1. ENGS2613 Intro Electrical Science Week 1, Lectures 1 & 2
Read Chapter 1
Problems 1.2, 10, 11
Quiz #1, 27 January

2. Student Engineering Societies
Architecture
Biosystems & Agriculture
Chemical
Civil & Environmental
Electrical & Computer
Industrial
Materials Science
Mechanical & Aerospace
Attend Student Branch Eng Society Meetings & Get < 10 points Extra Credit
Selfie; or Note from Pres, VP, or Sec stating you attended
3, 3, 4 basis

3. Large Scale Systems
Electric Grid

4. Medium Scale System
Death Star

5. Small Scale System
Atomic Scale

6. Tentative Grading 10 x 10 point full period Friday events
#1 on Friday 27 January
2 x 100 point full period Friday Exams
1 x 30 point design problems
1 x 150 point Comprehensive Final
480 points Total
90%, 80%, etc. for A, B, C... Will be curved.

7. Grading
In Class: Quizzes, Events, Tests, Final Exam Closed Book & Notes < 3 pages of "Assistance" Sheets Allowed Calculators Allowed, Smart Phones Not
Ungraded Homework: Assigned most every class Not collected Answers Available Online Payoff: Tests & Quizzes

8. Why work the ungraded Homework problems?
An Analogy: Electrical Science vs. Soccer
Reading text = Reading a book about Soccer
Looking at problem solutions = watching others play soccer
Working the problems = practicing or playing soccer
Friday Events = Exhibition Game
Test = Big Game

9. To succeed in this class...
Show some self-discipline!! Important!! For every hour of class put in 1-2 hours of your own effort.
PROFESSOR'S LAMENT If you put in the time You should do fine. If you don't, You likely won't.

10. Cheating Don’t do it! If caught, expect to get an ‘F!’ for the course.
My idol: Judge Isaac Parker U.S. Court: Western District of Arkansas
a.k.a. “Hanging Judge Parker”

11. Primary Goal Ability to Analyze & Design Simple Electric Circuits
Understand Basic Electrical Concepts
Ability to Analyze & Design Simple Electric Circuits

12. Volts Named after Allesandro Volta 1745 – 1827 Italian Physicist
Invented Electric Battery
Analogy Plumbing System Volts ≈ Water Pressure
Source: Wikipedia

13. Volts Difference twixt top & bottom = 1.5 v [Top is 1.5v higher
Can be +, -, or 0
Measured relative to something
Difference twixt top
& bottom = 1.5 v
[Top is 1.5v higher
than bottom]
Source: Wikipedia

14. Volts By Convention, Earth = 0 volts a.k.a. Earth Ground or Ground
Volts may be a constant value
a.k.a. Volts DC (DC = Direct Current)
Volts may be variable over time
a.k.a. Volts AC (AC = Alternating Current)
Source: Wikipedia

15. Multimeter Example
Voltage Displayed =
Red Lead – Black Lead

16. Multimeter Example
Voltage Displayed =
Red Lead – Black Lead

17. Multimeter Example
Voltage Displayed =
Red Lead – Black Lead

18. Two Batteries in Series
1.5 v
D Cell
Multimeter VDC
= Red Lead – Black Lead
1.5 v
D Cell
= 3 volts

19. Two Batteries in Series
1.5 v
D Cell
Multimeter VDC
= Red Lead – Black Lead
D Cell
1.5 v
= 0 volts

20. Two Batteries in Parallel
Multimeter VDC
= Red Lead – Black Lead
1.5 v
D Cell
1.5 v
D Cell
= 1.5 volts

21. Coulomb Named after Charles-Augustin de Coulomb 1736 – 1806
Source: Wikipedia
Named after Charles-Augustin de Coulomb
1736 – 1806
French Physicist
1780's Investigated Static Charges (Repulsion & Attraction)
Charge on Electron ≡ e ≡ (10-19) Coulombs
1/e = 6.242(1018)
Unit Charge = Charge on 6.242(1018) electrons

22. Amps Named after Andre-Marie Ampere 1775 – 1836 French Physicist
1820's Investigated Relationship Between Electricity & Magnetism
Analogy Plumbing System Amps ≈ Water Flow
Source: Wikipedia

23. Joule Named after James Prescott Joule 1818 - 1889
British Brewer & Physicist
1840 Began investigating energy & power to improve Brewery's Efficiency
Source: Wikipedia

24. Some Definitions Voltage: An Electro-motive Force Amps: Current
Tries to move Electrons around
Amps: Current
Flow of Electrical Charge (Electrons)
Joules: Energy
1 Joule = 1 Volt * 1 Coulomb
Power: Energy per unit Time
1 Watt = 1 Joule/second

25. Current Flow + ↑ Electron Flow (Negative Charge) Safety Tip:
D Cell
↑ Electron Flow
(Negative Charge)
Safety Tip:
Don't Try This At Home -

26. Joules/Second = Watt Named after James Watt 1736 - 1819
Scottish Mechanical Engineer
> 1759 Began investigating efficiency of Steam Engines
Source: Wikipedia

27. Resistors Source: http://www.bcae1.com/resistrs.htm

28. Ohm's Law Named after Georg Ohm 1789 - 1854
German Physicist University Professor
Investigated relationship between voltage & current
Results published in 1827 V = I R
Source: Wikipedia

29. The "feel" Test, Version 1 9 V Battery on Your Tongue
Tongue Resistance ≈ 16,000 Ω
Ohm's Law: I = V/R = 560 μa
Pain Rating
0 = No Pain
1 = Notice When Bored
2 = Uncomfortable, but no big deal
3 = Uncomfortable but Tolerable
4 = Very Uncomfortable & Want it to Stop …
10 = Don't Notice Anything But Pain

30. The "feel" Test, Version 1B 12 V Car Battery on Your Tongue
Tongue Resistance ≈ 16,000 Ω
Ohm's Law: I = V/R = 750 μa
Pain Rating
About Same as 9 V Battery
Safety Tip: Don't Try This at Home!
Can End Up in Hospital if Leads Touch Each Other
Car Battery Max Current >> V Battery Max Current

31. Car Battery Model Ohm's Law says R = V/I = (0.5 V)/(20 A) = 0.025 Ω

32. Car Battery Model Ohm's Law says I = V/R = (12 V)/(0.025 Ω) = 480 A

33. 9V Battery Model Ohm's Law says R = V/I = (0.5 V)/(0.020 A) = 25 Ω
20 mA
R Ω
9 V
8.5 V
Ohm's Law says
R = V/I = (0.5 V)/(0.020 A)
= 25 Ω

34. 9 V Battery Model Ohm's Law says I = V/R = (9 V)/(25 Ω) = 360 mA 25 Ω