AWhat changed
Tesla explains how phase-displaced alternating currents create a rotating magnetic field and describes synchronous and closed-rotor-coil motor forms that use it.
Scientific scope
Tesla explains how phase-displaced alternating currents create a rotating magnetic field and describes synchronous and closed-rotor-coil motor forms that use it. The target is the May 1888 lecture's rotating-field motor and transformer construction, crosschecked with US 381968 and an approved 1894 reprint. A constant field assumes weak-magnetization proportionality, a uniform generator field and constant-speed quadrature currents. Synchronous speed holds within load and capacity limits; closed-rotor-coil torque motors have load-dependent speed and slip. DC-excited and rotating-winding variants differ. Sliding contacts disappear in certain stationary-primary forms, not universally. Claims of instantaneous reversal, equal DC torque and better efficiency are author statements, not independently replayed benchmarks; later tests reported in 1894 are not backdated. A patent discloses a design without certifying performance, safety, deployment or global priority. Ferraris's original body is unread, so exclusive first rotating-field or induction-motor claims are withheld. The lecture transcription and edited reprint are not first-print facsimiles; illustrations were not inspected. Earlier induction and later industrial engineering retain separate credit.
Evidence
Source-linked, scoped account of the original work. The published scope states the scientific assumptions and remaining verification limits. WRS has not independently certified the full proof, experimental result or system benchmark.
Contributors
- Nikola Tesla · SCIENCE: Original source-listed scientific author of this scoped work; byline does not determine effort fractions.
- Nikola Tesla, A New System of Alternating Current Motors and Transformers (May 1888), society-hosted lecture transcription
- Nikola Tesla, Electro-magnetic motor, US 381968 A, original 1888 patent specification
- Thomas Commerford Martin, The Inventions, Researches and Writings of Nikola Tesla (1894), authorized collected reprint
- Galileo Ferraris, Rotazioni elettrodinamiche prodotte per mezzo di correnti alternate (1888), publisher bibliography
Provisional WRS assessment, edition 2026-10-16.1. Independent expert calibration is pending. This grade does not certify correctness or assign ownership.
Full scientific record · Browse contribution grades · Request a correction