出电流电源要求ν= 12五，10％的V =+5 V的，10％的V =- 12V的，10％，环境工作温度- CS0 -议员- 55存储温度- 65

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。

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。

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。

If you change the diode current by changing the resistance value of Rbias, then the transistor's emitter current will follow suit, because the emitter current is described by the same equation as the diode's, and both PN junctions experience the same voltage drop.

正因为发射极和二极管的电流用同一个方程描述，而且两个PN结共用同一个电压，每当你通过改变Rbias改变了晶体管电流，晶体管发射极电流也必将随之同样改变。

The proposed method has fast current response, and can limit the current error and the switching frequency with good current tracking performance.

在降低开关频率条件下，既有较好的电流响应速度，又能有效限制电流误差，改善电流跟踪性能。

The appearance of active power filter provides equipment support for the compensation of harmonic current and reactive current, and the real-time and exaction performance of harmonic current detection in active power

有源滤波器的出现为谐波电流和无功电流的综合补偿提供了设备支持，在有源滤波器中谐波电流检测部分的实时性和精确性至关重要。

I will endeavour to find you some assistance.

我尽力帮你找人帮忙。

At first I only know bruck is the idol of American younglings, afterwards I returned back to Taiwan ,even in Beijing last year ,I saw her poster everywhere, I was so surprised at her charm.

起初我只晓得布鲁克雷德丝是美国少男少女崇拜的偶像，后来回台湾，甚至去年在北京，居然也四处看见她的海报，才惊讶她的魅力之大。