EMC电磁兼容原理

EMC - a definition
EMC means nothing more than "an electronic or electrical product shall work as intended in its environment. The electronic or electrical product shall not generate electromagnetic disturbances, which may influence other products". In other words, EMC deals with problems of noise emission as well as noise immunity of electronic and electrical products and systems. Electromagnetic disturbances occur as conducted interference as well as radiated emissions and immunity problems.
Generally EMC, Electro Magnetic Compatibility, should really not be difficult to understand, but as you know, the devil is in the details. Let us explain the topic in a little bit more details. For those of you who are EMC-experts, we hope you excuse us for making some "non-scientific" simplifications. 
The word EMC does not include the influence of electromagnetic waves (either desired or undesired) on biological systems. This is a much larger field and is covered by the expression "EMCE" ("E" is for environmental), which is not the topic here and is also not the field in which EM TEST works.

Where EMC got started
The history of EMC
Let us go back in the history of EMC. EMC is older than you may believe.
We are all living with our history. The same is for EMC. You may not know, as many EMC experts also do not know, how everything was started. We want to give you a short summary of the history of EMC in Europe. The following is not given in great detail, but it does illustrate why we are where we are today in the EMC world.

The new age of communication in Europe began 1892 when the German Parliament voted to create the "Law of egraph in the German Empire". This was the first law in the world that dealt with influences of electromagnetic disturbances on products and installations in the field of egraph technique. This law also regulated the procedures to be followed in case such electromagnetic disturbances were found. People at that time had discovered very quickly that cables did disturb each other. The disturbances on egraph and ephone communication were the most severe. The German Society of Electrotechnicians, founded in 1893, was the foundation of what today is well known as VDE. Wilhelm von Siemens was one of the original founders of this famous society.

More than 110 years ago EMC was not a big matter but this was changed immediay in the evening of December 22 in 1920. On this night, the radio station of König Wusterhausen southeast of Berlin broadcasted the Christmas concert of the German mail officials. The concert was a live event and the audience included the German Chancellor Hermann Müller, who was close to the concert location in the famous castle of König Wusterhausen. The Chancellor was not very amused by the electrical noise interference generated by vehicles passing by and he gave strict orders to immediay prevent such disturbances. The hour of "Radiated Emission" had come and was then later on called EMC.

EMC standardization in the past
The first steps towards standardization ...
Germany was among the first to recognize the need to prevent and solve the problems of radiated emissions. In 1933, the international committee for radiated emissions, better known as CISPR was founded. Late in the 60's, concrete investigations were made to deal with the immunity of electrical products. In 1973 the International Electrotechnical Commission, the IEC, founded the technical committee TC77 whose function is to develop standards related to EMC.

In the 2nd World War knowledge of electromagnetic waves and their ability to create disturbances was used. During the war, radar technology was developed. Not only did the new communication technologies of radio, evision and ephone require electromagnetic compatibility, they were the driving force in changing from tube technology to transistors. The evolution of highly integrated chip technologies requires a broad understanding and use of EMC design experience.

As the technology progressed, legislation and standardization was developed to insure the harmony of the new sciences from an EMC standpoint.

Lets go back again to the German example. In 1927 the first edition of the "Deutsche Hochfrequenzgerätegesetz" was published. The recommendations of Chancellor Müller were successfully introduced although it took about 7 years to result in an official law. The new law was revised several times and was matched to the technical progress. This law was valid until December 31 of 1995 and was then replaced by the German EMC law, which is based on the European Directive.

Every product's reliability depends on EMC
No electrical product or installation can be designed seriously unless all aspects of EMC are taken into account. This is not only important for common products such as radios, evision sets, computers, ephones, washing machines, etc., but it is also especially important for complex products such as vehicles, aircraft, ships and large industrial installations. These are very sensitive to EMC problems and no one wants to accept serious disturbances within a big chemical plant.

Because of all the efforts made and being made to insure EMC compatibility, people start to believe that, after a certain time, all products are safe and immune. Sorry, but this has not come true as yet. Each new generation of engineers and technicians are again challenged by the issue of EMC with each new product and within each new installation. Practical solutions to EMC problems are not taught at universities. This can only be achieved with many years of experience in the field and testing. This is where EM Test can be of help.

