Download Electricity and Electronics Module

George
Westinghouse, Jr.
(1846 – 1914)
Thomas Alva
Edison
(1847 – 1931)
Electricity
Electricity
&
Electronics
Bruce E. Amrein, MES, MBA, CTS
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Igniting the Spark of Science!
ELECTRICITY: AN ANALOGY
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Igniting the Spark of Science!
VOLTAGE (E)
The volt is a measure of electric potential.
Electrical potential is a type of potential
energy, and refers to the energy that could
be released if electric current is allowed to
flow.
The SI* unit of voltage is the Volt.
E= Electro-motive Force; the voltage
developed by any source of electrical
energy such as a battery
Alessandro Volta
(1745 – 1827)
* SI= International System of Units
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Igniting the Spark of Science!
CURRENT (I)
An electric current is a flow of electric
charge. In electric circuits this charge is
often carried by moving electrons in a
wire.
The SI* unit for measuring an electric
current is the ampere (A), which is the
flow of electric charge across a surface at
the rate of one coulomb per second.
Electric current is measured using a
device called an ammeter.
1000 milliamps = 1 Ampere
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André-Marie Ampère
(1775 – 1836)
Igniting the Spark of Science!
RESISTANCE (Ω)
The resistance of an electrical conductor
is a measure of the difficulty to pass an
electric current through that conductor.
Electrical resistance shares some
conceptual parallels with the notion of
mechanical friction.
The SI unit of electrical resistance is the
Ohm [Symbol: Ω (Omega)]
A resistor is an electrical component.
Resistors act to reduce current flow, and,
at the same time, act to lower voltage
levels within circuits
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Georg Simon Ohm
(1789 – 1854)
Igniting the Spark of Science!
DIRECT CURRENT or ALTERNATING CURRENT
• Direct current is the one way
flow of electrical charge from a
positive to a negative charge.
• Batteries produce direct
current.
• Direct Current is different than
alternating current because the
charge only flows in one
direction.
• Thomas Edison is credited for
promoting direct current.
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Alternating Current: In
the US, 60 cycles per
second, or 60 Hertz,
named after Heinrich
Rudolf Hertz (1857 –
1894)
• Alternating Current is when
charges flow back and forth from
a source.
• AC flows in the form of a sine
wave, back and forth– 60 times
per second in the U.S.
• Nikola Tesla was a pioneer in the
advancement of alternating
current.
• It is the way we receive our
electricity (for our houses,
businesses, etc.)
Igniting the Spark of Science!
SYMBOLOGY & NOTATION
• Voltage, symbolized by the letters “E” or
“V”; measured in volts.
• Current, symbolized by the letter “I”;
measured in amps– short for amperes.
• Small currents, symbolized by the letter “I”;
measured in milliamps (1/1000th of an amp).
• Resistance, symbolized by the letter “R”,
measured in ohms (Ω).
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Igniting the Spark of Science!
OHM’S LAW
• Defines the relationship
between voltage (E), current
(I), and resistance (R).
• These basic electrical units
apply to direct current, or
alternating current.
• Ohm’s Law is the foundation of
electronics and electricity.
• Ohm established in the late
1820s that if a voltage was
applied to a resistance then
“current would flow and then
power would be consumed.”
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Igniting the Spark of Science!
ELECTRICAL SYMBOLS
Wire
Load
(Resistor)
Switch
Batteries
Lamp
AC power
AN ELECTRICAL CIRCUIT
PICTORIAL
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SCHEMATIC
Igniting the Spark of Science!
