Application of Transistors

Transistors are an integral part of the modern world.

The transistor was perhaps the most important invention of the 20th century. This is because, though it is a relatively simple device, it led the way to a whole series of other inventions that have come to shape the modern world as we know it.

History

Before transistors came along, engineers used vacuum tubes to create and control electrical signals. The first computers used these bulky devices, as did the first radios and televisions. In 1947, though, Bell Labs produced the first working transistor, which could function the same as a vacuum tube but without the same limitations. Since then, transistors have continually evolved, becoming ever smaller and more complex. The most important breakthrough in transistor technology, though, was the invention of the integrated circuit in 1961. This led to a rapid expansion of transistor capabilities, causing them to have an almost ubiquitous status in consumer electronics.

Significance

With the advent of the transistor, computers could suddenly perform the same functions while occupying a fraction of the space they did previously. In addition, manufacturers could mass-produce transistors at a significantly lower price than vacuum tubes, which in turn reduced the prices and expanded the availability of the electronics for which these components were made.

Function

Transistors can act as switches or as amplifiers. As switches, they can convert the characteristics of an electric current into what a specific device requires, or they can act as "logic gates" for computers, switching on and off to perform binary logic operations. As amplifiers, they provide the necessary electric signals for radios, televisions, mobile phones and other communications devices. They do this by exhibiting a property called "gain," in which they take a faint signal and use electricity from a separate source to make that signal stronger while maintaining the same frequency patterns.

Misconceptions

Some people think that the switch from vacuum tubes to transistors to integrated circuits is an example of three different types of technology, with transistors and integrated circuits each obliterating the necessity of its predecessor. In truth, though, integrated circuits are actually just very complex transistors, and manufacturers continue to produce both vacuum tubes and transistors even today.

Benefits

The benefits of transistors over both vacuum tubes and integrated circuits is that they are so cheap to produce. Compared to vacuum tubes, they are also smaller and more durable. Though their simplicity leads to a number of limitations when compared to integrated circuits, it also allows engineers to use them to build circuitry in a much quicker time frame. In addition to that, while integrated circuits are extremely susceptible to electromagnetic pulse (EMP), transistors generally resist its effects. Because of this, military technology that uses integrated circuits often requires extensive shielding, as high levels of EMP come as a result of nuclear explosions. (In the event of all-out war, many machines relying on unshielded integrated circuits will cease functioning.)

References

• NobelPrize: The Transistor
• Porticus: Bell Labs: History of the Transistor
• IEEE Global History Network: The Transistor and Portable Electronics