原理

This text introduce a sort of new pattern soft switch PFC circuit .First, analyze the develop course of the on-off power supply. Second, relate the harm of humorous wave to the commonality electricity net. Third, present the topology and the principium chart of the soft switch PFC and analyze it .At last ,set the parameter and simulates the converter of with matlab simulation. more over ,get the hold of well voltage and current wave , minish the spoilage of the circuit, enhance the efficience of the circuit, meet the demand of the miniaturization and viridity.

本文引入了一种新型的软开关PFC电路，首先分析了开关电源的发展历程，然后讲了谐波给公共电网造成的危害，再给出了这种软开关PFC的电路拓扑及原理图并对其工作原理进行了分析，最后对其参数进行设置在MATLAB软件进行了仿真，并得到了良好的电压电流波形，而且减小了电路的损耗，提高了电路的效率，实现了小型化，绿色化的要求。

It contained system principle block diagram, exposition to the main part, circuit and software flow chart. The test of volt-ampere characteristic to sample tester were provided. It is easy to find that this tester has very good performance according to the test result and it is a more practical.

详细地给出了该测试仪的系统实现原理框图，并对其中的主要部分进行了详细地阐述，给出了相应部分的电路原理图，以及软件实现流程图，并通过对所设计的样机进行了伏安特性的测试，根据测试结果可以看出，该测试仪具有很好的性能，是一个比较实用的测试仪器。

At first, the DC and AC characteristics of the HBT were studied theoretically. Then a voltage comparator was designed.

首先，分析了HBT的基本工作原理；然后比较详细地分析了ECL电压比较器的工作原理并进行了设计。

The principle and design method of a new high-freuency induction water-heater, using half- bridge parallel resonant inverter are introduced.

介绍了一种利用半桥谐振电路实现的新型电磁热水器的设计原理和方法试验结果表明基于感应加热原理的电磁热水器可稳定工作在1.5kW，30kllz的范围，并使输入谐波降到最低，负载侧功率因数达96%以上，效率达92

Is studied, the large deviation principle in the weak topology σ(L~1,L~∞) and the weak*-LDP in the strong L~1-topology for f_n~* are established.

h_n=0，nh_n~d=+∞本文的第一部分研究独立同分布情形，我们得到了f_n~*在弱拓扑下的大偏差原理以及在L~1-拓扑下的弱*大偏差原理。

Static VAR Compensator is the effective solution to improve the Voltage adjustment level and the electrified wire netting steady state.

本论文主要分析各种类型 SVC的结构与原理、各自的特性和对电压控制的原理，以及SVC并联补偿的作用。

Design a complete set of stage lighting control system for the hardware and paint a complete circuit diagram of principle, schematics and wiring diagram.

设计一套完整的舞台灯光控制系统的的硬件电路并画出完整的原理框图、原理图及接线图。

Then various synchronous modules are wrapt by synchronous-asynchronous conversion interface, and each module communicates asynchronously.

本文从异步电路设计原理及GALS系统原理、方法和模块设计等方面展开了广泛的研究，为GALS设计奠定了基础。

But you have to realize that there are man-to-man principles in zone defense, and there are zone principles in man-to-man defense.

但是你必须懂得在区域防守中有人盯人的防守原理，在人盯人的防守中也存在区域防守原理。

The Schematic diagram of the aberrometer and the flow charts of program are illustrated.

本文详细介绍了一种新型主观式波前像差仪的工作原理，具体地阐述了主观式波前像差仪的光路控制系统、瞳孔自动跟踪系统以及计算机软件控制系统，并给出了像差仪的结构原理图以及程序控制流程图。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