Electronic principles - Chapter 1 doc

MALVINO Electronic PRINCIPLES SIXTH EDITION Chapter 1 Introduction 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 Q 1 Q 2 d 2 {does not require verification} {verified by experiment} R L10 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 R L10 V A real voltage source has a series resistance. This model is called the the second approximation. R S 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. R L 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 R L 1 A I R L < 1 Ampere A real current source has a shunt resistance. R S 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. 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 kΩ 4 kΩ 3 kΩ R L 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 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 MΩ. 6 kΩ 4 kΩ 3 kΩ R L 72 V 6 kΩ (R TH ) R L 24 V (V TH ) The original circuit The Thevenin equivalent circuit [...]... two 10 Ω resistors form a stiff voltage divider? 10 Ω 12 V 10 0 kΩ 10 Ω Why? 10 0 kΩ A troubleshooting example: What are the expected voltages in this circuit? 10 Ω 12 V 10 0 kΩ 10 Ω 10 0 kΩ A troubleshooting example: What are some causes for this voltage being too high? 10 Ω 12 V 10 0 kΩ 10 Ω 10 0 kΩ V A troubleshooting example: What are some causes for this voltage being too low? 10 Ω 12 V 10 0 kΩ 10 Ω 10 0 . = 0/0 {indeterminate} 10 Ω 10 0 kΩ 10 Ω 12 V 10 0 kΩ A troubleshooting example: Do the two 10 Ω resistors form a stiff voltage divider? Why? 10 Ω 10 0 kΩ 10 Ω 12 V 10 0 kΩ A troubleshooting. expected voltages in this circuit? 10 Ω 10 0 kΩ 10 Ω 12 V 10 0 kΩ A troubleshooting example: What are some causes for this voltage being too high? V 10 Ω 10 0 kΩ 10 Ω 12 V 10 0 kΩ A troubleshooting example: What. MALVINO Electronic PRINCIPLES SIXTH EDITION Chapter 1 Introduction Three kinds of formulas The definition: The law: The derivation: Invented