EE281-Electric Circuits

class: center, middle

# EE-281 ELECTRIC CIRCUITS

## Ozan Keysan

[ozan.keysan.me](http://ozan.keysan.me)

Office: C-113 <span class="meta">•</span> Tel: 210 7586

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# About the Course

## Lecture Hours
### - Monday: 08:40-10:30 (Office Hour: 10:40-11:30)
### - Thursday: 10:40-11:30

## Webpage: [keysan.me/ee281](http://keysan.me/ee281)
## Lecture Notes: [ozank.gitbooks.io/ee281/](http://ozank.gitbooks.io/ee281/)
###  Announcements: [COW.ceng.metu.edu.tr](http://cow.ceng.metu.edu.tr)

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# Grading: 
## - Midterms: 20% Each
## - Final: 30%
## - Laboratory: 20%
## - Quizes: 10%

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# Grading
### -To get a passing grade you need to have 100% attendance to labs

### -The following conditions should be met to take the final exam
#### -at least 50% of lab grades
#### -at least 30% of midterm exam grades
#### -at least 30% of in-class exam grades

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# Textbooks:
### - **Electric Circuits**, 8th Ed. James W. Nilsson, Susan A. Riedel, Prentice Hall, 2008. (Preferred)
### - **Electric Circuit Analysis**, 3rd Ed. D.E. Johnson, J.R. Johnson, J.L. Hilburn, P.D.Scott, Prentice Hall, 1997.
### - Any other reference book should be ok.

## Online Sources:
#### - A list of online sources are available in [keysan.me/ee281](keysan.me/ee281).

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# Course Outline: From Nilsson & Riedel:

####1. Basic Concepts (Ch. 1)
####2. Basic Laws (Ch. 2)
####3. Resistive Circuits (Ch. 3)
####4. Methods of Analysis (Ch. 4)
####5. Circuit Theorems (Ch. 4)
####6. Operational Amplifiers (Ch. 5)
####7. Capacitors And Inductors (Ch.6 upto 6.5)
####8. First Order Circuits (Ch. 7)
####9. Phasors and Sinusoids (Ch. 9)
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## Electric Circuit
Interconnection of electrical elements

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# A More Generalized View

## 1- Take a Real-World Problem

<img src="https://c2.staticflickr.com/4/3639/3403005971_6bdcbb8ac5_z.jpg" alt="Drawing" style="width: 500px;"/>
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# A More Generalized View

## 2- Simplify and represent it as a model

<img src="http://upload.wikimedia.org/wikipedia/commons/2/2a/Electric_circuit_RCL.jpg" alt="Drawing" style="width: 600px;"/>
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# A More Generalized View

## 3- Represent the Model Mathematically & Solve

`$$     \begin{array}{ccl}
        a_{11}x_1 & + a_{12}x_2 + \cdots + & a_{1n}x = 0 \\
        \;\vdots &  &\quad\vdots \\
        a_{m1}x_1 &+ a_{m2}x_2 + \cdots +& a_{mn}x_n = 0
      \end{array} $$`
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# Not Limited to Electric Circuits
--

## Thermal Problems

Thermal modelling of a thruster

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# Not Limited to Electric Circuits

## Mechanical Problems

<img src="http://upload.wikimedia.org/wikipedia/commons/d/d0/Shanghai_Transrapid_002.jpg" alt="Drawing" style="width: 400px;"/>
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Mechanical modelling of a magnetic levitation train
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class: center
# Remember the Big Picture!

<img src="https://raw.githubusercontent.com/ozank/ee281/master/images/problem_modelling.png" alt="Drawing" style="width: 200px;"/>
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#Embedded Systems

<img src="http://hsc.com/Portals/0/images/Blog/uploads/2014/02/bigstock-close-up-of-electronic-circuit-38621053.jpg" alt="Drawing" style="width: 700px;"/>
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# Recognize any of these?
--

<img src="http://mrickert.com/wp-content/uploads/2013/04/rasppi.jpg" alt="Drawing" style="width: 700px;"/>
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### [Raspberry Pi](https://www.raspberrypi.org/)

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# Recognize any of these?

<img src="https://www.arduino.cc/en/uploads/Guide/ArduinoNanoUSBCable.jpg" alt="Drawing" style="width: 600px;"/>
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### [Arduino](https://www.arduino.cc/)

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# Recognize any of these?

<img src="https://software.intel.com/sites/default/files/managed/ab/52/iot_edison.png" alt="Drawing" style="width: 700px;"/>
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### [Intel Edison](https://www.raspberrypi.org/)

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# Recognize any of these?

<img src="https://www.filepicker.io/api/file/GRfBJYSMSgel7wOh4mwH" alt="Drawing" style="width: 600px;"/>
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### [Particle Photon](https://www.particle.io/)
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# Any questions up to here?

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# Basics
## SI Units:
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###- kg, m, N, V, A ...
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## SI Prefixes:

- Mega (M)   \$10^6\$
- Kilo (k)   \$10^3\$
- Mili (m) \$10^{-3}\$
- Micro (\$\mu\$)   \$10^{-6}\$
- Nano (n)   \$10^{-9}\$
- Pico (p)    \$10^{-12}\$

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# Electric Charge

The unit of charge is Columbs (C), which is equal to charge of \$6.24 \times 10^{18}\$ electrons.

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# Current

#### Current is the rate of charge flow: $$i=\frac{dq}{dt}$$.

### 1 A equals to 1 Coulomb/seconds.

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# Voltage

Voltage is related to the strength of the electric field. It is analogous to pressure in a hydraulic circuit.

###! Voltage is always measured between two points, that is why it is also called potential difference.

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## Analogy to Hydraulic System
#### - Voltage --> Pressure
#### - Electric Current --> Water Current
#### - Tap Resistance --> Resistance

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# Power

Power is the rate of energy (dissipating or absorbing), denoted by P:

### $$P=\frac{dw}{dt}$$

In electric circuits power is equal to multiplication of voltage and current.

### $$Power = Voltage \times Current$$
### $$P = VI$$

The unit of power is **Watt**.

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# Energy
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The unit of energy is Joules, which is also equal to watt.seconds.

#### $$w=\int P(t) dt = \int V(t) I(t) dt$$

#### It is also common practice to express electrical energy in kilo-watt hours (**kWh**).

Example: Electricity bills([photo1](https://raw.githubusercontent.com/ozank/ee281/master/images/fatura1.jpg), [photo2](https://raw.githubusercontent.com/ozank/ee281/master/images/fatura2.jpg)) are calculated in terms of kWh.

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# Any questions?

## You can download this presentation from: [keysan.me/ee281](http://keysan.me/ee281)