Garage Door Openers, push button simplicity
Electric overhead garage door openers were first invented by C.G. Johnson in 1926 in Hartford
City, Indiana USA. Electric garage Door openers did not become popular until Era Meter
Company of Chicago offered one after World War II where the overhead garage door could be
opened via a key pad located on a post at the end of the driveway or a switch inside the garage.
Contrary to popular belief, the electric garage door opener does not provide the actual lifting power to
open and close a heavy garage door. Instead, most of the actual lifting power comes from the
counterbalance springs attached to the door. These springs are under tension to lift the garage
door via steel cables.
The electric opener only controls how far the door opens and closes, as well as the force the
garage door exerts. In most cases, the garage door opener also holds the door closed in place
of a lock.
The typical electric garage door opener consists of a power unit that contains the electric
motor. The power unit attaches to a track. A trolley connected to an arm that attaches to the
top of the garage door slides back and forth on the track, thus opening and closing the garage
door. The trolley is pulled along the track by a chain, belt, or screw that turns when the motor
is operated. A quick-release mechanism is attached to the trolley to allow the garage door to
be disconnected from the opener for manual operation during a power failure or in case of
emergency. Limit switches on the power unit control the distance the garage door opens and
closes once the motor receives a signal from the remote control or keypad to operate the door.
The entire assembly hangs above the garage door. The power unit hangs from the ceiling and
is located towards the rear of the garage. The end of the track on the opposite end of the power
unit attaches to a header bracket that is attached to the header wall above the garage door. The
power head is usually supported by punched angle iron. Garage door openers have been around for a long time and are becoming more and more popular in this country.
Remote control for garage door openers
The first wireless garage door openers were invented and developed by two US inventors at the
same time unknown to each other, one in Illinois and the other in Washington state USA.
The first garage door openers remote controls were simple and consisted of a simple transmitter
(the remote) and receiver which controlled the opener mechanism. The transmitter would
transmit on a designated frequency; the receiver would listen for the radio signal, then open or
close the garage, depending on the door position. The basic concept of this can be traced back
to World War II. This type of system was used to detonate remote bombs!!
While novel at the time, the technology ran its course when garage door openers became
widely available and used. Then, not only did a person open their garage door, they opened
their neighbor’s garage door as well. While the garage door remote is low in power and in
range, it was powerful enough to interfere with other receivers in the area.
The second stage of the wireless garage door opener system dealt with the shared frequency
problem. To rectify this, multi-code systems were developed. These systems required a
garage door owner to preset a digital code by switching eight to twelve DIP switches on the
receiver and transmitter. While these switches provided garage door systems with a number of
different codes they were not designed with high security in mind; the main intent was to avoid
interference with similar systems nearby. Criminals were able to defeat the basic security of this
system by trying different codes on a regular transmitter. They could also make code grabbers
to record, and re-transmit a signal, or code scanners, that would attempt every possible
combination in a short time. Multi code openers became unpopular in areas where security was
an issue, but due to their ease of programming, such openers are often used to operate such
things as the gates in gated apartment complexes.
The third stage of garage door opener market uses a frequency spectrum range between 300-
400 MHz and most of the transmitter/receivers rely on rolling code technology. This approach
prevents criminals from recording a code and replaying it to open a garage door. Since the
signal is supposed to be significantly different from that of any other garage door remote control,
manufacturers claim it is impossible for someone other than the owner of the remote to open
the garage. When the transmitter sends a code, it generates a new code using an encoder.
The receiver, after receiving a correct code, uses the same encoder with the same original
seed to generate a new code that it will accept in the future. Because there is a high probability
that someone might accidentally push the open button while not in range and erase the code,
the receiver generates look-a-head codes ahead of time. Rolling code is the same method of
security used on the clickers of cars. Garage door openers.
Additional features to Electric garage door openers
● Automatic courtesy lights that turn on when the door opens (or via motion sensors) and
automatically turn off after a preset time delay
● A remote lockout feature, which turns off the radio receiver while one is on vacation or
away for an extended time, therefore rendering your garage door opener in-operable.
● The availability of accessories has increased, including such features as wireless
keypads, key chain remotes, and solenoid-operated deadbolts to lock the door itself.
More sophisticated features are also available, such as an integrated carbon monoxide sensor
to open the door in case of the garage being flooded with exhaust fumes. Other systems allow
door activation over the Internet to allow home operate their garage door opener from their
office for deliveries.
Garage door opener safety
A Hormann promatic unit, readily available in the uk.
The garage door is the largest moving object in a home. An improperly adjusted garage
door opener can exert strong and deadly forces and might not reverse the garage door in an
emergency. The garage door counterbalance springs should be properly adjusted in order for
the safety reverse system to function properly. Thus, proper installation and maintenance are
extremely important in order for the garage door and garage door opener to operate smoothly
The header bracket, which attaches the front end of the opener track to the header wall, must
be securely attached to the structural members of the garage wall. If not, the opener might not
reverse the garage door in an emergency. The rail can also pull away from the wall.
My opinion on electric garage door openers
My opinion is that every time I install one of the above systems I just have to stand back and
smile. I get an enormous amount of pleasure every time I push the button to operate the door.
There are endless reasons why somebody should invest in an electric garage door opener
ranging from security to ease of access for the elderly, disabled or busy mums and dads with
cars full of children and shopping!!
However I cannot help but feel that at the end of the day it also constitutes a good investment in
our homes, one that appeals to owners and future owners alike.
I recommend investing in a spare set of batteries for the remote receiver, because playing with garage door openers is great fun in front of the neighbours!