History

How electricity became electronics

Modern electronics did not appear all at once. It grew from centuries of experiments with electricity and magnetism, followed by practical inventions such as batteries, telegraphs, motors, generators, telephones, radio, vacuum tubes, transistors, and integrated circuits.

This section will follow that story in roughly chronological order while connecting the history to the components and circuits used elsewhere at LearnTronics.

A developing timeline

• Before the electricians — lightning, rubbed amber, static attraction, lodestones, electric fish, and other observations known long before electrical science.
• The world before electrical science — mathematics, logic, natural philosophy, astrology, alchemy, astronomy, and the changing methods that led toward modern experimental science.
• The first electrical machines — Gilbert's early investigations, rotary friction machines, conductivity, insulation, and the growing ability to generate and move static charge deliberately.
• Storing electricity — the Leyden jar — the first practical way to accumulate static charge and release it later; the ancestor of the modern capacitor.
• Animal electricity and the voltaic pile — Galvani's frogs, Volta's challenge, electric fish, and the first practical battery.
• Galvanism and artificial life — cadaver demonstrations, the public fascination with reanimation, and the scientific atmosphere surrounding Frankenstein.
• The battery opens the laboratory — sustained current makes electrolysis, chemical discovery, heating, arcs, and repeatable circuit experiments possible.
• Electricity makes magnetism — current produces a circular magnetic field and leads to coils, solenoids, and electromagnets.
• Magnetism makes electricity — Faraday's induction experiments reveal EMF, generators, and transformer action.
• The telegraph — long wires, relays, electromagnets, switching, and coded signals turn electricity into long-distance communication.
• Electric motors — magnetic force turns electrical energy into continuous mechanical motion.
• Generators and dynamos — Faraday and Pixii show that rotation naturally produces changing EMF; commutators turn alternating output into useful DC.
• Electricity in thin air — Geissler and Crookes tubes make low-pressure electrical discharges and cathode rays visible.
• The telephone — electrical signals begin carrying the continuously changing waveform of the human voice.
• Electric power and lighting — arc lamps, incandescent lamps, practical lighting loads, and the heated filament that reveals the Edison effect.
• Alternators and transformers — AC generation, magnetic coupling, and voltage conversion make alternating-current power systems practical.
• Radio waves and the photoelectric effect — Hertz proves electromagnetic waves exist and notices in 1887 that ultraviolet light changes electrical emission.
• The induction motor — polyphase currents create a rotating magnetic field and induce current in a brushless rotor.
• Early radio detectors — the coherer and relay turn weak wireless energy into a usable telegraph signal.
• The electron and cathode-ray tube — Thomson identifies the electron and Braun turns a cathode-ray beam into a visual measuring device.
• The vacuum-tube diode — Fleming turns thermionic emission into a one-way electronic valve for detection and rectification.
• The triode — de Forest adds a grid so a small signal can control a larger current, creating the foundation for electronic amplification.
• Radio amplifiers and oscillators — vacuum tubes turn wireless telegraphy into increasingly sensitive receivers and controllable transmitters.
• Test instruments — improved cathode-ray tubes and amplifiers lead to practical oscilloscopes.
• The transistor — solid-state amplification and switching replace many vacuum-tube applications.
• Integrated circuits — many electronic devices are placed together on one piece of semiconductor material.
• Digital electronics and microprocessors — logic, memory, computers, and programmable electronics.
• Modern electronics — increasingly small, fast, inexpensive, and highly integrated systems.