[电工和电子杂志.2012年.全集].Elektor_Electronics_2012-02
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电气工程专业需阅读的主要经典著作和专业学术期刊目录
需阅读的主要经典著作和专业学术期刊目录一、期刊（1）外文期刊：1. IEEE Transaction on Power Delivery2. IEEE Transaction on Power Systems3. IEEE Transaction on Energy Conversion4. IEEE Power Engineering Review5. IEEE Computer Application in Power6. IEE Proceedings: Part B Electric Power Applications7. IEE Proceedings：Part C Generation, Transmission and Distribution8. Electric Power Systems Research9. International Journal of Electrical Power and Energy Systems10. Electric Machine and Power Systems11. IEEE Transactions on Magnetics12. IEE Proceeding Electric Power Application13. Journal of Magnetism and Magnetic Material14. IEEE Transactions on Industry Application15. IEEE Transactions on Power Electronics16. IEEE Transactions on Applied Superconducting Technology17. IEEE Transactions on Electronic Devices18. Institute of Physics Publishing (IOP)：Measurement Science and Technology(2)中文期刊：1.中国电机工程学报2.电工技术学报3.电力系统自动化4.电网技术5.中国电力6. 电力系统及其自动化学报7．清华大学、西安交通大学、哈尔滨工业大学、浙江大学、华北电力大学、上海交通大学等学报。
电工与电子技术ppt课件
的电位差。
Uab Va Vb
20/105
电压的实际方向规定由电位高处指向电位低处。 与电流方向的处理方法类似， 可任选一方向为电压的参考方向
a
ba
b
+ u1 －
－ u2 +
例： 当ua =3V
ub = 2V时
u1 =1V
u2 =－1V
最后求得的u为正值，说明电压的实际方向
与参考方向一致，否则说明两者相反。
(即在图中表明物理量的参考方向)，然后再列方程 计算。缺少“参考方向”的物理量是无意义的.
(4) 为了避免列方程时出错，习惯上把 I 与 U 的方向
按相同方向假设(关联正方向）。
32/97
例
a
IR b
UR
关联正方向
假设:
I R 与 U R 的方向一致
UR IR R
a
IR b
UR
非关联正方向
假设:
b
Uab
已知：E=2V, R=1Ω
求： 当Uab分别为 3V 和 1V 时，IR=?
解： (1) 假定电路中物理量的正方向如图所示； (2) 列电路方程：
Uab UR E U R Uab E
IR
UR R
Uab E R
30/97
R a
IR E UR
b Uab
IR
Uab E R
43/97
例 已知：US1 = 15V，US2 = 5V，
+ R —I
R = 5Ω，试求电流I 和各 元件的功率。
+
+ US1 UR US2
—
—
解： I US1 US2 15 5 2A
电工与电子技术基础第2版课件第2章
2.2 正弦量的相量图表示法
正弦量除可用三角函数、波形图表示外，但 可用随时间变化的旋转有向线段OA在y轴上的投影 来表示，如图2-4所示。称相量图法 。
y ω u1 t1 to O A ψ x Um u uo O ψ
ωt1
ωt
