Page 49 - Understanding Automotive Electronics

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2 THE SYSTEMS APPROACH TO CONTROL AND INSTRUMENTATION

Figure 2.4
Sampling of a Continuous Variable

of a continuous quantity might be {0.9, 1.1, 1.6, 2.3, 1.5, 1.2, . . .}. However,
computers don’t use decimal number systems since there is no practical way to
represent decimal digits. Rather, computers use a binary number system that is
based on 2 rather than 10. In a binary number system, each numerical value is
represented by a combination of ones or zeros. For example, the decimal
number 11 is represented by 1011. This system will be described in greater
detail in Chapter 3, but for the present, it is sufficient to understand that each
sample is converted to a binary number in the form of combinations of one or
zero. Chapter 3 will explain that this binary system is appropriate for a
computer, in which ones and zeros correspond to transistors that are either “on”
or “off,” respectively. By having a sufficient number of transistors, it is possible
to represent any possible numerical value.

36 UNDERSTANDING AUTOMOTIVE ELECTRONICS