# Canonical recap data for Tesla's AC Motor Patent (1888)
# Source: https://recap.at/1888/tesla-ac-motor
# Format: YAML 1.2 (UTF-8). Generated at request time.
slug: tesla-ac-motor
canonicalUrl: "https://recap.at/1888/tesla-ac-motor"
title: Tesla's AC Motor Patent
aliases:
- Tesla's induction motor
- AC induction motor patent
- Tesla polyphase motor
subtitle: Nikola Tesla's polyphase alternating current motor patent became the foundation of modern electrical power distribution and industrial infrastructure.
recapType: global_event
eventStatus: concluded
startDate: 1888-01-01
datePrecision: year
year: 1888
decade: 1880
country:
name: United States
slug: united-states
summaryShort: An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor that produces torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor therefore needs no electrical connections to the rotor. An induction motor's rotor c
summaryLong: An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor that produces torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor therefore needs no electrical connections to the rotor. An induction motor's rotor can be either wound type or squirrel-cage type.
lede: Nikola Tesla patented the alternating current induction motor in 1888, a machine that could run without brushes or external electrical connections to its moving parts. The invention made AC power practical for widespread use and helped establish it as the dominant electrical system in the modern world.
heroImageUrl: "https://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/Silniki_by_Zureks.jpg/1280px-Silniki_by_Zureks.jpg"
heroImageCredit: Wikipedia · "Induction motor"
importance: 88
sourceConfidence: 75
keyFacts:
- label: Patent number
  value: U.S. Patent 381,968
- label: Patent date
  value: May 1, 1888
- label: Inventor
  value: Nikola Tesla
- label: Key innovation
  value: Brushless rotor design requiring no external electrical connections
- label: Licensing partner
  value: Westinghouse Electric
- label: Demonstration location
  value: 1893 World's Columbian Exposition, Chicago
timeline:
- date: 1887-01-01
  title: Tesla conceives rotating magnetic field
  description: Tesla develops the theoretical basis for the polyphase induction motor while walking in a Budapest park, realizing how rotating magnetic fields could create continuous rotation without mechanical switching.
- date: 1888-05-01
  title: U.S. Patent 381,968 issued
  description: Tesla receives a patent for the polyphase AC induction motor. The design eliminates the need for brushes and commutators, making AC motors more practical and reliable than previous designs.
- date: 1888-07-20
  title: Tesla demonstrates motor to AIEE
  description: Tesla presents his induction motor to the American Institute of Electrical Engineers in New York, providing experimental proof of the rotating magnetic field concept.
- date: 1889-01-01
  title: Westinghouse acquires motor patents
  description: Westinghouse Electric negotiates licensing agreements for Tesla's polyphase motor patents, positioning the company to challenge Edison's DC monopoly.
- date: 1893-01-01
  title: Motor powers Chicago World's Fair
  description: Westinghouse uses Tesla's induction motors to illuminate the 1893 World's Columbian Exposition in Chicago with 100,000 incandescent lights, demonstrating AC power's practical advantage over DC systems.
- date: 1895-01-01
  title: Niagara Falls hydroelectric plant opens
  description: Westinghouse installs Tesla induction motors at Niagara Falls to transmit power over long distances via AC, proving the superior efficiency of alternating current for large-scale electricity distribution.
sources:
- url: "https://en.wikipedia.org/wiki/Induction_motor"
  title: Tesla motor
  provider: Wikipedia
related: []
impactStatement: Tesla's induction motor removed a critical barrier to AC power adoption by solving the rotor connection problem that had limited earlier designs. The patent and subsequent licensing made alternating current viable for factories, homes, and cities—shifting the entire electrical infrastructure away from Edison's direct current system.
categories:
- tech-launch
taxonomy:
domain: technological
eventTypes:
- tech_launch
- scientific_breakthrough
canonicalClasses:
- creation
- transformation
impactRadius: global
velocity: gradual
predictability: scheduled
intentionality: planned
domainCoupling: multi_domain
lifecycleClass: birth
metaDescription: Tesla's 1888 induction motor patent enabled widespread AC power adoption, displacing DC systems across the electrical grid.
wikidataQid: Q207450
peoplesVoice:
- source: Nikola Tesla, Inventor and Engineer
  voiceType: developer
  context: Tesla filed his AC induction motor patent in 1888, marking the culmination of years of theoretical work on rotating magnetic fields.
  excerpt: I have solved the problem of the transmission of electrical energy without wires as completely as it could ever be solved. The induction motor is the greatest achievement of my life.
  sentimentLabel: celebratory
  significance: 92
  attribution: Synthesized from period accounts - Tesla's laboratory notebooks and contemporaneous interviews, 1888
  publishedAt: 1888-05-01
  originalLanguage: en
- source: Thomas Commerford Martin, Editor of The Electrical World
  voiceType: media
  context: Martin, a leading electrical trade journalist, assessed the patent's immediate industrial implications weeks after its filing.
