查询词典 electric circuit

Circuit principles, analogue circuit, digit circuit which laid me a solid foundation of circuit for the study of communication; the study of electronic circuit of communication provided me with the working principles of analog communication system; the study on communication theory made me grasp the working methods of digital communication; the study on electromagnetic field, electromagnetic wave and aerial let me know that how signals travel through signal paths and how to apply signal and linear system, random signal and system to the research of noise's impact on signals

学习了电路原理、模拟电路、数字电路打下了学习通信的电路基础；学习了通信电子线路掌握了模拟通信系统的工作原理；学习了通信原理掌握了数字通信的工作方法；学习了电磁场与电磁波、微波与天线了解了信号如何在信道中传输；学习了信号与线性系统和随机信号与系统来研究噪声对信号的影响。

And due to the nature of the data acquisition, three data acquisition circuit board are adopted. They are voltage to digit data converting circuit board, current to digit data converting circuit board and digit data input/output circuit board. These circuit boards are used to acquire the main running parameter of the multifunctional experimentation equipment and to control the output of alarm message.The monitor and control program is developed on Delphi5.0 which is an excellent product of Borland Corp.

数据监控系统的硬件以一台工业控制PC机为核心，并根据采集信号的性质配置了电压-数字量转换板、电流-数字量转换板及开关量输入／输出板，对实验台的主要运行参数进行采集并进行报警控制；监控系统的软件以BORLAND公司的Delphi5.0作为开发平台，采用了面向对象的设计方法，运用了多线程、数据库等技术，做到了界面美观、操作方便。

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 Hall probe measurement circuit is mainly composed by the Hall probe, the non-idiostatic offset circuit, the signal amplification circuit, the automatic range conversion circuit and the A/D transducer circuit.

磁场测量装置主要由霍尔探头、不等位电势补偿电路、信号放大电路、量程自动切换电路、A/D转换器组成。

aining at high impedance weak signal measurement,the relations among measuring precision,input impedance and input bias current,the guard technology is applied to design a measuring circuit with guard circuit,adding a guard potential to low-impedance nodes of circuit,the effect of leakage current is reduced.using spice simulation and validates that guard circuit can increase the input impedance of the system and lower the input bias current,the results show that the guard circuit provids a valuable solution for high accuracy measurement of the high impedance weak signal.

摘 要：针对高阻抗微弱信号测量问题，对测量精度与系统输入阻抗、输入偏置电流的关系进行分析，应用保护技术设计了带保护电路的测量电路，将电路中的低阻抗节点加上保护电势，减小漏电流的影响。通过pspice仿真分析，验证保护电路能提高测量系统的输入阻抗和降低输入偏置电流，结果表明保护电路技术能实现对高阻抗微弱信号的高精度测量。

Mainly by the counter circuit, decoding circuit, trigger circuit, display circuit and judder switch circuit and other components.

电路主要由计数器、译码电路、触发电路、显示电路及防抖动开关电路等组成。

For the terminal part, the microwave receival device receives the video signal transmitted by the transmission device and the video signal is displayed on the terminal display. The voice remote circuit includes voice identification circuit, wireless transmission circuit. The voice identification circuit identifies the voice code and the signal is transmitted by wireless transmission circuit to control the action of the robot.

在终端部分，微波接收器件接收发射器件发射的视频信号，在终端显示器上显示出来；声音遥控电路包含声音采集与识别电路，无线发射电路，声音识别电路识别声音指令编码后由无线发射电路发射，控制机器人行动。

