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Technology

How the invention of the transistor shaped modern computing and electronics

A technical retrospective tracks the progression of electronic switches from 19th-century relays and vacuum tubes to semiconductor transistors.

The short version

  • Transistors replaced early mechanical relays and fragile vacuum tubes as the fundamental switching components in electronics.
  • Semiconductor technology enabled massive miniaturization and lower power consumption relative to early computing components.
  • Modern digital electronics rely on billions of transistors per device, compared to the handful used in early radios.

Key facts

  • Electric relays were introduced in 1835 to act as mechanical switches using an electric current to control another current across telegraph lines.[Wired]
  • Vacuum tubes, developed around 1905, enabled variable electronic amplification and early computer logic gates without mechanical moving parts.[Wired]
  • Bell Labs invented the transistor in 1947, addressing the high power usage, fragility, and physical bulk of vacuum tube systems.[Wired]
  • While early portable radios in the 1950s and 1960s functioned on six to 10 transistors, modern smartphone chips like the iPhone 17 Pro incorporate up to 30 billion.[Wired]

Sources