图2-4 用旋转的有向线段表示正弦量
用有向线段OA的长度表示正弦量的幅值Um(或Im)， OA与x轴正向的夹角表示初相位ψ， OA随时间以逆时 针方向旋转的角速度表示ω，则OA在y轴上的投影为 OA=ASsin(ωt+ψ)。
(1) i 与 u 为 同频 率 ，且 u 超 前 i90° ， 或 i 滞 后 u90°。 (2) Um (U)与Im(I)和ωL符合欧姆定律关系。ωL 的单位是欧姆，具有对i起阻碍的物理性质，称为 电抗，简称感抗，用XL表示，即 XL＝ωL＝2πfL
3.电感元件的功率关系 瞬时功率 p= ui=Imsinωt Umsin(ωt+90˚)=UIsin2ωt 图2-12b中p波形得 ，当p＞0时，电感元件从外界(电 源)吸收电能，并转换为磁场能贮存于线圈中；当p＜0 时，电感元件向外界释放能量，磁场能转换成电能， 并归还给电源。 有功功率P=0。即电感元件在交流电路中无能量 消耗，但电源与电感元件间存在能量的互换。用无功 功率Q来衡量能量互换的规模。规定Q等于瞬时功率p 的幅值，即 2 U Q＝UI＝I2XL＝ X L Q单位用乏 [尔] (Var)
在交流电路中，因各电流和电压多 +j A 为同一频率的正弦量，故可用有向线段 b r 来表示正弦量的最大值 ( 有效值 ) Im 、 ψ Um(I、U)和初相ψ ，称为正弦量的相量。 O a +1 在正弦量的大写字母上打“ •”表示，如 图2-5 有向线段的表示正弦量 幅值电流、电压相量用 I m、 U m表示，有 • U 效值电流、电压相量用 I 、 U 表示。将电 • 路中各电压、电流的相量画在同一坐标 φ I ψ 中，这样的图形称为相量图。 ψ 同频率的u和i可用图2-6相量图表示。 图2-6 u和i的相量图 即 U 超前 I φ°，I 或 U 滞后φ°。
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电工电子技术及应用全套课件
7、 欧姆定律
U、I 参考方向相同时， U、I 参考方向相反时，
+
U = RI
+
U = – RI
U IR
U
–
–
表达式中有两套正负号：
IR
① 式前的正负号由U、I 参考方向的关系确定；
② U、I 值本身的正负则说明实际方向与参考
方向之间的关系。
通常取 U、I 参考方向相同。
例：应用欧姆定律对下图电路列出式子，并求电阻R。
3）电流的实际方向
正电荷运动的方向。(客观存在）
电流的方向可用箭头表示,
也可用字母顺序表示( iab )
iab R
a
b
4、 电压
1）电位
定义：电场力把单位正电荷从一点移到参考点所做
的功。
（电路中电位参考点：接地点，Vo= 0） 单位： V（伏特）、kV（千伏）、mV(毫伏）
二、电压
定义： 电场力把单位正电荷 从一点移到另一点所 做的功。
+
UI 6V 2A
R
– (a)
+
U 6V
I R
– –2A
(b)
解：对图(a)有, U = RI 所以: R U 6 3Ω I2
对图(b)有, U = – RI 所以: R U 6 3Ω I 2
线性电阻的概念：
遵循欧姆定律的电阻称为线性电阻，它表示该段 电路电压与电流的比值为常数。
即：R U 常数 I
U、I 参考方向相同，P =UI 0，负载；
P = UI 0，电源。
U、I 参考方向不同，P = UI 0，电源； P = UI 0，负载。
电气设备的额定值
额定值: 电气设备在正常运行时的规定使用值 1. 额定值反映电气设备的使用安全性；
电工与电子技术[毕淑娥][电子教案]第13章
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输入
或非逻辑运算真值表
输出
A 0 0 1 1
B 0 1 0 1
Y 1 0 0 0
A B
(a)
≥1
Y
A B
Y
(b) 国际标准符号 或非门逻辑符号
图13.2 10
国际常用符号
或非逻辑真值表
或非门逻辑符号
有“1”出“0” 全“0”出“1”
13.2 逻辑运算及其门电路
四2输入与非门74LS00的外形图及管脚图
A YA
非逻辑运算真值
1
A
Y
1
Y A
A
Y
+5V
Y
表13.2-5 表
非门逻辑符号 (b) 国际常用 ( a ) 国际标准符号 (b) 国际常用符号 (a ) 国际标准符号
