HW29%20solution

# HW29%20solution - x which can be done using the following...

This preview shows pages 1–2. Sign up to view the full content.

ECE 201 Spring 2010 Homework 29 Solutions Problem 40 (a) The following diFerential equation can be written using KCL at the inverting terminal of the op amp and using the virtual ground concept, v s ( t ) R 1 + v out ( t ) R 2 + C dv out ( t ) dt =0 v s ( t )= - 100 u ( t ) = - 100 ,t 0 v out ( t )= 100 R 2 R 1 (1 - e - t/R 2 C ) = 400(1 - e - 2 t ) mV, t 0 Problem not from the book If we denote the voltage at the non-inverting terminal of the op amp as v L ( t ), then using the virtual ground concept, the output voltage is given by V out ( t ) = 10 v L ( t ). Also, v L ( t )= V IN ( t ) - 1000 i L ( t ). The problem then reduces to ±nding i L ( t ). Due to the square wave shape of V IN ( t ), the graph for i L ( t ) will also be periodic with maximum and minimum values of x and - x (say). The task is to ±nd the value of

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: x , which can be done using the following equation, i L ( t ) = i L ( ∞ ) + [ i L (0)-i L ( ∞ )] e-t/τ τ = L R = 2 μs x = 2 × 10-4 + [-x-2 × 10-4 ] e-. 5 ⇒ x = 0 . 489 × 10-4 1 The plot of V out ( t ) for 0 ≤ t ≤ 2 μs is drawn below. Note that V out ( t ) will be periodic with period 2 μs . 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 x 10 − 6 − 2.5 − 2 − 1.5 − 1 − 0.5 0.5 1 1.5 2 2.5 t(seconds) V out (t)(Volts) Plot of V out (t) for 0<=t<=2us. Note that it is periodic with period 2us 2...
View Full Document

## This note was uploaded on 01/22/2012 for the course IE 370 taught by Professor Chunghorng,r during the Spring '08 term at Purdue.

### Page1 / 2

HW29%20solution - x which can be done using the following...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online