1. MALVINO Electronic PRINCIPLES SIXTH EDITION

2. Chapter 1 Introduction

3. Three kinds of formulas The definition: The law: The derivation: Invented for a new concept Summarizes a relationship that exists in nature Obtained by manipulating other formulas using mathematics C = Q V {defines what capacitance is} Q = CV f = K Q1Q2Q1Q2 d2d2 {does not require verification} {verified by experiment}

4. RLRL 10 V An ideal voltage source maintains a constant output voltage, regardless of the value of R L. The ideal model can be called the first approximation. V R L = 10 Volts

5. RLRL 10 V A real voltage source has a series resistance. This model is called the the second approximation. RSRS V R L < 10 Volts When R L is equal to or greater than 100 times R S, a real voltage source is stiff and the first approximation can be used.

6. RLRL 1 A An ideal current source maintains a constant output current, regardless of the value of R L. The ideal model can be called the first approximation. I R L = 1 Ampere

7. RLRL 1 A I R L < 1 Ampere A real current source has a shunt resistance. RSRS This model is called the the second approximation. When R S is equal to or greater than 100 times R L, a real current source is stiff and the first approximation can be used.

8. Thevenin’s theorem can be used to replace any linear circuit with an equivalent voltage source called V TH and an equivalent resistance called R TH. 6 k  4 k  3 k  RLRL 72 V Remove the load. Calculate or measure V TH across the open terminals. V TH Remove the source.Calculate or measure R TH. R TH

9. The input impedance of a voltmeter should be at least 100 times greater than the Thevenin resistance to avoid loading error. When working with actual circuits, please remember this guideline: DMMs are usually not a problem since they typically have an impedance of 10 M 

10. 6 k  4 k  3 k  RLRL 72 V 6 k  (R TH ) RLRL 24 V (V TH ) The original circuit The Thevenin equivalent circuit

11. Norton’s theorem can be used to replace any linear circuit with an equivalent current source called I N and an equivalent resistance called R N. 6 k  4 k  3 k  RLRL 72 V Short the load to find I N. ININ R N is the same as R TH. RNRN

12. 6 k  4 k  3 k  RLRL 72 V The original circuit The Norton equivalent circuit 6 k  (R N ) RLRL 4 mA (I N )

13. The Norton dual 6 k  (R N ) RLRL 4 mA (I N ) 6 k  (R TH ) RLRL 24 V (V TH ) A Thevenin equivalent circuit R N = R TH I N = V TH R TH

14. Troubleshooting A solder bridge between two lines effectively shorts them together. A cold solder joint is effectively an open circuit. An intermittent trouble is one that appears and disappears (could be a cold solder joint or a loose connection).

15. An open device The current through it is zero. The voltage across it is unknown. V = zero x infinity {indeterminate}

16. A shorted device The voltage across it is zero. The current through it is unknown. I = 0/0 {indeterminate}

17. 10  100 k  10  12 V 100 k  A troubleshooting example: Do the two 10  resistors form a stiff voltage divider? Why?

18. 10  100 k  10  12 V 100 k  A troubleshooting example: What are the expected voltages in this circuit?

19. 10  100 k  10  12 V 100 k  A troubleshooting example: What are some causes for this voltage being too high? V

20. 10  100 k  10  12 V 100 k  A troubleshooting example: What are some causes for this voltage being too low? V