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.
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