FROM ELECTRONS TO BITS ............................................................................................................................. 5
INFORMATION AND ELECTRICAL SIGNALS ..................................................................................................... 5
ANALOG SIGNALS............................................................................................................................................ 5
AMERICAN STANDARD CODE FOR INFORMATION INTERCHANGE ................................................................ 7
NUMBERS IN DECIMAL (10) AND HEXADECIMAL (16) NOTATIONS ............................................................... 7
ALTERNATIVE WAY OF CALCULATING HEXADECIMAL: .................................................................................. 9
SEMAPHORE ................................................................................................................................................. 10
TELEGRAPH ................................................................................................................................................... 11
RADIO ............................................................................................................................................................ 11
FUNDAMENTAL MODEL OF COMMUNICATION........................................................................................... 12
WHERE IS THE INFORMATION IN A SIGNAL? ................................................................................................ 12
ELECTROMAGNETIC SPECTRUM................................................................................................................... 12
THE FUNDAMENTAL SIGNAL: THE SINUSOID ............................................................................................... 14
SIGNAL ANALYSIS AND SYNTHESIS................................................................................................................ 16
THE TWIN BROTHERS SIN AND COS .............................................................................................................. 16
ANGLE ADDITION AND SUBSTRACTION THEOREMS .................................................................................... 17
CAN YOU DETERMINE AN EQUATION OF THE SINE WAVE FROM THE GRAPH? .......................................... 17
AMPLITUDE MODULATION (AM).................................................................................................................. 23
FREQUENCY MODULATION (FM).................................................................................................................. 24
INFORMATION SIGNAL SYNTHESIS FROM SINE WAVES ............................................................................... 24
MEET HARRY AND CLAUDE ........................................................................................................................... 26
ANALOG-DIGITAL AND DIGITAL-ANALOG CONVERSIONS ............................................................................ 26
REGULAR SAMPLING OF ANALOG SIGNALS .................................................................................................. 27
SIGNAL RECONSTRUCTION FROM SAMPLES - EXACT ................................................................................... 28
THE TWIN BROTHERS SIN AND COS .............................................................................................................. 28
SIGNAL RECONSTRUCTION FROM SAMPLES - ALIASED................................................................................ 29
ALIASING IN 2D SPATIAL SIGNALS (IMAGES) ................................................................................................ 30
ALIASING IN SYNTHETIC IMAGES .................................................................................................................. 31
TRANSMISSION OF INFORMATION ............................................................................................................... 32
THE NYQUIST-SHANNON SAMPLING THEOREM .......................................................................................... 32
TRANSMISSION OF POWER .......................................................................................................................... 32
THE PHYSICS OF ELECTRON FLOW ................................................................................................................ 32
ELECTRON FLOW IN COPPER WIRES ............................................................................................................. 33
THE BOHR’S MODEL OF THE COPPER ATOM ................................................................................................ 33
NETWTON’S CRADLE .................................................................................................................................... 35
THE RESISTANCE DEPENDS ON THE TEMPERATURE .................................................................................... 36
THE RESISTANCE DEPENDS ON THE RESISTIVITY OF THE MATERIAL ............................................................ 36
THE DRIFT SPEED OF ELECTRONS ................................................................................................................. 37
A 60 WATTS LIGHT BULB ON 230 VOLTS....................................................................................................... 37
1
, AT WHAT SPEED DO THE ELECTRONS MOVE INSIDE THE WIRE? ................................................................. 37
THE “SPEED” OF ELECTRICITY ....................................................................................................................... 40
ELECTRIC CURRENT, VOLTAGE, RESISTANCE, POWER ................................................................................. 41
FOUR FUNDAMENTAL STATES OF MATTER .................................................................................................. 43
ELECTRICAL GRIDS ........................................................................................................................................ 44
WHY ARE THE TUBES THICK? ........................................................................................................................ 45
ANALOGY BETWEEN HYDRAULIC AND ELECTRIC POWER ............................................................................ 50
ELECTRICAL CURRENT, VOLTAGE, RESISTANCE, POWER ............................................................................. 51
OHM’S LAW................................................................................................................................................... 51
AMMETER ..................................................................................................................................................... 52
VOLTMETER .................................................................................................................................................. 53
EXERCISES WITH ELECTRIC RESISTANCES ..................................................................................................... 53
WHAT IS DRAWING MOST OF THE POWER: THE HEATING OR THE MOTOR? .............................................. 55
EXERCISES WITH ELECTRIC CIRCUITS ............................................................................................................ 55
ELECTRIC CIRCUITS ....................................................................................................................................... 60
SCHEMATIC OF THE CIRCUIT ........................................................................................................................ 61
RESISTORS, CAPACITORS, AND INDUCTORS ................................................................................................. 62
PASSIVE CIRCUIT ELEMENTS ......................................................................................................................... 62
RESISTORS COLOR CODES ............................................................................................................................. 63
FUNDAMENTALS OF ELECTRIC CIRCUITS...................................................................................................... 63
TWO IMPORTANT PROPERTIES OF CIRCUITS ............................................................................................... 64
