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1.
反馈技术可以大大改善放大电路的工作性能,提高放大电路的稳定性。而在放大电路中普遍采用的是负反馈。所以正确判断负反馈放大电路的组态非常重要。而由于负反馈的概念抽象、复杂,许多学生感到难以理解和掌握。传统的分析判断方法,学习起来非常辛苦,也不容易被学生掌握。我们通过几年的教学实践,发现一种简单易行的方法,现通过本文介绍给大...  相似文献   

2.
负反馈在放大电路中被广泛采用,文章从反馈网络、反馈极性、反馈组态等方面对负反馈电路进行了分析,得出了判断负反馈的方法和技巧,最后以实例说明负反馈电路的应用.  相似文献   

3.
本文通过自动控制原理中的反馈校正法对负反馈放大电路中引入负反馈改善放大器性能的展宽通频带和深度负反馈放大器进行了分析。  相似文献   

4.
放大电路引入负反馈,能有效改善电路性能。本文通过Multisim2001软件,对负反馈放大电路进行了静态和动态的仿真运行,分析输出电压失真的原因,并阐述性能改善的原理。为使电路获得最佳性能,通过对比,分析反馈元件不同参量对反馈性能的影响,验证了在低频线性放大电路中,只有引入合适的反馈量才能使电路获得理想的效果。  相似文献   

5.
1自激振荡产生的原因及危害根据参考资料的讨论可知单级阻容耦合共发射极放大电路在中频区输出与输入的电压相位差是180°。负反馈引入后可以改善放大器的一些性能:如降低放大倍数,提高放大倍数的稳定性,改变输入输出电阻等。但不管情况如何负反馈的反馈信号总是削弱放大器的净输入信号。但是当负反馈的反馈深度D=0时,将会出现反馈放大电路在没有信号输入的情况下会有信号输出,这种现象违背了放大器的输入输出关系,使放大器变为自激振荡。那么负反馈是D>1的,为什么会出现D=0的呢?这是因为单级共射放大器在中频段满足输…  相似文献   

6.
负反馈放大器拆环分析计算基本放大倍数,过程烦琐难以理解。网络分析法将负反馈放大电路按作用进行分解后,各部分均视做双端双口网络进行分析,简单方便易于理解。该方法也可分析级问负反馈和反馈网络含源的负反馈放大器。  相似文献   

7.
采用方框图分析法,对所设计的由运算放大器构成的电压串联负反馈放大电路进行了仿真分析和理论计算.两者结果一致表明:闭环增益与开环增益满足基本关系式;引入负反馈后稳定性得以提高,输出电阻减小;深负反馈条件下,反馈系数的倒数近似等于闭环增益,从而定量地验证了负反馈放大电路中的基本结论.  相似文献   

8.
本文通过对各种形式的负反馈放大电路中反馈类型的分析、比较,总结出一种直观的判断方法。简便实用。  相似文献   

9.
本文首先阐述了负反馈放大电路变换为基本反馈电路的方法,在此基础上总结了利用变换分析法计算负反馈放大电路动态参数(闭环增益、输入电阻、输出电阻)的步骤,并举例讨论了变换分析法在负反馈放大电路分析中的应用.  相似文献   

10.
实际负反馈放大电路,并非都是由基本放大电路和反馈网络构成一个闭环系,还有由多个基本放大电路和多个反馈网络构成的多环系统。给出了几种多环负反馈放大电路的一般方框图和“闭环”增益一般表达式,并浅析。  相似文献   

11.
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.  相似文献   

12.
风的曲线     
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.  相似文献   

13.
Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.  相似文献   

14.
汉字倒说     
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。  相似文献   

15.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

16.
一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/  相似文献   

17.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?  相似文献   

18.
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language.  相似文献   

19.
钱生钱!     
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了  相似文献   

20.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.  相似文献   

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