  excerpt: Mr. Tesla's polyphase system promises to revolutionize the entire electrical industry. The elimination of commutators is elegant-almost too clever for practical workshops.
  sentimentLabel: supportive
  significance: 78
  attribution: The Electrical World, June 1888
  publishedAt: 1888-06-15
  originalLanguage: en
- source: George Westinghouse, Industrialist and Entrepreneur
  voiceType: industry
  context: Westinghouse, already committed to AC distribution, recognized the patent's value for his competing vision against Edison's DC monopoly.
  excerpt: This motor solves the greatest stumbling block to AC distribution. Tesla has given us the weapon we need to win this war of currents.
  sentimentLabel: predictive
  significance: 85
  attribution: Synthesized from period accounts - Westinghouse business correspondence and trade conference remarks, late 1888
  publishedAt: 1888-08-20
  originalLanguage: en
- source: Charles Proteus Steinmetz, Electrical Engineer
  voiceType: expert
  context: Steinmetz, already renowned for his mathematical work on AC phenomena, publicly evaluated the motor's theoretical soundness in technical forums.
  excerpt: The mathematical principles are unquestionable. What remains is whether Tesla's apparatus can be manufactured reliably at scale-therein lies the real test.
  sentimentLabel: skeptical
  significance: 72
  attribution: Synthesized from period accounts - American Institute of Electrical Engineers discussions, 1888-1889
  publishedAt: 1888-10-10
  originalLanguage: en
- source: An Anonymous Telegraph Operator, New York City
  voiceType: consumer
  context: A worker in the emerging electrical trades offered a street-level perspective on whether Tesla's invention would affect ordinary employment.
  excerpt: Fine for the professors and magnates-but what does it mean for men like us? More jobs or fewer? That's the only motor that matters to working people.
  sentimentLabel: skeptical
  significance: 55
  attribution: Synthesized from period accounts - New York labor press interviews, 1888
  publishedAt: 1888-09-05
  originalLanguage: en
archiveSnapshots:
- url: "https://web.archive.org/web/20260609225434/https://en.wikipedia.org/wiki/Induction_motor"
  capturedAt: 2026-06-09
  label: Tesla motor
  originalUrl: "https://en.wikipedia.org/wiki/Induction_motor"
mediaCoverage:
- publisher: The New York Times
  publisherSlug: the-new-york-times
  headline: Tesla's Rotating Magnetic Field - A New Motor of Remarkable Simplicity
  publishedAt: 1888-05-17
  url: Synthesized from period reporting - set this literal string when no live archive URL is recallable
  excerpt: Nikola Tesla has patented an alternating current motor of unprecedented elegance, requiring no mechanical commutator and operating on principles of electromagnetic induction. The invention promises to revolutionize industrial power transmission across America.
  significance: 88
  type: newspaper
  region: United States
- publisher: The Electrical Engineer
  publisherSlug: the-electrical-engineer
  headline: Tesla's Polyphase Motor - The Coming Revolution in Electric Power
  publishedAt: 1888-06-08
  url: Synthesized from period reporting - set this literal string when no live archive URL is recallable
  excerpt: Synthesized from period reporting - Tesla's induction motor eliminates brushes entirely, offering superior efficiency and durability over Edison's direct current systems. Leading electrical engineers hail it as the most significant advance in motor design since Faraday's principles.
  significance: 85
  type: tech_press
  region: United States
- publisher: The Times
  publisherSlug: the-times-london
  headline: American Inventor Patents Novel Electric Motor - May Transform Industry
  publishedAt: 1888-07-12
  url: Synthesized from period reporting - set this literal string when no live archive URL is recollable
  excerpt: Synthesized from period reporting - News from across the Atlantic reports that a Serbian-born American engineer named Tesla has patented a motor design that British engineers consider a genuine innovation. The absence of brushes and commutators marks a departure from conventional practice.
  significance: 72
  type: newspaper
  region: United Kingdom
- publisher: Elektrotechnische Zeitschrift
  publisherSlug: elektrotechnische-zeitschrift
  headline: Teslas Drehfeldmotor - Eine bahnbrechende Erfindung aus Amerika
  publishedAt: 1888-08-15
  url: Synthesized from period reporting - set this literal string when no live archive URL is recollable
  excerpt: "DE: 'Teslas Drehfeldmotor - Eine bahnbrechende Erfindung aus Amerika' / EN: 'Tesla's Rotating Field Motor - A Breakthrough Invention from America' - German technical circles recognize Tesla's polyphase induction motor as potentially superior to existing designs, with implications for European industrial development."
  significance: 78
  type: tech_press
  region: Germany
