Before We Begin: Notation

This book was written as an ebook with no intention of it being published in printed form. Unfortunately, not all browsers and eReaders are equipped to handle the type of formatting typically used in a book of this nature. For that reason, some accommodation in the way numbers and symbols are presented using subscripts and superscripts is required. In a typical text dealing with electronics, you are likely to find an equation like the following presented.

Figure 1. An equation with subscripts.

The preceding equation looks as it should, using subscripts, because it is an image. Depending on the browser oreReader, images cannot be reliably inserted inline with the text of the book. For that reason, the equation shown in Figure 1 will be written as: Itotal = I1 + I2 + I3 when appearing as part of the text of this book.

Likewise, the use of scientific notation suffers due to the same limitations involving superscripts. For example, the number shown in the following figure cannot be reliably represented within the text of this book.

Figure 2. One Coulomb expressed in scientific notation.

The value shown in Figure 2 will be shown as either 6.241 x 10^18 or 6.241E18 when the value is not part of a stand alone figure. When expressed as 6.241 x 10^18, the superscripted exponent is indicated by the value following a caret (^). If the value is expressed as 6.241E18, the “E” stands in for “x 10^”. The caret (^) is used to indicate an exponent in other situations as well. For instance, three raised to the second power (three squared) is written as 3^2.

Following convention, when equations are presented in a figure, the multiplication symbol (×) is not used. For instance, if there are two values, “a” and “b”, their product is given as “ab”. This can be confusing when a calculation is being shown as part of the text of this book due to formatting issues. In these cases, all multiplications are explicitly shown by using an asterisk (*). For instance, instead of showing the product of “a” and “b” as “ab”, it is shown as a*b.