differential gears

A 1930s Chevrolet training film explaining the principles and development of the differential gear. It builds the idea step by step from first principles to the finished mechanism.

A 1937 GM-produced film explaining how the automobile differential lets wheels turn at different speeds around a corner. It uses clear animations and cutaway demonstrations to build the idea from first principles.

Rick Hartley's AltiumLive keynote on differential pairs in PC boards. He argues the rules from cables and twisted pairs do not carry over, and covers which pair geometry gives the best impedance control, the right spacing, routing practice and how much skew is acceptable.

A 1953 US Navy training film on the basic mechanisms in fire control computers: shafts, gears, cams and differentials. It shows how these mechanical parts compute ship and target firing solutions.

Neil Fraser of Google presents Differential Synchronization, the algorithm behind MobWrite, for keeping multiple copies of a document in sync in real time. The talk argues the approach is robust, convergent and efficient.

minutephysics, in collaboration with the US Census Bureau, explains differential privacy and why the 2020 census adds noise to protect individuals' data. It walks through how statistics can leak private information.

A 1953 US Navy training film explaining the basic mechanisms in mechanical fire control computers aboard ships. It shows how gears, differentials and cams solved mathematical problems in permanent mechanical form.

A short video illustrating the hazard of pressure differentials (delta P) in commercial diving, where a pressure difference creates enormous force on a diver. It is a safety-oriented look at diving accidents.

A 1936 Chevrolet-sponsored film that explains how a car transmission works by treating gears as spinning levers. It uses physical models to make the mechanism clear.

A Blender-animated explanation of the Toyota Hybrid Synergy Drive, showing how the engine, two motor-generators, planetary gearset and battery work together as an eCVT.

Weber State's Professor Kelly explains the Toyota RAV4 Hybrid transaxle, including its planetary gearset eCVT and all nine operating modes. It also covers how the engine reaches nearly 40 percent thermal efficiency.

The first of an eight-part ScienceClic series building general relativity, covering worldlines, proper time and coordinate systems with animated visualizations.

A Disney Research SIGGRAPH 2013 demo of an interactive system that lets non-experts design animated mechanical characters. The user sketches motion curves and the system generates optimized mechanisms and gear trains for 3D printing.

A short animated explanation of the power split device in Toyota-style hybrids, a planetary gearset that works as an eCVT. It shows how engine and motor power are combined.

Arthur Ganson's kinetic sculpture chains twelve 1:50 worm gear reductions so the final gear, embedded in concrete, would take over two trillion years to turn once.

Dave Jones of EEVblog tears down a Kollsman MD-1 Automatic Astro Compass, a mechanical analog computer from a B-52 bomber. It is part of a star-tracker inertial navigation system that computes altitude and azimuth.

A short clip of Richard Feynman explaining how a train stays on its tracks, through the conical shape of wheels and how it handles curves without differentials.