Course Reflection
AK47
hacker_ch.9.pptxElectronics
Chapter 9 Hacker
ETSC 101 Chapter 9 Hacker
1
What is Electricity???
Simply put, the flow of electrons through a material.
Conductive materials: Generally less than 4 valence electrons.
Insulator materials: Generally more than 4 valence electrons.
Semiconductors: 4 valence electrons.
ETSC 101 Chapter 9 Hacker
Electrons flow through conductive materials because less bond energy is holding the outer valence electrons to the atom, so when an attractive force is imposed on the electrons by a positive electrical voltage, they are willing to move.
The bond force is too high in atoms with a valence greater than 4 so they will not conduct electricity.
Semiconductor materials are special because using the same material, atoms can be added in a specific order to make some parts of the material conductive and other parts insulating.
Bring out marbles and tubing
2
ETSC 101 Chapter 9 Hacker
Variables of Electricity
Voltage(Volts) – Potential Energy – Difference in Electronegativity
Current(Amps) – Kinetic Energy – Electrons Moving
Resistance(Ohms) – Conversion of energy into heat or work.
ETSC 101 Chapter 9 Hacker
The electrical variables can be correlated to forms of energy. There are many more variables of electricity and electronics but these are the three primary ones. Capacitance and inductance are other variables.
4
ETSC 101 Chapter 9 Hacker
Series
Parallel
Loop
Node
When components are in series, they all get the same current and distributed voltage.
When components are in parallel, they all get the same voltage, but distributed current.
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Laws
Ohms Law: V=IR
P = VI
Kirchhoff’s Voltage Law: ∑V = 0 in a loop
Kirchhoff’s Current Law: ∑I = 0 in a node.
ETSC 101 Chapter 9 Hacker
A node is a junction in a circuit.
A loop is one single square of a circuit.
Show examples on board.
6
Design This Circuit
Draw and calculate the voltage and current in each component of the circuit. Use the following.
9V battery
Two lightbulbs (3V; 10 mA light bulbs): One green and one red.
A switch that controls each light bulb
Any resistors needed
ETSC 101 Chapter 9 Hacker
Alternating Current (AC)
Amplitude
Frequency
Waveform
ETSC 101 Chapter 9 Hacker
X axis is time and the y axis is voltage.
Frequency describes the time for one cycle to occur, or one pulse. Sound is described in terms of frequency of vibrations, so AC is good for communicating sounds and messages.
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Components
Resistors: Load the circuit.
Capacitors: Storage space for electrons.
Inductors: Storage space for magnetic field.
Transformers: Two inductors used to transform voltage level.
Switches: On and off for the circuit.
Transistors: Switch controlled by voltage level
Integrated circuits: Millions of interconnected transistors and other components.
ETSC 101 Chapter 9 Hacker
Transistors make basic programming possible: If this voltage, go down this path; if that voltage, go down that path. Logic functions can be created such as IF AND OR statements.
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