WHAT YOU NEED TO KNOW
ABOUT RESISTORS
Resistors are often in series and parallel
configurations in circuits
Series combination
R1 +
R2 + R3 =
RT
Parallel combination
1
R1
10
+
1
R2
+
1
R3
=
1
Req
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LAMPS IN SERIES OR PARALLEL
CIRCUITS
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MEASUREMENTS: DIGITAL MULTIMETER
DC VOLTAGE
DC AMPS
(ma)
RESISTANCE
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LAB: RESISTOR COLOR CODES
•
•
•
•
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Goals:
Learn Color Codes
Measure Resistance
Measure DC Voltage
Measure Current
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LAB:
RESISTOR COLOR CODES & MEASUREMENT
Goal
• Measure Resistance
SET METER ON 2000 Ω SCALE
Ω
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GREEN
BROWN
BROWN
BROWN
BLACK
RED
RED
BLACK
RED
ORANGE
WHITE
Igniting the Spark of Science!
RED
LAB:
RESISTOR COLOR CODES & MEASUREMENT
SET METER ON 2000 Ω SCALE
510 Ω
15
1000 Ω
2000 Ω
3900 Ω
Igniting the Spark of Science!
LAB:
RESISTOR COLOR CODES & MEASUREMENT
Goal:
• Measure Resistance
• Series Combinations
• Parallel Combinations
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LAB:
RESISTOR COLOR CODES & MEASUREMENT
Goal:
• Measure Resistance
• Series Combinations
R1
510 Ω
+
R2
=
RT
+ 1000 Ω = 1510 Ω
• Parallel Combinations
1
R1
1
3900 Ω
17
+
+
1
R2
1
2000 Ω
=
=
1
Req
1
1322 Ω
Igniting the Spark of Science!
LAB:
VOLTAGE AND CURRENT
Goal:
• Measure Voltage
• Measure Current
9.40 v
V
SET METER ON DC
VOLTAGE SCALE:
20 VOLTS
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Igniting the Spark of Science!
LAB:
VOLTAGE & CURRENT– BUILD A CIRCUIT
Goal:
• Measure Voltage
• Measure Current
R1
510 Ω
+
R2
+ 1000 Ω
= RT
= 1510 Ω
RED = PLUS (+)
R1
R2
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R1= 510 Ω
R2 = 1000 Ω
Igniting the Spark of Science!
LAB:
MEASURE VOLTAGE & CURRENT
Goal:
• Measure Voltage
• Measure Current
SET METER ON DC
AMPERE SCALE:
20 mA
mA
6 mA
V
I
?? v
VT
R1
V2
V
R1= 510 Ω
R2 = 1000 Ω
20
R2
V3
SET METER ON DC
VOLTAGE SCALE:
20 VOLTS
Igniting the Spark of Science!
LAB:
MEASURE VOLTAGE & CURRENT
Goal:
• Measure Voltage
• Measure Current
mA
VT
9.4
Volts
V1
3.18
Volts
V2
6.22
Volts
I
6.2
mA
I
VT
R1= 510 Ω
R2 = 1000 Ω
R1
R2
V2
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V1
Igniting the Spark of Science!
RESISTANCE: A PRACTICAL EXAMPLE
ELECTRICAL POWER DISTRIBUTION
100,000 V at 10 Amperes
Voltage Loss= 1%
10,000 V
TOP EXAMPLE
ΔE= IR
ΔE= 10A x 100 Ω
ΔE = 1000 volts
100 miles @ 1 Ω per mile = 100 Ω
Power = 1 Million Watts (1 MW)
Wire= #3AWG Copper
10,000 V at 100 Amperes
BOTTOM EXAMPLE
ΔE= IR
ΔE= 100A x 100 Ω
ΔE = 10,000 volts
Voltage Loss= 100%
10,000 V
X
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X
Igniting the Spark of Science!
WHAT CAN YOU DO WITH A
MULTIMETER?
• Check battery voltage (DC VOLTS)
• Check Power Supplies (AC or DC VOLTS)
• Check fuses (RESISTANCE)
• Check household receptacles
(AC VOLTS)
120 Volts (AC)
0 Volts
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120 Volts (AC)
Igniting the Spark of Science!
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Igniting the Spark of Science!