Page 1 1 Lecture 4, Slide 1 EECS40, Fall 2003 Prof. King Announcements • Visit the class website to see updated TA section assignments http://www-inst.eecs.berkeley.edu/~ee40 • Lab section 13 (Mondays 6-9PM) is cancelled • Prof. King’s Office Hour tomorrow (Thu. 9/4) will be held from 8:30AM-9:30AM • HW assignments will NOT be accepted in class. Turn in your assignments BEFORE class on Friday in 240 Cory. Lecture 4, Slide 2 EECS40, Fall 2003 Prof. King Lecture #4 OUTLINE • Circuit element I-V characteristics • Construction of a circuit model • Kirchhoff’s laws – a closer look Reading (Finish Chapter 2) Page 2 1 Lecture 4, Slide 1 EECS40, Fall 2003 Prof. King Announcements • Visit the class website to see updated TA section assignments http://www-inst.eecs.berkeley.edu/~ee40 • Lab section 13 (Mondays 6-9PM) is cancelled • Prof. King’s Office Hour tomorrow (Thu. 9/4) will be held from 8:30AM-9:30AM • HW assignments will NOT be accepted in class. Turn in your assignments BEFORE class on Friday in 240 Cory. Lecture 4, Slide 2 EECS40, Fall 2003 Prof. King Lecture #4 OUTLINE • Circuit element I-V characteristics • Construction of a circuit model • Kirchhoff’s laws – a closer look Reading (Finish Chapter 2) 2 Lecture 4, Slide 3 EECS40, Fall 2003 Prof. King Current vs. Voltage (I-V) Characteristic • Voltage sources, current sources, and resistors can be described by plotting the current (i) as a function of the voltage (v) • Later, we will see that the I-V characteristic of any circuit consisting only of sources and resistors is a straight line. + v _ i Lecture 4, Slide 4 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Voltage Source 1. Plot the I-V characteristic for v s > 0. For what values of i does the source absorb power? For what values of i does the source release power? 2. Repeat (1) for v s < 0. 3. What is the I-V characteristic for an ideal wire? + _ v s i i + v _ v Page 3 1 Lecture 4, Slide 1 EECS40, Fall 2003 Prof. King Announcements • Visit the class website to see updated TA section assignments http://www-inst.eecs.berkeley.edu/~ee40 • Lab section 13 (Mondays 6-9PM) is cancelled • Prof. King’s Office Hour tomorrow (Thu. 9/4) will be held from 8:30AM-9:30AM • HW assignments will NOT be accepted in class. Turn in your assignments BEFORE class on Friday in 240 Cory. Lecture 4, Slide 2 EECS40, Fall 2003 Prof. King Lecture #4 OUTLINE • Circuit element I-V characteristics • Construction of a circuit model • Kirchhoff’s laws – a closer look Reading (Finish Chapter 2) 2 Lecture 4, Slide 3 EECS40, Fall 2003 Prof. King Current vs. Voltage (I-V) Characteristic • Voltage sources, current sources, and resistors can be described by plotting the current (i) as a function of the voltage (v) • Later, we will see that the I-V characteristic of any circuit consisting only of sources and resistors is a straight line. + v _ i Lecture 4, Slide 4 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Voltage Source 1. Plot the I-V characteristic for v s > 0. For what values of i does the source absorb power? For what values of i does the source release power? 2. Repeat (1) for v s < 0. 3. What is the I-V characteristic for an ideal wire? + _ v s i i + v _ v 3 Lecture 4, Slide 5 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Current Source 1. Plot the I-V characteristic for i s > 0. For what values of v does the source absorb power? For what values of v does the source release power? 2. Repeat (1) for i s < 0. 3. What is the I-V characteristic for an open circuit? i i + v _ v i s Lecture 4, Slide 6 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Resistor 1. Plot the I-V characteristic for R = 1 k? . What is the slope? i i + v _ v R Page 4 1 Lecture 4, Slide 1 EECS40, Fall 2003 Prof. King Announcements • Visit the class website to see updated TA section assignments http://www-inst.eecs.berkeley.edu/~ee40 • Lab section 13 (Mondays 6-9PM) is cancelled • Prof. King’s Office Hour tomorrow (Thu. 9/4) will be held from 8:30AM-9:30AM • HW assignments will NOT be accepted in class. Turn in your assignments BEFORE class on Friday in 240 Cory. Lecture 4, Slide 2 EECS40, Fall 2003 Prof. King Lecture #4 OUTLINE • Circuit element I-V characteristics • Construction of a circuit model • Kirchhoff’s laws – a closer look Reading (Finish Chapter 2) 2 Lecture 4, Slide 3 EECS40, Fall 2003 Prof. King Current vs. Voltage (I-V) Characteristic • Voltage sources, current sources, and resistors can be described by plotting the current (i) as a function of the voltage (v) • Later, we will see that the I-V characteristic of any circuit consisting only of sources and resistors is a straight line. + v _ i Lecture 4, Slide 4 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Voltage Source 1. Plot the I-V characteristic for v s > 0. For what values of i does the source absorb power? For what values of i does the source release power? 2. Repeat (1) for v s < 0. 