We use signals to carry information from place to place. There are many kinds of signals, but they all share two basic properties.
- The signal must contain some energy and power.
- The signal must have a pattern whose details carry the actual information.
When trying to understand the behaviour of circuits engineers find it useful to consider the signal patterns in terms of complex numbers. Although difficult to understand at first, complex values are a very powerful tool for analyzing fluctuating signals.
Signals take many forms, from people waving flags on hilltops, to students using the World Wide Web! In electronics, signals usually come in two basic forms:
Click on the pictures below to discover information on the signals used in the media shown.