Garage door motors

In the previous posts I referred to a couple of features of garage door motorization which were not fully explained, so I will elaborate on them now.

Soft start and soft stop

The first is known most commonly as “soft start” and “soft stop” and describes the movement of the garage door at the start and end of its transition from an open to a closed state, or vice versa.

One of the wear and durability problems of early motorised garage door mechanisms was the abrupt start of the door’s motion as the initial movement kicked in, and an equivalent sudden stop as the door hit the frame and its movement ended.

The shock, vibration and general crudeness of this motion did nothing for the garage door's lifespan or appearance during operation, so smoother mechanisms were invented.

Soft start and soft stop garage doors use variable speed so that the initial and final movement of the door is much slower and more controlled. This makes the opening process look better and, more importantly, avoids jolts, jerky movements and additional stress to the door, frame and motor.

Obstruction detection

There are lots of names for a feature that can be generally described as “obstruction detection”.

What this feature does is act as a safety precaution in the event of a human being, animal, or other object blocking the path of the door during opening or closing.

This is critical as garage doors are heavy and the motors that power them are strong. This can be a dangerous combination for anything that inadvertently falls within the path of a moving garage door.

Obstruction detection features use different methods to ensure that the motion of the door is terminated by any obstruction or physical contact with the door and this can be achieved in two ways.
1. The more expensive and less sophisticated way is the use a detector (e.g. laser) to recognise an obstacle blocking the doors path. This triggers a stop action and the door discontinues its motion until the detector reads the area as clear.

2. More popular is a garage door motorization feature that is often referred to as “learning” or “training”. This feature is simple but effective and it relies on the garage door recognising its own movement pattern. It works by spotting any change caused by the door hitting an object (i.e. slowing it down) and this in turn causes the door to halt its movement. Obviously this approach does not predict and stop the door before it makes contact with the obstacle, but it is effective and is often included as a standard feature on many garage door motorization kits.