Signal original form to a waveform expressed as a current ("I") or a voltage ("V"), or an electromagnetic waveform, for example, an optical signal or radio transmission. Once expressed as an electronic signal, the signal is available for further processing by electrical devices such as electronic amplifiers and electronic filters, and can be transmitted to a remote location by electronic transmitters and received using electronic receivers. In Electrical engineering programs, a class and field of study known as "signals and systems" (S and S) is often seen as the "cut class" for EE careers, and is dreaded by some students as
Timeline of United States inventions (1946–91) polypropylene or polyester film and fiberglass filaments embedded to add high tensile strength. Filament tape was invented in 1946 by Cyrus Woodrow Bemmels. In 1949, it was placed on the market and was an immediate success. 1946 Credit card 1946 Diaper (waterproof) 1947 Transistor In electronics, a transistor is a semiconductor device commonly used to amplify or switch electronic signals. Because the controlled output power can be much larger than the controlling input power, the transistor provides amplification of a signal. The transistor is the fundamental building block of all modern electronic devices, and is used in radio, telephone, computer,