Download Electrical Engineering

Pre-Class Monday 10-22-12
What do you think an Electrical Engineer does?
Electrical Engineering
The world's leading professional association
for the advancement of technology
Electrical Specifics
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The most common/populated engineering field
Responsible for the design, development, testing,
and supervision of the manufacture of electrical
equipment (from household appliances to satellite
systems)
Any product that has electricity falls under their
“jurisdiction”
Main areas: Power generation, transmission, and
distribution; communications; computer electronics;
electrical equipment manufacturing
Pre-Class Tuesday 10-23-12
Why is Electrical Engineering so
important to everyday life?
8 Major Categories
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Computers  Computer Engineering branch
Communications  Global Positioning Systems (GPS), fiber
optics, and lasers
Circuits and solid-state devices  making electronic devices
smaller and more efficient
Control  reliable, efficient, and safe electronics
Instrumentation  measuring how an electronic device is
performing as compare to its specs
Signal processing  filtering, amplifying, and modifying any
signal (digital or otherwise)
Bioengineering  non-invasive techniques (Magnetic
Resonance Imaging, MRI, or Computer Automated
Tomography, CAT, scan)
Power  the most traditional of them all, electrical power
Making a Testing Apparatus
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Objective
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Materials
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Design and construct a battery holder.
Index card
2 paper clips
■ C-cell battery
■ 10 cm of masking tape
Procedures

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Design a battery holder for a C-cell that allows
for connection to wires on both sides.
Use materials to construct it.
Use your testing apparatus in the following lab.
Pre-Class Wednesday 10-24-12
What is the
word in
black? If it
were resting
on a mirror or
a light were
behind it to
cast a shadow
below it,
what would it
read?
CONDUCTIVE MATERIALS


INSULATOR
charges do not flow
freely
impedes electricity


CONDUCTOR
charges flow freely
allows electricity to
flow through it
NOTE: Wood is not a good conductor nor insulator.
Insulation vs. Conduction

Objectives

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Materials
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To determine what conducts electricity
Wires
Light bulbs
Procedures

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Divide into groups of 2 or 3.
Obtain materials from cart.
Test 8-10 items.

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C-cell Battery
Other?
Pre-Class Thursday 10-25-12
If 5 cats can catch 5 rats in 5 minutes, how
many cats do you need to catch 100 rats in
100 minutes?
5
The largest, most prominent engineering field
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Aerospace
Antenna
Broadcast
Communications
Computer
Control Systems
Lasers
Power
Robotics
Signal Processing
Wireless
Starting salary in 2011: $61,420 (BS),
$72,340 (MS), $88,970 (PhD)
Average salary in 2005: $51,773
CURRENT

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The flow of positive
charges (in theory)
The flow of negative
charges (in real life)
A river of electrical
energy that moves
through a wire
Must have a closed
continuous loop to work

Current
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Measured in Volts
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Amps or A
Volts or V
Measured in Ohms
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ohms (W)
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Measures Amps
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Measures Volts
measures current
Voltmeter

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impedes current
uses energy
Ammeter
Measured in
Amperes

voltage (source)
Resistance


number of charges
that travel per second
Battery

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measure voltage
http://regentsprep.org/Regents/physics/phys03/bsimplcir/default.htm
Schematics

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A sketch of what the
circuit looks like
Represents how the
current will flow in
the circuit
Specific types of
symbols for sketches
Pre-Class Friday 10-26-12

Draw and label a circuit with the proper schematic
symbols containing a battery, a resistor, and a switch.
CIRCUITS

PARALLEL
 current has multiple
paths to follow
 broken circuit may
not stop electrical
flow
 voltage is the same
through each resistor
 current adds for each
http://www.regentsprep.org/Regents/physics/phys03/bparcir/default.htm

SERIES
 current has only one
path to follow
 broken circuit stops
all flow of electricity
 current is the same
through each resistor
 voltage adds for each
http://www.regentsprep.org/Regents/physics/phys03/bsercir/default.htm
Schematics Lab
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Objective
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Materials
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Battery holder
Wires
2 light bulbs
■ C-cell battery
■ Voltmeter
■ Ammeter
Procedures
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Construct two simple circuits.
Draw schematics of simple circuits.
Construct a simple series circuit.
Measure and record the current and voltage through the light bulb.
Draw a schematic of the series circuit.
Construct a simple parallel circuit.
Measure and record the current and voltage through each light bulb.
Draw a schematic of the parallel circuit.
Questions
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The ammeter was to be wired in series. Explain why.
The voltmeter was to be wired in parallel. Explain why.
For a circuit to work (assuming you have power and proper equipment), what is vital?
Pre-Class Monday 10-29-12

At the recent web developer's bowling match, two games were
played. Kev beat Stuart in both games, also Richard beat John in both
games. The winner in game 1 came second in game 2. Richard won
game 2 and John beat Stuart in game 1. No player got the same
placing twice. Can you determine who finished where in each game?
Name
Kev
Richard
John
Stuart
#1
1
2
3
4
#2
2
1
4
3
OHM’S LAW

Ohm defined how current(amps), voltage(volts),
and resistance(ohms=W) relate
V = IR
V : voltage of battery (e.g. 9 V battery)
 I : current (number of charges per second)
 R : resistance (e.g. light bulb, stereo, etc.)

