电路

Said invented method for and device adopt MCU or logic or logic chip detecting said ringing current signal, backboard ringing current signal and mutual sent signal, and sequential control sequential control, avoiding switch device hard switching and arcking, raising switch device and backboard reliability.

本发明方法及装置通过采用MCU或逻辑芯片检测本板铃流信号，背板铃流信号和互送信号，并采用时序控制，避免了在铃流开机和切换时的开关器件硬切换，以及铃流的在开关电路切换时的拉弧，提高了开关器件的可靠性；而且把开关电路从通讯设备插框背板转移到单板上来，提高了背板的可靠性，降低了后续的维护和检修困难。

The discussion covers: 1、By theoretical analysis on the measurement circuit of the piezoelectric accelerometer, a optimization design for charge amplifier is proposed which uses TL081 to replace a largenumber of discrete components. The design not only improve the integration of the circuit, but also have some extra merits, including smaller volume, lower consumption, less autoeciousness and stronger resistance to interruption. 2、Affiliated conditional circuit and filter to the devised charge amplifier, the signal is normalized and the noise ( generally, high frequency signal and DC signal) are restrained.

论文完成的主要工作如下： 1、通过对压电加速度传感器测量电路的理论研究，提出用TL081芯片取代大量的分离元件进行电荷放大器的优化设计方案，从而提高了电路的集成度，使其具有体积小、功耗低、寄生因素少和抗干扰性能强的优点。

In this method, the sine, cosine signal is converted by three line autosyn and its output is a binary code based on AD2S83. The measurement datum can be read and displayed by computer.

着重研究了自整角机的三相信号通过隔离转换电路转换成正、余弦信号，输入到高精度AD2S83的轴角／数字转换电路转换成二进制数字信号，供给计算机系统读数显示。

Bachel degree above, majing in Electronics, with over 2 years related wk experience; over 1 year wk experience in EMC design of board /card products; familiar with EMC testing stards the technical requirements of EMC EMS testing items; familiar with theetical knowledge in analog circuit, digital circuit, high-frequency electronic circuit, signal system electromagnetic field.

电子类专业本科以上学历，2年以上相关工作经验，有1年以上板卡类产品EMC设计工作经验，了解EMC测试标准，熟悉EMC，EMS的各项测试项目的技术要求，熟悉模拟电路，数字电路，高频电子线路，信号与系统，电磁场的理论知识。

At system level design, we select the feed-forward form to be benefic for stability and linearity design.

在电路设计方面，大的负载电容、高的时钟频率和高的线性度要求是电路设计的难点。

With PWM control chip L4981A, the bridgeless AC/DC topologic circuit is constructed. Its principal is analyzed and simulated with PSpice, its design process is introduced,and the experimental result is shown.

通过高功率因数PWM控制芯片L4981A，构建桥式AC/DC拓扑电路，分析了其工作原理并进行了系统仿真，叙述了拓扑电路的设计和参数选取过程，最后给出了样机实验结果。

The resonant phenomenon of Bridgeless Boost PFC with split inductor s is analyzed using experiments, simulation and equivalent circuit methods.

通过实验、仿真和等效电路模型分析方法对分立电感无桥Boost PFC电路电感电流上叠加有高频谐振电流的现象做出了详细的分析和研究，指出高频谐振是PFC分立电感与电路的寄生电容组成LC振荡回路所引起的，确定了谐振电流的路径和谐振频率的大小。

Based on bridgeless PFC topology,a 1 500 W prototype has been designed.The control chips use L4981 and IR1150 based on average current control and one-cycle control technology.

实验基于无桥Boost PFC拓扑，控制电路分别采用&平均电流控制&技术的芯片L4981和&单周期控制&技术的芯片IR1150，研制出一台1500W的实验样机，并对两种控制电路进行了详细的对比分析。

For carrying out a small physical volume and high reliability of the motor driving and control,by using HIP4081 chip and ALN hybrid integrated technology,a hybrid integrated technology H bridge circuit based on HIP4081 is designed to control bidirectional circumrotation and speed regulation of the motor.

摘 要：为了实现小体积、高可靠的电机驱动与控制，利用HIP4081专用芯片和ALN厚膜混合集成技术，设计一种基于HIP4081的厚膜H桥电机驱动电路，完成了H桥式驱动电路对电机双向转动和调速的控制。

By practical application,the bidirectional circumrotation/speed adjustment of motor are realized safely and reliably.The products has a small physical volume,fast heat transmission,high efficiency and can operate properly in severe environment.It can enhance the reliability of the drive circuit and the system,and adapt to both military and commercial usage.

经实际应用，该电路不仅安全可靠地实现了电机的双向转动和调速功能，且产品体积小，导热性能好，效率高；还能在恶劣的使用环境下安全工作，提高了驱动电路和系统的可靠性，适合军、民两用。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了