How Electronic Gates Work ?
Understanding how electronic gates work involves learning details of the two parts of the phrase – “electronic” and “gates.” The first word implies that electrons move through a circuit, which is the key element of working with electricity in modern equipment. The second word, “gates” brings to mind the more common gate – a device that opens and closes to allow passage through a fence, for example.
Electronic gates are considered the key element in computers for business and personal use. These gates allow computers to make “decisions,” so to speak. As defined by school texts and electronic-training materials gates are tiny switches that can receive several input signals and produce one input, for a particular purpose.
Gates in electronic circuits operate on the amount of voltage that passes through the system. Two separate conditions are needed to make electronic gates work in sensitive equipment – high voltage and low voltage. These are also referred to as “true” and “false” to distinguish between the desired input/output and the input/output action that is not desired at that particular time.
In the world of computer operation electronic gates are a key element of decision-making tasks. To get a better handle on this idea we should take a closer look at Boolean Logic, described as “a complete system for logical operations.” (Wikipedia)
Boolean Logic is named for George Boole, the man who described in detail “an algebraic system of logic in the mid-19th century.” In later years, other mathematicians, scientists and electronics experts described how “electric circuits with relays were a model for Boolean logic.” (Wikipedia)
At the heart of this concept are bits that have two and only two possible values. These are the true and false or off and on mentioned earlier. Electronic gates come in a variety of designs. For example, the “and” gate permits or allows a “true” output (at high voltage) if all the input signals are “true.” In contrast, “or” gates permit or allow a “true” output at high voltage if one of the input signals is true. If at least one input is not true then the gate will allow or release a low voltage output (low voltage). Other types of electronic gates are “not,” “nand” and “nor.”
In some written descriptions of electronic gates these essential computer-system elements have been described as “traffic policemen.” This is an accurate way to envision the task that electronic gates perform in the world of digital electronics. Computers cannot actually make decisions, of course. But with proper design these gates do direct traffic in a computer system, moving bits of information in the correct direction and stopping information that, if permitted to pass, would produce an incorrect result.
In 21st century electronics and computer systems, gates still operate on the same Boolean logic concept that started us on this path decades ago. But technology has improved from mechanical relays to vacuum tubes and then to transistors. Eventually the gate concept was applied to integrated circuits that didn’t have the many distinct parts of earlier electrical circuits.
Category: Technology