EXAMPLE OF SIMPLE SCHEMATIC: ............................................................................................................... 67
SEE EXERCICE SHEET ..................................................................................................................................... 68
ELECTRIC CAPACITORS .................................................................................................................................. 71
RESISTORS, CAPACITORS, AND INDUCTORS ................................................................................................. 71
TWO CONDUCTIVE PLATES SEPARATED BY A DIELETRIC .............................................................................. 71
ELECTRIC CAPACITANCE OF A CAPACITOR ................................................................................................... 72
ELECTRIC RC CIRCUIT (RESISTORS AND CAPACITORS) .................................................................................. 74
RESISTORS FOLLOW THE CURRENT FLOW IN AC CIRCUITS .......................................................................... 75
LITHIUM-ION RECHARGEABLE BATTERIES (CAPACITORS)............................................................................ 77
BATTERIES STORE ENERGY (POWER X TIME) ................................................................................................ 78
ENVIRONMENTAL IMPACT ........................................................................................................................... 78
HOW COULD YOU STORE THE ENERGY IN ANOTHER WAY THAN WITH LITHIUM-ION BATTERIES? ............ 79
DIFFERENCE BETWEEN ELECTRIC AND ELECTRONIC CIRCUITS .................................................................... 81
DIODES .......................................................................................................................................................... 83
REAL CURRENT FLOW ................................................................................................................................... 89
2
, TRANSISTORS ................................................................................................................................................ 90
HOW INTEGRATED CIRCUITS ARE MADE ...................................................................................................... 93
EXERCISES WITH ELECTRONIC CIRCUITS ...................................................................................................... 94
AC/DC ............................................................................................................................................................ 98
FOLLOW UP-EXERCISES WITH ELECTRONIC CIRCUITS.................................................................................. 98
PUZZLE GAMES WITH DIODES .................................................................................................................... 102
THE INDUSTRIAL AGE (1840 -…) - TRANSMISSION OF POWER ................................................................... 104
THE INFORMATION AGE (1971-…) - TRANSMISSION OF INFORMATION ................................................... 104
ELECTRO-MECHANICAL COMPUTERS ........................................................................................................ 105
THEN CAME THE INTEGRATED TRANSISTOR .............................................................................................. 107
NEW INTEGRATED CIRCUITS (IC) ARE FIRST PROTOTYPED BEFORE MASS PRODUCTION AT A FOUNDRY (I.E.,
TSMC IN TAIWAN). ......................................................................................................................................... 110
LOGIC GATES ............................................................................................................................................... 112
LOGIC CIRCUITS........................................................................................................................................... 116
SOME HOME COMPUTERS AND GAME CONSOLES FROM 80’S ................................................................. 117
FAMILY OF COMPUTER CHIPS..................................................................................................................... 118
CENTRAL PROCESSING UNIT (CPU) ARCHITECTURE ................................................................................... 120
IMPERATIVE COMPUTER PROGRAMMING ................................................................................................ 121
THE 6502 CPU CAN EXECUTE 56 DIFFERENT INSTRUCTIONS ..................................................................... 122
ADDING BINARY NUMBERS WITH LOGIC CIRCUITS .................................................................................... 123
BINARY NUMBERS REPRESENTATION ........................................................................................................ 123
SUM OF POWERS OF TWO NUMBERS ........................................................................................................ 123
CONVERT FROM DECIMAL TO BINARY REPRESENTATIONS ....................................................................... 124
ADDITION OF BINARY NUMBERS ................................................................................................................ 124
A LONGER EXERCISE WITH 8-BITS ARITHMETIC ......................................................................................... 125
BINARY ADDITION WITH LOGIC GATES ....................................................................................................... 125
DIGITAL LOGIC CIRCUIT SYMBOLS .............................................................................................................. 125
HALF-ADDER CIRCUIT ................................................................................................................................. 126
FULL-ADDER CIRCUIT .................................................................................................................................. 127
TRUTH TABLE .............................................................................................................................................. 128
FULL-ADDER CIRCUITS IN CASCADE (SERIES).............................................................................................. 129
THE NOT LOGIC GATE ................................................................................................................................. 130
THE NOT (INVERTER) LOGIC GATE ................................................................................................................. 130
AND AND OR ARE NOT UNIVERSAL LOGIC GATES ........................................................................................ 131
USING THE AND AND NOT SET ..................................................................................................................... 131
LOGIC CIRCUIT EQUIVALENCES .................................................................................................................. 132
NAND IS A UNIVERSAL LOGIC GATE ............................................................................................................ 134
LOGIC CIRCUIT EQUIVALENCES – MORGAN’S LAWS .................................................................................. 135
HOMEWORK: LOGIC CIRCUIT EQUIVALENCES – EXAMPLE WITH THE XOR GATE ...................................... 136
LOGIC CIRCUIT SIMPLIFICATION ................................................................................................................. 137
EXAMPLE OF SIMPLIFICATION – STEP-BY-STEP .......................................................................................... 137
LOGIC – ANALYTICAL WAY: ......................................................................................................................... 137
LOGIC CIRCUIT: HOMEWORK ..................................................................................................................... 139
(THE ADDITIONAL FILE IS CLEARER – NOT REALLY IMPORTANT WHAT IS BELOW HERE) .......................... 141
4
,Lecture 1
FROM ELECTRONS TO BITS
All electrons and bits are related. The bits is a representation of information as binary state
(zeros or ones) and electrons are particles that move or not.
