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Foundations of Technology
Basic CircuitsBasic Circuits
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
Teacher Resource – Unit 4 Lesson 4
The BIG IdeaThe BIG Idea
Big Idea:
Troubleshooting allows users to continue to use and maintain the proper operation of a system or product.
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
Basic CircuitsBasic Circuits
All electronic circuits have a path for electrons to flow and an energy source.
Electrons will flow from the negative(-) to the positive(+).
The amount of electron flow will depend on resistance.
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
-
+
Direct CurrentDirect Current
Direct Current (DC) electrons flow in only one direction.
Examples: a battery, hand held electronics such as an iPod and other devices like an automobile
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
Alternating CurrentAlternating Current
Alternating Current (AC) electrons flow back and forth, negative (-) to positive (+) to negative (-)
Examples: the electrical appliances at your house
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
The AtomThe Atom
All matter is made of atoms.
The atom is made of three things:
Protons
Neutrons
Electrons
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
P NP
NP
N
NP
e-
e-
e-
e-
Electrons rotate around the group of proton and neutrons.
When electrons move from one atom to the next, it is called electron flow.
ElectronsElectrons
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
P NP
NP
N
NP
e-e-
e-
e-
Opposite electrical charges always attract and like electrical charges always repel.
Balanced atoms normally have an equal number of electrons and protons, which means they are electrically neutral.
ElectronsElectrons
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
P NP
NP
N
NP
e-e-
e-
e-
e- e-
e+ e-
Ion particles occur when an atom loses or gains an electron causing an imbalance.
When an imbalance occurs, Ion's will take or release an electron to become balanced again, causing electron flow.
IonsIons
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
P NP
NP
N
NP
e-e-
e-
e-
Ion’s can be charged:
Positive (+), which has one less electron than proton.
Negative (-), which has one more electron than proton.
The positive Ion attracts to a negative Ion to become balanced.
IonsIons
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
P NP
NP
N
NP
e-e-
e-
e-
Electrons rotate around the atom at different orbits.
Bound electrons orbit around the nucleus on the inner rings
Free electrons are loosely held and orbit around the outermost ring which is known as the valance ring
Electron OrbitsElectron Orbits
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
e- e-
e-
e-
+
e-
e-
e-
e-
e-
e-
e-
e-e-
e-
e-
e-
e-e-
e-
e-
e-
e-e-e-
e-e-e-
e-
e-
An insulator is any material that prevents the flow of electrons.
Insulators typically have five to eight free electrons in the outer ring, which means they are tightly held to the atom and cannot easily move.
Insulator material includes glass, rubber and plastic.
InsulatorsInsulators
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
e- e-
e-
e-
+
e-
e-
e-
e-
e-
e-
A conductor is any material that easily allows electrons to flow.
Conductors typically have one to three free electrons in the outer ring, which means they are loosely held to the atom and can easily move.
Conductor material includes copper and gold.
ConductorsConductors
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
e- e-+
e-
e-
e-
A semiconductor is neither a good conductor or insulator.
Semiconductors have exactly four free electrons in the outer orbit and are commonly used to manufacture diodes, transistors, and integrated circuit chips.
Semiconductor material includes carbon, silicon, and germanium.
SemiconductorsSemiconductors
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
e- e-+
e-
e-
e-
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Proposed by George Ohm, and is the relationship between Voltage, Current and Resistance.
Ohm suggested that if you double the Voltage across something that provides resistance, then the current would double.
Voltage (V) = Current (I) X Resistance (R)
Ohm’s LawOhm’s Law
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
-
+V
R
I
Voltage is the electrical force that moves electrons through a conductor.
Voltage is electrical pressure that pushes electrons.
VoltageVoltage
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
V
I R
Current is the quantity or flow rate of electrons moving past a point.
Current flow is also known as amperage, or amps for short.
CurrentCurrent
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
V
I R
Resistance is the force that reduces or stops the flow of electrons and opposes voltage.
