Getting Started - AND or OR?
The logic gates allow the computer to actually perform the mathematical operations that allow it to do everything from display a red pixel when it gets the appropriate data from an image file to crunching enormously complex math problems in fractions of a second.
One way to think of a logic gate is as a switch that is turned on or off depending upon logical input received from another device. Computers, microcontrollers and other digital devices are essentially incredibly complex combinations of these devices, which illustrates why computers are sometimes described as being machines that are simply made up of an enormous number of different on and off switches. In logic gates, on and off corresponds to 1 and 0, respectively, which is also described as true or false.
What are Logic Gates?
In the simplest terms, a logic gate is an electronic device that can perform a Boolean function. These can be made out of a variety of different types of components. In today's world, most logic gates are made using transistors and diodes. It is possible, however, to make logic gates out of just about anything, including mechanical devices, optical devices and many other components. Logic gates can also be utilized in theoretical settings, in which case there is no physical device, as detailed by Jaeger in his book Microelectronic Circuit Design from 1997.
Inside a computer, there are hundreds of millions of logic gates working in concert. The memory has logic gates, the microprocessor has an enormous number of logic gates and, quite simply, logic gates are really at the heart of what makes a computer work.
In the simplest terms, logic gates can perform one logical operation and will always output the same number given the same input. In some cases, however, multiple different logic gates can be combined into entirely new logic gates or multiple logic gates can be combined to take up the function of a single, simple logic gate by combining one of the two universal types of logic gates.
What is Pneumatics Used for?
Pneumatics is useful for many different fields today, and you can find pneumatic devices nearly everywhere. The technology is useful in the fields of material handling, robotics, medical science, entertainment, and much more. Pneumatic tubes can carry items long distances. Air brakes on buses and trucks, exercise machines, pressure regulators and sensors, pipe organs, chairs, vacuum pumps, pneumatic tires, power tools, and more use some form of pneumatics today.
History and Development of Logic Gates
If you're an electrical engineer or just have a hobbyist interest in electronics, you're likely well aware of the fact that some of the most exciting developments in electronics occurred during the end of the 19th and beginning of the 20th centuries. The case is the same with logic gates. The first theoretical development that is documented comes from 1886, when Charles Sanders Peirce theorized how circuits could be utilized to carry out logical operations. Vacuum tubes were eventually employed for this exact purpose and, in 1907, Lee De Forest developed an AND logic gate.
Difference between Distinctive Shape and Rectangular Shape
There are two different shapes used to represent logic gates in schematics. The first type is called the distinctive shape. The distinctive shape originated in the military and is a simplified way of representing the function of a logic gate. The rectangular shape is the second shape utilized to represent logic gates in schematics. These use simple rectangles to represent the component, with a symbol on the inside of the rectangle describing its function. The rectangular shapes are more versatile, allowing a wider variety of logic gates to be represented. The distinctive shapes are very easy to read and make it convenient to ascertain the function of a logic gate in a circuit when looking at a schematic diagram.
Universal logic gates, when they are configured to be the equivalent of a different type of logic gate by combining them in various ways, will be represented on schematic diagrams either by the standard symbol for the logic gate that they have been assembled into or by showing each of the various logic gates involved in creating a single component out of a combination of many components.
What types of Logic Gates Exist?
There are numerous different types of logic gates available. The simplest ones perform one logical function. There are also logic gates that are constructions made out of multiple types of simple logic gates, called compound logic gates. In addition to this, there are logic gates that are designed to have more than two types of output, allowing them to be completely removed from a circuit under conditions when their input needs to be ignored by a device. There are also logic gates that are universal, meaning that they can be used to construct any other type of logic gate.
What is an AND Gate?
AND gates are types of logic gates utilized to implement logical conjunction. It will only output a 1 under the condition that both of the inputs are 1s.
Boolean algebra between A & B. An AND will output a 0 unless both of the inputs are 1s.
|
INPUT |
OUTPUT |
|
|
A |
B |
A AND B |
|
0 |
0 |
0 |
|
0 |
1 |
0 |
|
1 |
0 |
0 |
|
1 |
1 |
1 |
What is AND-OR-Invert?
An AND-OR Invert is a type of compound logic gate. It has two levels and consists of a NOR gate preceded by one or more AND gates.
Distinctive Shape: Note that this shape is dependent upon the number of gates used. (Below is an example)
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Rectangular Shape: This shape is dependent upon number of gates used and how they are arranged.
Boolean algebra between A & B
Truth Table:The number of gates affects the truth table for this type of compound gate. The following truth table is for a 2-2 AOI as per Wikitronics.