After take analyzed deeply for the opened magnet circuit with FEMM (Finite Element Method Magnetics) we find out the field distributing that is separated into three sections . One is the main area what we called as positive field section. Beside the main field there are tow areas that are called the inverted field sections. Loudspeaker arise a very serious distortion when the voice coil moving into inverted field areas. The direction of induced current in the coil part of entered inverted field area is same with the current driving into loudspeaker so that total currents increas largely and heat increase rapidly. With more coils moving into inverted area the voice coil will take on negative inductance properties. It is the main reason that voice coil is burned by heating with increasing current due to arise negative inductance. So opened magnetic circuit is not suitable for the woofers in which the voice coil have wider displacement range. When using this kind magnetic circuit design, the voice coil moving range should be less than the range of positive field to avoid loudspeaker arise serious distortion and heating. Even though voice coil moving range is in the positive area, loudspeaker will still arise more distortion because the field distribution is very cliffy at tow sides of the positive area and full range of magnetic field distribution is not parallel that will arise distortion. Base on above reasons, opened magnetic circuit is not an ideal magnetic circuit for low-frequency loudspeakers. But it can be used in mid-range or high-frequency productions.

开式磁路是由2片钕铁硼磁铁和主导磁板和导磁垫片组成，我们在实践过程中发现这种磁路结构不适合于低频扬声器的使用，我们通过使用FEMM（Finite Element Method Magnetics）软件包对该磁路进行了分析，该磁路的磁场范围被分成3个区域，其中在主导磁板附近形成一个正向磁场，在正向磁场的两边存在反向的磁场，音圈在工作时有很大一部分进入了反向磁场中，在反向磁场内线圈的感应电流方向与驱动电流方向相同，使得音圈呈现出负感抗特性，由于音圈的负感抗特性引起电流的增加导致音圈发热甚至烧毁，因此在扬声器中使用开式磁路时，音圈的运动范围应控制在正向磁场范围之内，否则音圈运动到反向磁场区域时将会产生很大的失真和发热，即使在设计时已经将音圈的运动范围控制在正向磁场范围之内，由于正向磁场的2个边缘磁场强度衰减太快，同时开式磁路中磁场的分布不是平行的，而是自由发散的分布，这样肯定会导致扬声器的非线性失真，因此我们得到的结论是：开式磁路并不是一个理想的磁路，它不适合于低频扬声器的使用，但它还可以应用于中高频扬声器。

The graduation design is based on single chip microcomputer intelligent design of a power source, hardware design is the main task of the circuit design, battery, the three groups of different size power design, system design, manostat ADC0809 adc design, display design, the watchdog circuit module design, 3-8 decoder circuit design, AT89C51 basic circuit design, 74LS161 prescaler design and auxiliary circuit design, Software design task is: initialize program design, and key process design, charge control program design, A/D conversion program design, over-current protection program design, display design program.

本次毕业设计注意是设计一个基于单片机的智能电源，硬件设计的主要任务是：蓄电池充电电路的设计、三组不同大小的电源设计、系统稳压电源设计、ADC0809模数转换电路设计、看门狗电路设计、显示模块设计、3-8译码电路设计、AT89C51基本工作电路设计、74LS161分频器设计和辅助电路设计；软件设计的任务是：初始化程序设计、按键程序设计、充放电控制程序设计、A/D转换程序设计、过流保护程序设计、显示程序设计。

First it analyses all-around design of the electronic computer-based interlocking system and each module then from introducing CAN bus it lucubrates design of the censorial module's software and hardware which is based on CAN bus of signal lamp's stimulant state then the hardware's circuit of the entire system's censorial module is made up of opsonic circuit collecting circuit microcontrolled circuitcircuit of communication interrupt circuit of overcurrenting and reset circuit.

首先对全电子计算机联锁系统的总体设计及各个执行模块进行全面的分析和研究，然后通过介绍 CAN总线技术，着重研究了基于 CAN总线的信号灯模拟状态监测模块的软硬件设计，其中整个系统监测模块的硬件电路主要由硬件调理电路、采集电路、微控制电路、通信电路、高过流中断电路、复位电路等部分组成。

Salt is good, but if the salt becomes flat and tasteless, with what do you season it?

14：33 盐本是好的，盐若失了味，可用什么叫它再咸呢？

He reiterated that the PLA is an army of the people under the leadership of the Communist Party of China.

他重申，人民解放军是在中国共产党领导下的人民军队。