EM Test has the task of educating engineers and technicians about EMC. EM Test can use its EMC experience to help all. Remember how this very interesting technical field began and developed. Only those who know the sources, and our sources are the basics of EMC, know where he has to go. We know the issues from the very beginning and will support you so that you better understand them. Let's go together a part of this way and let's keep in contact. By reading this message you have completed the first step.
电磁兼容性-定义
EMC指的只是“电子产品或电子产品在其环境中的工作原理”。电子或电气产品不应产生电磁干扰，可能影响其他产品。换句话说，EMC涉及电子电气产品和系统的噪声发射和抗噪声问题。电磁干扰主要表现为传导干扰和辐射发射和免疫问题。
一般来说电磁兼容，电磁兼容性，真的不难理解，但你知道，魔鬼是在细节。让我们更详细地解释一下这个话题。对于你们这些EMC专家来说，我们希望你们原谅我们进行一些“非科学”的简化。
EMC这个词不包括电磁波（无论是期望的还是不希望的）对生物系统的影响。这是一个更大的领域，由“东蒙大拿教育学院”（“E”是环境），这不是今天的主题，也不在EM测试工作的领域。

EMC在哪里开始的
电磁兼容的历史
让我们回到EMC的历史。电磁兼容比你想象的要老。
我们都生活在我们的历史中。EMC也是如此。你可能不知道，很多EMC专家也不知道，一切都是怎么开始的。我们想给你简要介绍一下欧洲电磁兼容的历史。下面的内容并不是非常详细的，但它确实说明了我们今天在EMC世界中的地位。

欧洲的新通讯时代开始于1892年，当时德国议会投票决定建立德意志帝国的《电报法》。这是世界上*条处理电报技术领域中电磁干扰对产品和装置影响的法律。该法还规定了在发现电磁干扰的情况下应遵循的程序。当时的人们很快就发现电缆确实互相干扰。电报和通信的干扰zui为严重。对电工的德国社会，成立于1893，是*的VDE是什么今天的基础。Wilhelm von Siemens是这个社会的创始人之一。

110多年前EMC并不是一件大事，但在1920 12月22日的晚上，这种情况立即改变了。在这个晚上，KöNIG Wusterhausen东南柏林电台播出的德国邮政官员的圣诞音乐会。这场音乐会是一个生活事件和观众包括德国总理Hermann Müller，谁是接近演唱会地点在的KöNIG武斯特豪森城堡。校长对过路车辆产生的电噪音干扰不甚感兴趣，他下令立即阻止这种干扰。“辐射发射”的时间已经到来，后来称为电磁兼容。

电磁兼容标准化
走向标准化的*步…
德国是zui先认识到需要防止和解决辐射排放问题的国家之一。1933、辐射委员会，更好地称为CISPR成立。60年底，就电气产品的豁免问题进行了具体调查。1973电工委员会，IEC，成立了技术委员会TC77其职能是制定相关的电磁兼容标准。

在第二次世界大战中，电磁波的知识和它们制造干扰的能力被使用了。战争期间，雷达技术得到发展。无线、电视、等新的通信技术不仅要求电磁兼容，而且是从管技术向晶体管转换的驱动力。高度集成的芯片技术的发展需要广泛理解和使用EMC设计经验。

随着技术的进步，立法和标准化的发展，以确保和谐的新科学，从EMC的立场。

让我们再回到德国的例子中。1927的*个版本的“德意志hochfrequenzgerätegesetz”出版。校长ü建议M ller成功引进了虽然大约花了7年的结果在一个正式的法律。新法律修订了几次，与技术进步相匹配。该法有效期至1995 12月31日，其后由德国EMC法取代，该法以欧洲指令为基础。

每个产品的可靠性取决于EMC。
除非考虑到EMC的所有方面，否则不能认真设计电气产品或安装。这不仅对收音机、电视机、计算机、、洗衣机等常见产品很重要，而且对诸如汽车、飞机、轮船和大型工业装置等复杂产品也特别重要。这些对EMC问题非常敏感，没有人愿意接受大型化工厂的严重干扰。

由于所有的努力和确保EMC兼容性的努力，人们开始相信，经过一定时间，所有产品都是安全和免疫的。对不起，这还没有实现。每一代的工程师和技术人员都再次受到电磁兼容问题的困扰。大学不教授电磁兼容问题的实际解决方案。这只能通过多年的实地经验和测试来实现。这是EM测试可以帮助的地方。

电磁测试对工程技术人员进行电磁兼容教育。EM测试可以利用它的EMC经验来帮助所有人。记住这个非常有趣的技术领域是如何开始和发展起来的。只有那些知道来源和我们的来源是EMC的基础，知道他必须去哪里。我们从一开始就知道问题，并会支持你，以便你更好地理解它们。让我们一起走这条路的一部分，让我们保持。通过阅读这条信息，你已经完成了*步。