History of Computers - Vacuum Tubes
This page created by: Max Susman
Vacuum tubes were indirectly invented by Henry Woodward in 1874, who was the inventor of the first "light bulb". A few years later the patent was purchase by Thomas Edison, who worked on improving Woodward's invention. Essentially the first diode, vacuum tubes were critical to the development of electrical technology.
Contents
Overview
|
| A Vacuum Tube |
What is a Vacuum Tube?
A vacuum tube is a device used to amplify, switch, modify, or create an electrical signal by controlling the movement of electrons in a low-pressure space. Vacuum tubes were widely distributed when they were beginning to be used in devices like radios, speakers, and televisions; however, they were also used in the primitive models of computers before diodes and transistors became the new technology. This type of vacuum tube is known as a diode, which was developed by John A. Fleming[1].
Use of Vacuum Tubes in Computers
Vacuum tubes were invented the same time the light bulb was invented by Thomas Edison and worked very similar to light bulbs. It's purpose was to act like an amplifier and a switch. Without any moving parts, vacuum tubes could take very weak signals and make the signal stronger. Vacuum tubes could also stop and start the flow of electricity instantly, which allows the a computer to run much faster than using manual switches. These two properties made the ENIAC computer possible[2]. There were a few problems with using vacuum tubes in computers, which included: computers required thousands of tubes, approx. Over 10,000 in the ENIAC alone, and the tubes would frequently overheat, sharing many characteristics with the light bulb.
Significance to the History of Computers
Vacuum tubes were significant to the history of computers because by cascading these switches, complicated logic circuits could be created. This is significant because it took the need for manual switches out of computers, and replaced it with an automated way of starting, stopping, and redirecting current. The invention of vacuum tubes eventually led to the development of smaller, more efficient three pronged transistors[3].
Links
www.crews.org; en.wikipedia.org; nobelprize.org Assorted Vacuum Tubes