+5V
输入 A 0 1
输出 Y 1 0
A
RC RB
T
图13.2 5 非门逻辑符号
Y
A
R4 图 13 .2 5R 非门逻辑符号 2 R 1 T3 D2 T4 R3 T1 D1 T2
Y
非逻辑真值表
图13.2 6 三极管非门电路 三极管非门电路
集成 非门的内部电路 (bTTL ) 内部原理电路
13.2 逻辑运算及其门电路
六反相器（非门）74LS04的外形图及管脚图
13.2 逻辑运算及其门电路
13.2.2 复杂逻辑运算及其门电路
由上面的三种基本运算可以组合成与非运算、或非运算、 与或非运算、异或运算和同或运算。 1. 与非运算及其与非门 两输入逻辑变量的与非运算逻辑式为
13.2 逻辑运算及其门电路
3. 与或非运算及其与或非门 与或非运算的逻辑式为
或非逻辑运算真值表
输出
A 0 0 1 1
B 0 1 0 1
Y 1 0 0 0
A B
(a)
≥1
Y
A B
Y
(b) 国际标准符号 或非门逻辑符号
图13.2 10
国际常用符号
或非逻辑真值表
或非门逻辑符号
有“1”出“0” 全“0”出“1”
13.2 逻辑运算及其门电路
四2输入与非门74LS00的外形图及管脚图
A YA
非逻辑运算真值
1
A
Y
1
Y A
A
Y
+5V
Y
表13.2-5 表
非门逻辑符号 (b) 国际常用 ( a ) 国际标准符号 (b) 国际常用符号 (a ) 国际标准符号
+5V
输入 A 0 1
输出 Y 1 0
A
RC RB
T
图13.2 5 非门逻辑符号
Y
A
R4 图 13 .2 5R 非门逻辑符号 2 R 1 T3 D2 T4 R3 T1 D1 T2
Y
非逻辑真值表
图13.2 6 三极管非门电路 三极管非门电路
集成 非门的内部电路 (bTTL ) 内部原理电路
13.2 逻辑运算及其门电路
六反相器（非门）74LS04的外形图及管脚图
13.2 逻辑运算及其门电路
13.2.2 复杂逻辑运算及其门电路
由上面的三种基本运算可以组合成与非运算、或非运算、 与或非运算、异或运算和同或运算。 1. 与非运算及其与非门 两输入逻辑变量的与非运算逻辑式为
13.2 逻辑运算及其门电路
3. 与或非运算及其与或非门 与或非运算的逻辑式为
电工与电子技术(毕淑娥主编)第8章.
基座 定子绕组
8.2 三相异步电动机
2．转子 三相异步电动机转动部分，包括转子铁心、转子绕组、转 轴、风扇等，有笼型和绕线型两种 。
绕线式转子
实物图 鼠笼式转子
转子结构示意图
滑环
8.2 三相异步电动机
8.2.2 三相异步电动机的工作原理
1．定子的旋转磁场
(1)旋转磁场的产生
8.2 三相异步电动机
8.1 直流电动机
【例8.1-1】他励电动机，已知额定电枢电压UN = 110V，额定电 枢电流IaN = 50A，电枢电阻Ra = 0.12W。问：(1)如果直接启动， 计算电枢的启动电流Iast，它是IaN的多少倍？(2)如果要求Iast不超 过IaN的两倍，启动电阻Rst应为多少？
【解】(1)直接启动时的Iast
(1)由公式T=KT ΦIa可知，调速 【解】
后负载转矩TL不变，即电动机转矩T不 变，Φ 不变，故电枢电流Ia也不变。
(2)根据转速公式计算其中的电压U:
U N I aN Ra E nN K E K E
220 60 0.5 = 1500 r / min K E U I a Ra U 60 0.5 n = 1350 r / min 19 K E 150
最大转矩
sR2U12 T=K 2 R2 + ( sX 20 ) 2
启动转矩 转矩曲线 额定转矩
8.2 三相异步电动机
2．三相异步电动机的机械特性曲线n= f (T ) 机械特性是在U1、R2和X20为定值的条件下，电动机的转 速n与电磁转矩T的关系，即n = f (T )，利用它可以分析电动机 的运行性能和运行状态。
8.1 直流电动机
【例8.1-1】他励电动机电路如图所示。其额定励磁电压UfN = 220 V，额定电枢电压UN = 220V，额定电枢电流IaN = 60A，电枢电阻 Ra = 0.5W，额定转速nN = 1500r/min。现采用调压的方法将电动 机转速调至n = 1350r/min，电枢电压U应调至多少？设调速后负 载转矩TL不变。
电工电子技术第三章课件