ResistanceResistance
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
V
I R
In a Series circuit, the current through two or more resistors is the same, and the circuit is connected in a series.
The total resistance of the collection is the sum of the individual resistances.
In series, electrons have only one path to follow to complete the circuit and must travel through all components.
Resistors in SeriesResistors in Series
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
In a Parallel circuit, the voltage through two or more resistors is the same, and the circuit is connected in parallel.
The total resistance of the collection is divided among the three resistors .
In parallel, electrons have multiple paths to follow to complete the circuit and do not need to travel through all components in the circuit to do so.
Resistors in ParallelResistors in Parallel
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
Parts of the Electronics Parts of the Electronics KitKit
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
2 Battery Snaps
Battery
Speaker
SCR Capacitors
PhotocellPush Button
Transistors
Diode3 LED’s
555 Timer
Potentiometer
15Wires
Solderless Breadboard
Parts of the Electronics Parts of the Electronics KitKit
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
LED Resistor 3904 Transistor Speaker
Diode Photocell 3906 Transistor Push Button
“Can” Capacitor Potentiometer Battery SCR
Ceramic Disc Capacitor
Parts of the Electronics Parts of the Electronics KitKit
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
10
ohm
(B
row
n, B
lack
, B
lack
, G
old
)
2 @
47 o
hm
(Yello
w, V
iole
t,
Bla
ck, G
old
)
2 @
100
ohm
(B
row
n, B
lack
, B
row
n,
Gold
)
3 @
220
ohm
(R
ed,
Red
, B
row
n, G
old
)
3 @
330
ohm
(O
range, O
range
Bro
wn,
Gold
)
47
0 o
hm
(Yello
w,
Vio
let,
Bro
wn
, G
old
)
4 @
1K
ohm
(B
row
n, B
lack
, R
ed, G
old
)
2.2
K o
hm
(R
ed, R
ed, R
ed,
Gold
)
3.3
K o
hm
(O
ran
ge, O
ran
ge, R
ed, G
old
)
2 @
6.8
K o
hm
(B
lue, G
ray, R
ed, G
old
)
3 @
10K
ohm
(B
row
n, B
lack
, O
ran
ge, G
old
)16
K o
hm
(B
row
n, B
lue, O
range,
Gold
)
2 @
33K
ohm
(O
ran
ge, O
range,
Ora
nge, G
old
)
12
0K
ohm
(B
row
n, R
ed, Yello
w,
Gold
)
47
0K
ohm
(Yello
w,
Vio
let,
Yello
w,
Gold
)
Resistors have four (4) color bands on them called the “color code”
Band 1 = 1st Digit
Band 2 = 2nd Digit
Band 3 = Multiplier.
Band 4 = Tolerance
Gold = 5%
Silver = 10%
Color CodesColor Codes
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
The Breadboard includes two sides (a-e and f-j) and the “ditch” or the space in the middle.
The holes are connected by rows not columns.
Building a CircuitBuilding a Circuit
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
Build the circuit below:
Practice Building a CircuitPractice Building a Circuit
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
-
+9Volts
R = 1000 Ohms
I
1000 ohms resistor (brown, black, red, gold)
Use your simple circuit and measure for Volts, Current and Resistance.
Practice Building a CircuitPractice Building a Circuit
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
-
+9Volts
R
I
Use the multimeter to measure the resistance.
Use the multimeter to measure voltage
Place the digital multimeter in series to measure current.
1000 ohms resistor (brown, black, red, gold)
Do the math using Ohm’s Law to find the actual value of the resistor - What does it measure?
Practice Building a CircuitPractice Building a Circuit
© 2013 International Technology and Engineering Educators Association, STEMCenter for Teaching and Learning™ Foundations of Technology
-
+9Volts
R
I
Use the multimeter to measure the resistance.
Use the multimeter to measure voltage
Place the digital multimeter in series to measure current.
1000 ohms resistor (brown, black, red, gold)