This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: L1 RC-circuits Over the course of five laboratory sessions in ECE 210 you will build a working AM radio receiver that operates on the same principles as commercially available systems. The receiver will consist of relatively simple subsystems examined and discussed in class. We will build the receiver up slowly from its component subsystems, mastering each as it is added. In Lab 1 you will begin your AM receiver project with a study of RC circuits. Although RC circuits are simple, they can perform many functions within a receiver circuit. They are often used as audio filters (the circuitry behind the bass and treble knobs, for example), and as you will see later in this lab, envelope detectors. Because RC circuits are fundamentally important to the AM receiver (and to many other circuits), you will study the characteristics of the capacitor and investigate the transient and steady-state responses of an RC circuit. You will modify this circuit to create the envelope detector for your receiver. Along the way you will learn to generate and measure waveforms with the equipment at your laboratory station. 1 Prelab Circuit analysis is an essential skill for testing your radio as you build it. The prelab exercise reviews techniques that will be important in the laboratory exercise. +- t = 0 v ( t ) V s R = 10 k C = 0 . 1 F +- i ( t ) Figure L1.1: RC circuit for prelab exercise 1. For the circuit of Figure L1.1, calculate the following: a) The RC time constant: 319 L1 RC-circuits b) The voltage v ( t ) across the capacitor 5 ms after the switch is closed, assuming the capacitor is initially uncharged express in terms of V s : c) The initial current i (0 + ) that will flow in the circuit: 2. Suppose you are given an unknown capacitor. Describe an experimental technique that you could use to determine its value: 2 Laboratory exercise Equipment: Function generator, oscilloscope, protoboard, and wires. Components: 10 k resistor, 0.1 F capacitor, and 1N54 diode. 2.1 Generating and Measuring Waveforms In the laboratory, the function generator is the source of waveforms. It can create sinusoids, square waves, triangle waves, and many others over a wide range of amplitudes and frequencies....
View Full Document
This note was uploaded on 04/09/2010 for the course ECE 210 taught by Professor Staff during the Spring '08 term at University of Illinois, Urbana Champaign.
- Spring '08