3. What is the I-V characteristic for an ideal wire? + _ v s i i + v _ v 3 Lecture 4, Slide 5 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Current Source 1. Plot the I-V characteristic for i s > 0. For what values of v does the source absorb power? For what values of v does the source release power? 2. Repeat (1) for i s < 0. 3. What is the I-V characteristic for an open circuit? i i + v _ v i s Lecture 4, Slide 6 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Resistor 1. Plot the I-V characteristic for R = 1 k? . What is the slope? i i + v _ v R 4 Lecture 4, Slide 7 EECS40, Fall 2003 Prof. King “Lumped Element” Circuit Modeling (Model = representation of a real system which simplifies analysis) • In circuit analysis, important characteristics are grouped together in “lumps” (separate circuit elements) connected by perfect conductors (“wires”) • An electrical system can be modeled by an electric circuit (combination of paths, each containing 1 or more circuit elements) if ? = c/f >> physical dimensions of system Distance travelled by a particle travelling at the speed of light in one period Example: f = 60 Hz ? = 3 x 10 8 m/s / 60 = 5 x 10 6 m Lecture 4, Slide 8 EECS40, Fall 2003 Prof. King Construction of a Circuit Model • The electrical behavior of each physical component is of primary interest. • We need to account for undesired as well as desired electrical effects. • Simplifying assumptions should be made wherever reasonable. Page 5 1 Lecture 4, Slide 1 EECS40, Fall 2003 Prof. King Announcements • Visit the class website to see updated TA section assignments http://www-inst.eecs.berkeley.edu/~ee40 • Lab section 13 (Mondays 6-9PM) is cancelled • Prof. King’s Office Hour tomorrow (Thu. 9/4) will be held from 8:30AM-9:30AM • HW assignments will NOT be accepted in class. Turn in your assignments BEFORE class on Friday in 240 Cory. Lecture 4, Slide 2 EECS40, Fall 2003 Prof. King Lecture #4 OUTLINE • Circuit element I-V characteristics • Construction of a circuit model • Kirchhoff’s laws – a closer look Reading (Finish Chapter 2) 2 Lecture 4, Slide 3 EECS40, Fall 2003 Prof. King Current vs. Voltage (I-V) Characteristic • Voltage sources, current sources, and resistors can be described by plotting the current (i) as a function of the voltage (v) • Later, we will see that the I-V characteristic of any circuit consisting only of sources and resistors is a straight line. + v _ i Lecture 4, Slide 4 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Voltage Source 1. Plot the I-V characteristic for v s > 0. For what values of i does the source absorb power? For what values of i does the source release power? 2. Repeat (1) for v s < 0. 3. What is the I-V characteristic for an ideal wire? + _ v s i i + v _ v 3 Lecture 4, Slide 5 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Current Source 1. Plot the I-V characteristic for i s > 0. For what values of v does the source absorb power? For what values of v does the source release power? 2. Repeat (1) for i s < 0. 3. What is the I-V characteristic for an open circuit? i i + v _ v i s Lecture 4, Slide 6 EECS40, Fall 2003 Prof. King I-V Characteristic of Ideal Resistor 1. Plot the I-V characteristic for R = 1 k? . What is the slope? i i + v _ v R 4 Lecture 4, Slide 7 EECS40, Fall 2003 Prof. King “Lumped Element” Circuit Modeling (Model = representation of a real system which simplifies analysis) • In circuit analysis, important characteristics are grouped together in “lumps” (separate circuit elements) connected by perfect conductors (“wires”) • An electrical system can be modeled by an electric circuit (combination of paths, each containing 1 or more circuit elements) if ? = c/f >> physical dimensions of system Distance travelled by a particle travelling at the speed of light in one period Example: f = 60 Hz ? = 3 x 10 8 m/s / 60 = 5 x 10 6 m Lecture 4, Slide 8 EECS40, Fall 2003 Prof. King Construction of a Circuit Model • The electrical behavior of each physical component is of primary interest. • We need to account for undesired as well as desired electrical effects. • Simplifying assumptions should be made wherever reasonable. 5 Lecture 4, Slide 9 EECS40, Fall 2003 Prof. King Terminology: Nodes and Branches Node: A point where two or more circuit elements are connected – entire wire Branch: A path that connects two nodes Lecture 4, Slide 10 EECS40, Fall 2003 Prof. King Notation: Node and Branch Voltages • Use one node as the reference (the “common” or “ground” node) – label it with a symbol • The voltage drop from node x to the reference node is called the node voltage v x . • The voltage across a circuit element is defined as the difference between the node voltages at its terminals Example: + _ v s + v a _ + v b _ ab c R 1 R 2 –v 1 +Read More

Offer running on EduRev: __Apply code STAYHOME200__ to get INR 200 off on our premium plan EduRev Infinity!