Power Sources: The Good, the Bad, and the Ugly

摘要

Before you plug in that power source, try to answer four important questions: 1. What is the current requirement for your application? 2. Given the voltage you are going to use, what is the power dissipation you expect, and can you handle this? 3. What is the unloaded output voltage and source resistance of the power source you plan to use, and what will be the loaded output voltage? Is this adequate? 4. How much ripple noise is there on your power supply and is this okay in your applications? With the simple measurement and analysis techniques offered here, you will be able to answer these questions and eliminate one common source of problems in your next project.