3.3 RC电路的响应 ☆ ☆（1学时）
3.4 一阶线性电路暂态响应分析的三要素法 ☆☆☆☆（1学时） 3.5 微分电路与积分电路（0.5学时）
3.6 RL电路的响应 ☆ ☆（0.5学时）
电工与电子技术 I
Electrotechnics & Electronics
§3-1 电阻元件、电感元件与电容元件
§3-1 电阻元件、电感元件与电容元件
二、电感元件
i
+ i u
+ u _
L
电感元件 ——
实际线圈的理想化模型，假想由无阻导线绕制而成
电工与电子技术 I
Electrotechnics & Electronics
§3-1 电阻元件、电感元件与电容元件 i + i + u u _ L
电感(Inductance) —— L ？ 楞次(Lenz)定律——当变化的磁通穿过线圈时，线圈中 的感应电动势趋于产生一个电流，该电流的方向趋于阻 碍产生此感应电动势的磁通的变化。
di eL L dt
电工与电子技术 I
Electrotechnics & Electronics
§3-1 电阻元件、电感元件与电容元件
u与 i 的关系？
ψ
i +
eL
+
u
_ i
u eL 0
+ u
eL
+
L
di u eL L dt
电工与电子技术 I
Electrotechnics & Electronics
介质的介电常数 两极板间距离 极板面积
（ 米2 ）
电工与电子技术 I
电工与电子技术(第3版) 第1章 电路的基本概念与基本定律
+
U
U、I 参考方向相反时
U=IR
I
R
+
U
U = – IR
I
R
–
–
表达式中有两套正负号：
(1) 式前的正负号由U、I 参考方向的关系确定。
(2) U、I 值本身的正负则说明实际方向与参考方向
之间的关系。
通常取 U、I 参考方向相同。
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电工与电子技术
线性电阻的概念：
遵循欧姆定律的电阻称为线性电阻，它表示该段
（共6条）
c 节点：a、 b、c、d
(共4个）
回路：abda、abca、 adbca …
（共7 个）
网孔：abd、 abc、bcd
（共3 个）
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电工与电子技术
1.5 基尔霍夫定律
1.5.1 基尔霍夫电流定律（KCL）
对于电路中的任一节点，任一瞬时流入或流出
对于电路中的任一节点，任一瞬时流入该节
= − = −(−) × =
= = × =
U1
R1
R2
U2
E2
E1
= = × =
< ， > ， > ， > ，
所以 为电源，其它均为负载。
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电工与电子技术
门铃印刷电路板
电路图
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电工与电子技术
1.1 电路作用与电路模型
电路是电流的通路;是为实现某种预期目的由电源
和电气电子元部件通过导线连接而成。
1. 电路的作用与组成
(1) 实现电能的传输、分配与转换
[电工和电子杂志].Elektor-Electronics.Uk.2011-11
20 Improved Radiation Meter
Gamma, beta and alpha radiation levels get measured with this instrument based on a cheap and cheerful PIN photodiode.
26 Simple Bat Detector
This circuit monitors the voltage output of a solar cell while consuming preciously little power itself.
44 E-Labs Inside: Working with Stencils
A step by step guide to making perfect SMD boards as far as applying solder paste is concerned.
