We have all seen them. Those little boxes that clip on to the visor of the car or even the smaller version that clips right onto your key ring. For anyone who has stood in a freezing rainstorm trying to get the garage door open, these little boxes, otherwise known as garage door opener transmitters, are about the best invention since sliced bread.

Garage door opener transmitters have come a long way since they first went on the market right after World War II. These transmitters operated on the same basic principle as the remote bomb detonators used in World War II. These transmitters were operated off a single frequency radio signal. They were low-powered and only had a short range. Using these short-ranged transmitters became problematic. When garage door opener transmitters first became popular, a glitch became very apparent. Many times the user would end up causing his neighbor’s garage door to open as well as his own. Some people thought it was fun to just drive up and down streets to see how many garage doors they could open as they drove by. Needless to say, complaints from customers led to research and improvements.

By the 1970s, garage door opener transmitters became more sophisticated. Because owners were able to alter the frequency on their transmitters and on their garage door opener, pranksters were no longer able to randomly open garage doors. Owners would alter the frequency simply by adjusting the dip switches in their transmitter and the dip switches in their garage door opener. This did provide more security; however, not as much as you would think. There were only 8 dip switches, which meant that there was the possibility of 256 combinations. If access was wanted badly enough, it was still possible by using a method of deduction or a device known as a grabber. This device literally grabbed the code right out of the air allowing access to the garage and most times to the home as well.

Through research and innovation, manufactures came up with a new technology. This technology is called rolling code technology. This technology produces billions of possible combinations of code. Each time a garage door opener transmitter is used, the code is changed. Code grabbers are useless against this technology since the code used last is no longer valid. This provides the best security technology that can be provided to keep garages and homes safe from intruders.

Garage door opener transmitters are available in a number of different styles and have several different functions. Along with the visor and key chain styles, you can get transmitters that are wireless-keyless, wall mount, and the Homelink remote that is installed in a few newer vehicles.

Just like the universal remote for your television, multi-button remotes could be set up to operate not only your garage door opener, but also other locks, doors and lights.

Be careful if you have to replace your garage door opener transmitter. Be certain that the replacement you are considering is compatible with the garage door opener you have. Even universal transmitters do not operate all brands so make sure to read the package thoroughly before purchasing. If you are having problems with a visor or key chain garage door opener transmitter, try changing the battery. Most times this will solve the problem.