1. Introduction to Electrical & Computer Engineering Circuit Elements 1 Dr. Cynthia Furse University of Utah

2. Circuit Elements (2) Voltage & Current Sources – Dependent / Independent – Ideal / Non-Ideal – i-v curves Open, Short Circuits Switches – Wiring Three-Way switches 2

3. Ideal Voltage and Current Sources 3 vs - - + is

4. Non-Ideal Voltage & Current Sources 4 vs - - I + Rs is - Rs

5. Internal Resistance 5 Energizer Tech Bulletin Battery Internal Resistance ver 1.1.0, Dec 05 http://data.energizer.com/PDFs/BatteryIR.pdf

6. How does this affect you? 6 vs - - is + Rs Rload = 1Ω

7. This is (one reason) WHY our batteries went dead so fast in Antarctica! 7

8. I-V Curves used for diagnosis, design, etc. 8 Voltage (V) Current (I) V = I R 1V 1mA R=1kΩ 0.5mAR=2kΩ V R I R=0 R= ∞

9. I-V Curves for LED (Vf is where light turns on) 9 http://www.electronics-tutorials.ws/diode/diode_8.html

10. Open Circuit R = ∞ I = 0 Short Circuit R = 0 I = ∞ 10 http://completeelectrical.biz/electricity-101-types-of-circuits/

11. Fuse / Circuit Breaker I ≠ ∞ 11 http://homerepair.answers.com/electrical/online-diagrams-of-residential-electrical-power- panels

12. Switches 12 Single Pole Single Throw (SPST) Single Pole Double Throw (SPDT) And more…

13. Three-Way Light Switch Wiring 13

14. Conclusion Circuit Elements Voltage & Current Sources – Dependent / Independent – Ideal / Non-Ideal – i-v curves Open, Short Circuits Switches – Wiring Three-Way switches 14

15. Sunflowers & Thunderheads Blackhawk Trail Payson Canyon, Utah 15