Electrical Power
P=
2
I
R=
2
V/
R=IV
P : power (Watts)
I : current (Amps)
R : resistance (W)
V : voltage (Volts)
Remember: Power is energy per time (P=E/t)
CIRCUITS

PARALLEL
 current has multiple
paths to follow

1/Requivalent = 1/R1 + 1/R2
voltage is the same
Vtotal = V1 = V2
 current adds for each
Itotal = I1 + I2

http://www.regentsprep.org/Regents/physics/phys03/bparcir/default.htm

SERIES
 current has only one
path to follow
 Requivalent = R1 + R2
 voltage adds for each
Vtotal = V1 + V2
 current is the same
Itotal = I1 = I2
http://www.regentsprep.org/Regents/physics/phys03/bsercir/default.htm
Pre-Class Tuesday 10-30-12

What is Ohm’s Law?
Producing Light
Incandescent


A piece of metal
in a closed space
is heated by
electricity
Filament
(glowing metal)
made of tungsten
Fluorescent

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An electric
current is sent
through a gas
(mercury and
argon) in a closed
space
Similar to
lightning
All artificial producers of light follow one of
these two methods, except for a laser or LED.
Lightning (and electrical) Safety
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Lightning
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Attracted to tall, pointy conductors
Safest place: car
Beware of storing charge accidently
Always switch off the breaker before working on wires in the
home.
Ohm’s Lab
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Materials
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1.5 V battery
4 sets of wires
Ammeter
Voltmeter
2 light bulbs
Switch
Objectives
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To explore how to wire a circuit correctly
To use Ohm’s Law in calculations
To practice drawing schematics
Procedures
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Determine the voltage of your battery. Record its values.
Connect the 1.5 V battery to the light bulb and switch. Measure the
current through the circuit (ammeter) and the voltage drop across the
light bulb (voltmeter). Record their values.
Draw a schematic of step 2.
Add another light bulb to the circuit (series). Measure the current through
the circuit and the voltage drop across both light bulbs. Record their
values.
Draw a schematic for step 4.
Repeat steps 4 and 5 with the light bulbs being in parallel.
The 6 V battery provides too much energy for the light bulbs for an
extended time. Using the resistors provided and the knowledge gained
already, make a stable circuit to provide a bright, long-lasting bulb.
Draw a schematic for step 7.
Measure the current through and the voltage drop across each resistor
and light bulb. Record their values.
Find the resistance of each light bulb and resistor for every step. Record
their values.
Table
Step
V1 ( ) V2 ( ) I1 ( ) I2 ( ) R1 ( ) R2 ( )
2
4
6
9
Questions:
1) What happens to the current in a series circuit? Parallel?
2) What happens to the voltage in a series circuit? Parallel?
Pre-Class Friday 11-2-12

There are four ways to change the internal resistance
of a wire. Give me one of them.
Pre-class Monday 11-5-12
A 1.5 Volt battery is connected to a small light
bulb with a resistance of 9 W. What is the
current in and power used by the bulb?
I = V/R = 1.5 / 9 = 1/6 or 0.167 Amps
P = I V = 0.167 x 1.5 = 0.25 Watts
Getting started in Solid Edge
Solid Edge Fundamentals ST4
Start  Programs  Solid Edge V20
Solid Edge Environments:
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Part
Sheet Metal Part
Weldment
Assembly
Draft
Schematics in Solid Edge ST4
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Solid Edge is a 2D and 3D Computer Aided Design
(CAD) program.
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Solid Edge allows you to take hand sketches and turn
them into professional drawings.
The draft environment will produce 2D drawings.
Using the Ohm’s Law Lab from this week, draw one
of the schematics in Solid Edge and show it to me.
Each person in the group has to draw one.
I will check your name off the paper when you have
completed the schematic. Be sure to turn in the
paper when everyone is done.
Pre-class Monday 4-2-12
Write: “Reviewing for written test”
or “Finishing performance test”.
Pre-class Tuesday 4x3=12
Write: “Written and performance
test today.”
Pre-class Thursday 10-23-08
Guest Speaker: Adam Panagos
Pre-Class Friday 03-14-08
If p were a shape, what shape would it
be?
Happy p Day!
Pre-Class Tuesday 10-11-11
Today’s date is a binary number. What would
be the decimal (base 10) value for it?