Circuit Theory/Terminology
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[edit] Basic Terminology
There are a few key terms that need to be understood at the beginning of this book, before we can continue. This is only a partial list of all terms that will be used throughout this book, but these key words are important to know before we begin the main narrative of this text.
- Time domain
- The concept of a domain is very important in mathematics, and is also very important in engineering. Depending on what domain you are in, there are different tools and techniques for analyzing circuits. The "Time domain" is simply another way of saying that our circuits change with time, and that the major variable used to describe the system is time.
- Frequency domain
- The frequency domain is a very commonly used method of describing the behavior of a circuit as functions of the frequency of the signals within it. Another name is the "Fourier domain". Other domains that an engineer might encounter are the the "Laplace domain" (or the "s domain"), and the "Z domain".
- Temporal
- Temporal is basically another way of saying "Time Domain". This is opposed to the word "Spectral", which is analogous to the term "Frequency Domain."
- Circuit Response
- Circuits generally have inputs and outputs. In fact, it is safe to say that a circuit isn't useful if it doesn't have one or the other (usually both). The response to a circuit is the relationship between the circuit's input to the circuit's output. The circuit response may be a measure of either current or voltage.
- Steady State
- When something changes in a circuit, there is a certain amount of transition period before a circuit "settles down", and reaches its final value. This final value, when all elements have a constant or periodic behaviour, is known as the steady-state value of the circuit. The circuit response at steady state (when things aren't changing) is also known as the "steady state response".
- Transient Response
- The response that a circuit has before it settles on its steady-state response is known as the transient response.
