TABLE OF CONTENTS Darren Ashby
Tim Williams
Whatever you do with electronics, you are going to need power to accomplish it. It will be useful to understand the basics of power supplies, as you are nearly guaranteed to deal with them at some point in your career.
Most devices today want to keep the voltage constant. This means that current can vary as needed. In the world of power, particularly as it relates to the ubiquitous IC, it often seems that you never have the exact voltage you want.
A huge number of products run off of 120 VAC out of a wall socket. Another huge group runs off of batteries that are charged from those wall sockets, and another significant number runs off of batteries that you can buy by the caseload at any supermart. Just ask yourself, how many batteries did you buy last Christmas?
The problem is that most ICs these days want 5, 3.3, or even 1.5V DC. This is nowhere near 120V, and definitely not AC! Enter the power supply. They come in two flavors, linear and switcher.
AC rules! It is everywhere. It may seem like the world runs on batteries these days, but AC still has the majority foothold. Back when Edison and Tesla argued over what type of electrical power distribution we should have, I'll bet they had no idea of the type of integration that would occur in the world...
