1. Why Take Electrical Engineering?
Like computer literacy, electrical literacy is very important to engineering and everyday life
So many things are powered or controlled by electricity
It is used to communicate by video, wireless, phone or data
So many physical phenomena are measured using transducers (devices that convert between a physical phenomena and an electrical voltage, current or resistance that is easily measured and recorded for analysis)

2. Some Transducers Light bulbs, buzzers, alerting devices
Speed indicators
Strain gauges
pH sensors
Temperature or light sensors
Flow sensors
Electric motors
Sound or movement sensors

3. Problem Solving
EE 188 also develops problem-solving and thinking skills – circuit problems must be solved using reasoning and thought, not just by plugging into formulas

4. Energy Crisis
People are using up cheap, nonrenewable energy sources such as oil and coal
Use of oil and coal produces excess carbon dioxide and global climate change
70% of oil is imported
Dependent on global pricing variations
Impacts our security

5. Renewable Alternatives
Nuclear energy
Atmospherically clean
Dangerous
Nuclear waste problems
Wind energy
Clean but unsightly
Not dependable – needs storage capability
Not abundant where needed most

6. Renewable Alternatives
Solar
More expensive
Not dependable – needs storage capability
Geothermal and Hydroelectric
Environmentally sensitive
Limited resources

7. Transportation Alternatives
Plug-in electric gasoline hybrids
Biofueled vehicles
Natural gas-powered vehicles
Hydrogen-powered vehicles
Fuel cell-powered vehicles

8. Plug-In Electric Hybrids
Potential Barriers?

9. Where Does Electricity Come From?
We buy it from power plants
We can generate it ourselves
Diesel or gasoline generators
Generated in our car
Generated by home solar or wind power
We can get it from batteries
Sometimes we get it when we don’t want it
Lightning
Static

10. What is the main fuel used to generate electricity in the US?
 Natural Gas
 Oil
 Hydroelectric
 Nuclear
 Coal
 Wind, Solar, Biomass and Geothermal
Put a one by the fuel most used,
a 2 by the next most used, etc.

11. Fuels Used to Generate Electricity
#1 Coal is used to generate 49% of the electricity in the U.S.

12. Fuels Used to Generate Electricity
#2 Natural gas is used to generate 20% of the electricity in the U.S.

13. Fuels Used to Generate Electricity
#3 Nuclear is used to generate 19.4% of the electricity in the U.S.

14. Fuels Used to Generate Electricity
#4 Hydroelectric is used to generate 7% of the electricity in the U.S.

15. Fuels Used to Generate Electricity
#5 Other Renewables account for 2.4%
Wind
Solar
Biomass
Geothermal

16. Wind Power

17. Solar Photovoltaics

18. Solar Parabolic Trough
A trough can focus the sun at 30 to 100 times its normal intensity
to heat liquid in the receiver pipe to over 400 degrees Celsius.

19. Solar Dish and Engine
A solar dish concentrates the sun at a factor of 2000 achieving
temperatures of 750 C to run an engine which turns a generator.

20. Fuels Used to Generate Electricity
#6 Petroleum is used to generate 1.6% of the electricity in the U.S.

21. Fuel Usage Pie Chart (2006)

22. Energy Usage

23. Electricity Cost Chart (2006)

24. How does Electricity Get to Us?
Wires connect the power plants to the users via the power grid.
Long distances are covered by wires carrying hundreds of thousands of volts
Same power delivered by half the current and twice the voltage
Saves money on wire (typically 40mm in diameter)
Saves money on losses due to resistance in the wire

25. Power Grid

26. Industrial Power
Industrial plants use three phase power (480v) to run most large machinery
They run small machines, lights, computers on single phase power (120/240v)

27. Residential and Commercial
Residential and commercial customers use single phase power – 120 volts for most uses or 240 volts for high power appliances
Transformers are used to reduce the high voltages on the power lines to the lower voltages needed

28. AC and DC Power
Most power generated is Alternating Current (AC) power where the current and voltage varies sinusoidally with time
Direct Current (DC) power doesn’t vary with time
Most consumer products use both AC and DC

29. DC Power DC power is used to power electronics
DC power is easier to store (batteries)
DC power is used in mobile applications
DC power is useful when off the power grid
Inverters convert DC to AC

30. AC Power AC power is easier to distribute
Higher voltage and smaller current yields same power distributed
Transformers make it easy to change voltage levels so smaller wire can used
AC is used for most machinery, lights and appliances
Power supplies convert AC to DC

31. Study of Circuits at NAU
EE 188 – DC circuits and AC circuits when at steady state
EE 280 – Transients, frequency response & both digital and analog electronic circuits
EE 380 – Linear and nonlinear electronic circuits, device models and simulation
EE 480 – Advanced Electronics
EE 482 – Intro. to VLSI electronics design