1. ELECTRIC CIRCUITS ECSE-2010 Spring 2003 Class 38

2. ASSIGNMENTS DUE Today (Tuesday/Wednesday): Will do Computer Project #5 in Class (CP-5) Activities 38-1, 38-2 (In Class) Thursday: Experiment #9 Report Due Activities 39-1, 39-2 (In Class) Next Monday: Homework #14 Due Experiment #10 Report Due Computer Project #5 Report Due Activity 40-1, Experiment 11 (In Class)

3. FINAL EXAM Wednesday, May 7 8 - 11 am Sage 3303 for All Sections 2-8 1/2 x 11 inch Crib Sheets Laplace Tables Will Be Included with the Final Exam Students with Conflict should Notify Prof. Jennings (jenniw@rpi.edu)

4. REVIEW VI

6. NOTES ON RESONANCE In “real” circuits, often do not have a “pure” Series or pure Parallel situation: Inductors always have R w Elements may not all be in series or parallel Will still have Resonance, but at a slightly different Resonant Frequency May have Multiple Resonances in same Circuit Define Resonance as when X (series-like circuit) or B (parallel-like circuit) => 0 Let’s do a problem => Activity 38-1

7. ACTIVITY 38-1

8. AC PSPICE Now want to simulate AC Circuits using PSpice: AC Sources C’s and L’s Usually want to look at behavior as a function of Frequency: AC Sweep (Schematics).ac Statement (Circuit file)

9. AC PSPICE-CIRCUIT FILE AC Voltage Source: V 1 0 AC 10 AC Current Source: I 0 1 AC 3 Do Not have to designate frequency when specifying source: Do later with.ac statement

10. AC PSPICE-SCHEMATICS AC Voltage Source: Use VAC Doubleclick on VAC Designate Amplitude and Phase AC Current Source with Schematics: Use IAC; Designate same as VAC Do Not have to designate frequency when specifying source: Do later with AC Sweep in Analysis

11. AC PSPICE Capacitors/Inductors: C 1 0 2u L 1 0.1m Start “name” with C or L Connected between nodes 1 and 0 (+, -) C = 2 uF; L =.1mH Do Not need Initial Conditions for AC Steady State Use IC’s when doing Transient Analysis Doubleclick C and L in Schematics to set Values and IC’s

12. AC PSPICE. ac Statement:. ac lin 400 10 16k Perform AC Sweep (Sweep AC frequencies) Perform a linear sweep (will do decade sweeps later) Divide frequency range into 400 points starting frequency = 10 Hz (note: f) ending frequency = 16 kHZ

13. AC PSPICE In Schematics: Doubleclick Set Up Analysis Choose AC Sweep and Doubleclick Choose Type of Sweep Choose Start and End Frequencies Choose Number of Points Remember PSpice uses Frequencies in Hz

14. ACTIVITY 38-2

15. Similar to Activity 38-1: Not a “Pure” Parallel Resonant Circuit Inductor has Winding Resistance Want to see how this affects Resonance Let R w = 10 -9 ~ 0, 2 ohms When R w = 0, f o ~ 8 kHz, Q parallel ~ 10 See what happens when R w = 2 ohms Let’s Practice using Schematics

16. COMPUTER PROJECT 5

17. Circuit is both “Series-like” and “Parallel-like”: Will have both Series and Parallel Resonances Resonances occur at different frequencies Identify by Minimum or Maximum of /Z/ /Z/ is a Minimum at Series Resonance /Z/ is a Maximum at Parallel Resonance

18. COMPUTER PROJECT 5 PSpice wants frequencies in Hertz: Project asks to sweep Must convert = 2 f Plot as function of = f * 6.28 Use Linear X Axis Note: Z in = V in / I in V in = Volts => Y in = I in /1 Siemons