Garage Door Openers Ryan CowanIDS 1999 Blake

The Electric Opener  C.G. Johnson 1926 in Hartford City Indiana  Spring  Electric motor  Controls  Runs on a track

Remote Control  Two U.S. inventors  Transmitter & receiver  Designated frequency

Cloning Remotes  Same Operating Frequency  Only Fixed Code  Clone Remote Must Be Cleared

Additional Features  Automatic Light  Remote Locks  Keychain and Deadbolt

Safety  Motion Sensor  Must Have Quick Release  Children Should Never Operate

Video 

Sources   or-projects/garage-door-opener-how-it-works