(An Unconventional Guide to Computers) Copyright Information
Relays as Electromagnetic Switches |
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| Digital computers are essentially formed by connecting a lot of switches together, where each switch can be considered to be ON or OFF. More importantly, the ON/OFF state of the switches can be modified as required, and combinations of switches can be used to implement primitive logical functions, which can in turn be used to realize more complex logical functions (you'll have to read the book Bebop BYTES Back if you want to know more than this). | One of the earliest forms of switches used in digital computers was the relay, which is formed from a metal bar surrounded by a coil of wire. When current is passed through the coil, the resulting electromagnetic field causes the metal bar to move (a spring is used to return the bar to its original position when the current is removed). The bar can be used to activate switches which can be used to control other devices; for example, to apply current to the coils of other relays, and so it goes ..... | |
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| Relays were eventually superseded by vacuum tubes, which were themselves subsequently replaced by semiconductor switches in the forms of transistors and integrated circuits. | ||
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| These notes are abstracted from the book Bebop BYTES Back (An Unconventional Guide to Computers) Copyright Information |
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