4
CONTENTS
16 Super Arduino
The chipKIT TM Max32 board offers 32-bit computing power and some 80 I/O pins while remaining compatible with the Arduino environment. It is the hardware component of the exciting design challenge brought to you by RS Components, Circuit Cellar and Elektor. In this article you’ll find a number of tips that should give you a head start in working with the hardware and software that go into making your entry for the challenge.
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A review of the latest sub £400 mixed signal oscilloscope from Pico Technology.
38 Eclipse Sensor
This instrument was specifically developed to measure sky brightness during a (partial) solar eclipse.
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[Microcontrollers & Embedded • Analogue • Audio• Digital • Test & Measurement]
February 2012 AUS$ 14.90 - NZ$ 17.90 - SAR 105.95 - NOK 102 £ 4.90
A Serial Interface for Android Smartphones and Tablets
™
Have you entered the DesignSpark chipKIT™ Challenge yet? Visit today to join the fun! When you submit a proposal for an energy-efficient design, your project will automatically be considered for a chipKIT™ Community Choice Award.* In February, participants of the chipKIT™ Challenge will have the opportunity to vote on what project they think is the best. If your project receives the most votes, you will win a $100 voucher for RS Components/Allied Electronics and a free digital subscription to Circuit Cellar and Elektor magazines! Register your project at to participate.
13
From Breadboard to PCB
From now on, Elektor PCB Service is the one-stop shop for printed circuit boards
14
AndroPod (1)
This Elektor-developed board adds TTL and RS485 connectivity to your Android smartphone or tablet.
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Personal Download for I © Elektor
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All things considered but measured first
6
It’s been noted frequently that electronic circuits are getting increasingly complex in design and have a bad tendency to attract microprocessors for no apparent reason. It seems logical because micros enable the amount of hardware to be reduced drastically while still offering flexibility in terms of functionality of the circuit — in other words, you just program in what you think you might need. No soldering, no parts purchasing. Great, electronics gone all digital! Just deal with ones and zeroes, no problems with analogue signals that vary in level just by pointing at a PCB track. Tough luck. Any digital circuit that somehow needs to communicate with the outside world, is again using analogue signals. It’s because our real world simply isn’t digital — in between all kinds of extremes like ‘on’ and ‘off’, ‘all’ and ‘nothing’, ‘hot’ and ‘cold’, ’dark’ and ‘light’, there’s a whole range of gradations (well, with a few exceptions). So what does a digital circuit do to communicate with the real world? The analogue value measured by a sensor is first translated into a digital value (by an A/D converter) before it can be processed by digital electronics. Likewise, at the output of the circuit it is often necessary to convert digital back to analogue, usually with the help of a D/A converter or a PWM control. These considerations were spurred by the very contents of this February 2012 edition, which contains several projects that seem to happily combine the analogue and digital realms. Fine examples are the new software for the enhanced Pico C meter, the interface for wideband lambda probe, and the dynamics processor discussed in the Audio DSP Course. The above ADC-digital-DAC method applies to all of these, and more. Never disregard the analogue bits in your digital circuit — although not MSB, they’re still highly significant. Enjoy reading this edition, Jan Buiting, Managing Editor
AndroPOD
+ unravelled and applied to a keyless entry control panel
Bit-banging the FTDI-USB Module
Pico C-Plus & Pico C-Super
Our ‘small-C’ meter upgraded in two ways
22 Pico C-Plus and Pico C-Super
New software has been developed for the Elektor Pico C meter, giving it a vastly extended capacitance range as well as some extra features like a frequency meter.
43 E-Labs Inside: leading doweditors won a soldering contest by accident.
44 The many faces of Elektor
A photo impression of activities and visitors at the Elektor Live! 2011 event.
4
Colophon
Who’s who at Elektor.
8
News & New Products
A monthly roundup of all the latest in electronics land.
12
DesignSpark chipKIT™ Design Challenge
A global electronics design competition brought to you by Circuit Cellar, Elektor and RS Components.
