Digital
electronics comes next. Digital circuits work with only two voltage states, high
(e.g., 5 V) or low (e.g., 0 V). The reason for having only two voltage states
has to do with the ease of data (numbers, symbols, control information)
processing and storage. The process of encoding information into signals that
digital circuits can use involves combining bits (1’s and 0’s, equivalent
to high and low voltages) into discrete-meaning “words.” The designer dictates what these
words will mean to a specific circuit. Unlike analog electronics, digital
electronics uses a whole new set of components, which at the heart are all
integrated in form. A huge number of specialized ICs are used in digital
electronics. Some of these ICs are designed to perform logical operations on
input information, others are designed to count, while still others are
designed to store information that can be retrieved later on. Digital ICs
include logic gates, flip-flops, shift registers, counters, memories,
processors, and the like. Digital circuits are what give electrical
gadgets “brains.” In order for digital
circuits to interact with analog circuits, special analog-to-digital (A/D)
conversion circuits (read more about this subject by going to http://actodc-converter.info) are needed to convert analog signals into
special strings of 1’s and 0’s. Likewise, digital-to-analog conversion circuits
are used to convert strings of 1’s and 0’s into analog signals.
Throughout
your study of electronics, you will learn about various input-output (I/O)
devices (transducers). Input devices convert physical signals, such as sound, light,
and pressure, into electrical signals that circuits can use. These devices
include microphones, phototransistors, switches, keyboards, thermistors, strain
gauges, generators, and antennas. Output devices convert electrical signals
into physical signals.
Output
devices include lamps, LED and LCD displays, speakers, buzzers, motors (dc,
servo, stepper), solenoids, and antennas. It is these I/O devices that allow humans
and circuits to communicate with one another.
And finally
comes the construction/testing phase. This involves learning to read schematic
diagrams, constructing circuit prototypes using breadboards, testing prototypes
(using multimeters, oscilloscopes, and logic probes), revising prototypes (if needed),
and constructing final circuits using various tools and special circuit boards.
Read the 3rd
part – Click here.
