ECE 1270 Introduction to Electric Circuits Suketu Naik

0ECE 1270: Introduction to Electric Circuits

Lecture 4:

Equivalent

Networks

Chapter 3

Simple Resistive

Circuits

ECE 1270 Introduction to Electric Circuits Suketu Naik

1Resistors in Series

Req=equivalent

resistance

ECE 1270 Introduction to Electric Circuits Suketu Naik

2Resistors in Series

Req=equivalent resistance

4321 RRRRReq

ECE 1270 Introduction to Electric Circuits Suketu Naik

3Resistors in Parallel

Req=equivalent resistance

4321

11111

RRRRReq

ECE 1270 Introduction to Electric Circuits Suketu Naik

4Example 3.1: Find is, i1, i2

ECE 1270 Introduction to Electric Circuits Suketu Naik

5AP 3.1

(a) Find the voltage v

(b) power delivered the to the circuit the current source

(c) power disspated in the 10 Ω resistor

ECE 1270 Introduction to Electric Circuits Suketu Naik

6Voltage Divider Circuit

ECE 1270 Introduction to Electric Circuits Suketu Naik

7Voltage Divider Examples

ECE 1270 Introduction to Electric Circuits Suketu Naik

8Current Divider Circuit

ECE 1270 Introduction to Electric Circuits Suketu Naik

9Current Divider Examples

Example 3.3: Find power dissipated in 6 Ω resistor

AP 3.3: Find R such that 4 A will flow through 80 Ω resistor

ECE 1270 Introduction to Electric Circuits Suketu Naik

10How do you measure Current and Voltage in a circuit?

Use Ammeter to measure the current: connect it in series

Use Voltmeter to measure the voltage: connect it in parallel

ECE 1270 Introduction to Electric Circuits Suketu Naik

11Delta-to-Y (Pi-to-Tee) Equivalent Circuits

Delta or Pi Configuration

Y or Tee Configuration

ECE 1270 Introduction to Electric Circuits Suketu Naik

12Delta-to-Y Transformation

Example 3.7: Find power supplied by 40V source

Wheatstone Bridge

ECE 1270 Introduction to Electric Circuits Suketu Naik

13How do you measure Resistance?

When the bridge is balanced, ig=0 and i1=i3 and i2=ixThen, Rx/R3=R2/R1

If R2=R1 then Rx=R3

Wheatstone Bridge

ECE 1270 Introduction to Electric Circuits Suketu Naik

14Y-to-Delta Transformation

AP3.8: Use Y-to-Delta transformation to find v