INFORMATION AND ELECTRICAL SIGNALS
(1) How is information communicated electrically?
(2) How do you extract information from a signal?
(3) How are analog signals communicated digitally? (An analog is like a physical signal)
>> signals = can be voice, music, video, the text you type,…
è A signal is a function of time and/or space.
ANALOG SIGNALS
SPEECH RECORDING OF THE LETTER “e”. The signal is a function. If something goes up, it must
go back (=control of the absolute position of the membrane, it is not just a dumping effect).
The amplitude can be negative. In the case, the time is still discrete because it is a digital
recording of this analog signal.
We see that there is a lot of information in the sampling of the sound. 44.1 kHz means over
44.1 per second, we measure the state of the amplitude, we record the position of the
membrane (= a lot of information).
SOUND FROM A SYNTHESIZER INSTRUMENT. Electronic equipment. Here, we get a very clean
signal. It is a simple signal made of sinusoid. This is an artificial signal. The goal of synthesis is to
approximate the reality using simple electronics and simple physics of the sinusoid voice.
5
,There is a motion. This motion moves a little magnet which will modulate the flow of electricity
through the cable.
When you write a text, there is a sequence of letters. If you encore id digitally, you associate it
with numbers (A with 65, B with 66). There is a table with common agreement (ASCII: American
Standard Code with Information Interchange).
With this table, we can interpret numbers and replace them with a glyph of that number. The
graph is a function of that representation. This function is discrete (index instead of time
dimension) and you have a value (also discrete). The text is a function where the time is
discretized into text and it gives ?
6
,AMERICAN STANDARD CODE FOR INFORMATION INTERCHANGE
The 0w02 and so on: (hexadecimal notation) way to write a number that is really used in the
digital word by computer scientists, engineers and so on.
NUMBERS IN DECIMAL (10) AND HEXADECIMAL (16) NOTATIONS
7
,When you have 4 bits you have 16 possibilities (because we group zeros and ones by 4)
0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f = 16 digits in hexadecimal notation
The second line is the same but in hexadecimal notation. F is the glyph in hexadecimal notation.
,ALTERNATIVE WAY OF CALCULATING HEXADECIMAL:
479 (dec) to (hex) :
= 29.9375 = 29 with remainder 15 (calculated from 0.9375*16)
Then: = 1.8125 = 1 with remainder 13 (calculated from 0.8125*16)
Then: = 0.0625 = 0 with remainder 1 (calculated from 0.0625*16)
15 -> F (Least Significant Digit)
13 -> D
1 -> 1 (Most Significant Digit)
à So, we read it from bottom to top. 47910 à 1DF16
D3E5C (hex) to (dec):
D à 164
3 à 163
E à 162
5 à 161
C à 160
An imagine is a function of 2D space.
What is a television signal? What kind of dimension? 3D.
A television signal is a function of time and 2D space. The moving image and sound over it
doesn’t mean that the dimension is 4D. It is another signal synchronized on it.
Numbers are represented with digits. In hexadecimal notation we have 16 digits.
With two digits in hexadecimal notation, you can represent 16*16 different numbers.
9
, Lecture 2
SEMAPHORE
This doesn’t work with electricity because electricity wasn’t invented yet. It was an invention
of 1792.
It is a semaphore. There is a guy that pull on strings and animate this device to make signs.
When you wanted to transmit a message from Paris to Lyon, you transmitted the message with
gesture, and somebody was receiving the message using a telescope and redoing the message.
It is a mean of transmitting information using codes. The information is encoded into visual
signs and it is broadcasted.
The medium is air and the particle that carry information is the photon. Because it is a visual
information, we use photons à Optical transfer of information.
10
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