28 .Net-MF for Electronics Engineers
Microsoft’s new platform for 16-, 3-2 and 64-bit system is off to a promising start, mostly due to a number of FEZ modules. We looked at four of these.
Visit
for complete rules and details.
38 Eclipse Sensor
This instrument was specifically developed to measure sky brightness during a (partial) solar eclipse.
52429
[Microcontrollers & Embedded • Analogue • Audio• Digital • Test & Measurement]
February 2012 AUS$ 14.90 - NZ$ 17.90 - SAR 105.95 - NOK 102 £ 4.90
A Serial Interface for Android Smartphones and Tablets
™
Have you entered the DesignSpark chipKIT™ Challenge yet? Visit today to join the fun! When you submit a proposal for an energy-efficient design, your project will automatically be considered for a chipKIT™ Community Choice Award.* In February, participants of the chipKIT™ Challenge will have the opportunity to vote on what project they think is the best. If your project receives the most votes, you will win a $100 voucher for RS Components/Allied Electronics and a free digital subscription to Circuit Cellar and Elektor magazines! Register your project at to participate.
13
From Breadboard to PCB
From now on, Elektor PCB Service is the one-stop shop for printed circuit boards
14
AndroPod (1)
This Elektor-developed board adds TTL and RS485 connectivity to your Android smartphone or tablet.
52429
Personal Download for I © Elektor
52429
All things considered but measured first
6
It’s been noted frequently that electronic circuits are getting increasingly complex in design and have a bad tendency to attract microprocessors for no apparent reason. It seems logical because micros enable the amount of hardware to be reduced drastically while still offering flexibility in terms of functionality of the circuit — in other words, you just program in what you think you might need. No soldering, no parts purchasing. Great, electronics gone all digital! Just deal with ones and zeroes, no problems with analogue signals that vary in level just by pointing at a PCB track. Tough luck. Any digital circuit that somehow needs to communicate with the outside world, is again using analogue signals. It’s because our real world simply isn’t digital — in between all kinds of extremes like ‘on’ and ‘off’, ‘all’ and ‘nothing’, ‘hot’ and ‘cold’, ’dark’ and ‘light’, there’s a whole range of gradations (well, with a few exceptions). So what does a digital circuit do to communicate with the real world? The analogue value measured by a sensor is first translated into a digital value (by an A/D converter) before it can be processed by digital electronics. Likewise, at the output of the circuit it is often necessary to convert digital back to analogue, usually with the help of a D/A converter or a PWM control. These considerations were spurred by the very contents of this February 2012 edition, which contains several projects that seem to happily combine the analogue and digital realms. Fine examples are the new software for the enhanced Pico C meter, the interface for wideband lambda probe, and the dynamics processor discussed in the Audio DSP Course. The above ADC-digital-DAC method applies to all of these, and more. Never disregard the analogue bits in your digital circuit — although not MSB, they’re still highly significant. Enjoy reading this edition, Jan Buiting, Managing Editor
AndroPOD
+ unravelled and applied to a keyless entry control panel
Bit-banging the FTDI-USB Module
Pico C-Plus & Pico C-Super
Our ‘small-C’ meter upgraded in two ways
22 Pico C-Plus and Pico C-Super
New software has been developed for the Elektor Pico C meter, giving it a vastly extended capacitance range as well as some extra features like a frequency meter.
43 E-Labs Inside: leading doweditors won a soldering contest by accident.
44 The many faces of Elektor
A photo impression of activities and visitors at the Elektor Live! 2011 event.
4
Colophon
Who’s who at Elektor.
8
News & New Products
A monthly roundup of all the latest in electronics land.
12
DesignSpark chipKIT™ Design Challenge
A global electronics design competition brought to you by Circuit Cellar, Elektor and RS Components.
28 .Net-MF for Electronics Engineers
Microsoft’s new platform for 16-, 3-2 and 64-bit system is off to a promising start, mostly due to a number of FEZ modules. We looked at four of these.
Visit
for complete rules and details.