Second World War. One problem the transmitter had was it would open other people’s garages as well as their own. This was later fixed by using different codes and frequencies.
Garage door openers made it easy for people to access their garages, saved people time and energy and also made it possible to have an “unlock” feature for a garage door where before people had to manually lock and unlock a door if they wanted to protect something in their garage.
Contrary to people’s beliefs, the electronic motor is not what is responsible for the doors opening and closing. It is actually the springs of the door the counterbalance the weight of the door. When the tension builds up on the springs it allows the door to open and close with little effort. The electronic motor then moves the door up and down on the track by a chain.
Obviously the garage door, when open, hangs above the car stall directly below the garage motor. There was a short period of time when the doors would fall off the tracks and wreck people’s cars. Stronger tracks, more secure chains and pulleys helped solve this problem.
Today there are more than ten large garage door opener manufacturers.