garage door opener is a motorized device that opens and closes the garage door. Most are controlled by switches in the garage wall, as well as by remote controls brought by the owner.
Video Garage door opener
Opener
The electric overhead garage door opener was created by C.G. Johnson in 1926 in the City of Hartford, Indiana. Opener Electric Door did not become popular until Era Meter The Chicago company offered one after World War II where the garage door above could be opened via a button located at a post at the end of the driveway or a switch inside the garage.
Like in an elevator, the electric motor does not provide most of the power to move a heavy garage door. In contrast, most of the weight of the door is offset by a balancing spring attached to the door. (Even manually operated garage doors have a counterweight, otherwise it would be too much for a person to open or close them.) In a typical design, the torque spring applies torque to the shaft, and the shaft implements the force to the garage door through the steel counter cable. Electrical opener only provides a small amount of power to control how far the door opens and closes. In many cases, the garage door opener also holds the closed door as a key.
A typical electric garage door opener consists of a power unit containing an electric motor. The power unit is attached to the track. The trolley connected to the arm attached to the top of the garage door shifts forward and back on the track, thus opening and closing the garage door. The trolley is pulled along the track by a chain, belt, or screw that rotates when the motor is operated. The rapid discharge mechanism is attached to the trolley to allow the garage door to be disconnected from the opening for manual operation during power failure or in an emergency. The switch limit on the power unit controls the distance of the open garage door and closes after the motor receives the signal from the remote control or the wall knob to operate the door.
The whole assembly hangs over the garage door. The power unit hangs from the ceiling and is located at the back of the garage. The end of the track at the opposite end of the power unit is attached to the crown bracket attached to the crown wall above the garage door. The power head is usually supported by a forged angle iron.
Recently other types of enthusiasts, known as jackshaft openers, have become more popular. This opening style is often used on commercial doors but in recent years has been adjusted for home use. This opening style consists of a motor attached to the torso side and moves the door up and down just by rotating the stem. This opener requires several additional components to work safely for home use. This includes a cable voltage monitor, to detect when the cable is broken, and a separate locking mechanism to lock the door when it is fully closed. It has the advantage that they are liberating the ceiling space that will be occupied by regular opener and rails. It also has the disadvantage that the door should have a torso to install the motor.
Maps Garage door opener
Type
There are five types of garage door openers. Drive chain, belt drive, screw drive, direct drive, and jackshaft.
The chain drive opener has a chain (similar to a bicycle) that connects the trolley to the motor.
Belt drive opener using rubber belt instead of chain.
The screw drive opener has a long screw inside the track. The trolley is connected to this screw.
Direct Drive openers have motor mounted in the trolley and use the gear to drive the trolley along the fixed chain.
The jackshaft opener is mounted on the wall at both ends of the torso.
Remote control
The first wireless garage door opener was created and developed by two US inventors at the same time, one in Illinois and the other in Washington state. They are not known to each other.
The first garage door opener is a simple remote controller and consists of a simple transmitter (remote) and a receiver that controls the opening mechanism. The transmitter will transmit at a specified frequency; the receiver will listen to the radio signal, then open or close the garage, depending on the position of the door. This basic concept can be traced back to World War II. This type of system is used to detonate long-range bombs. While the novel at the time, technology runs by itself when garage door opener becomes popular. While the garage door remote controller has low power and limited reach, the signal can be received by another, close, garage door opener. When two neighbors open the garage door, then open one garage door may open the door of the neighbor's garage as well.
The second phase of the wireless garage door opener solves the problem of neighboring opening doors. The remote control on this system sends a digital code, and the recipient in the garage responds only to the code. Code is usually set by eight to twelve DIP switches on the receiver and transmitter, so they are allowed to 2 8 = 256 to 2 12 = 4.096 different code. As long as the neighbors use different codes, they will not open the garage door to each other. The purpose of this system is to avoid interference with the nearest garage door; the system is not designed with security in mind. The intruder is able to defeat the security of this system and into the garage and the house. The amount of code is small enough even an unsophisticated intruder with a compatible remote control transmitter can only start transmitting all possible codes until he finds one that opens the door. More advanced intruders can get a black box master key that automatically sends every possible code in no time. A more sophisticated method is known as a replay attack. The attacker will use a code grabber, which has a receiver that captures the remote digital code and can resend the digital code at a later time. Attackers with a code grabber will wait nearby for the homeowner to use his remote, catch the code, and then replay the code to open the door when the owner of the house goes. Multicode enters are becoming unpopular in areas where security is important, but because of their ease of programming, such openers are often used to operate things like gates in gated apartment complexes.
A transitional stage of the garage door opener eliminates the DIP switch and uses the programmable remote into one of about 3.5 billion unique codes. The recipient will keep a list of remote security that will be responded to; users can easily add a unique remote code to the list by pressing the button on the garage door opener when activating the remote control. The sheer number of codes makes gameplay-force try-all-possible-digital-codes unfeasible, but the system is still vulnerable to code grabs. For the convenience of users, the system is also compatible with the old DIP remote switch code, but adding old technology remotes to the security list makes garage door openers vulnerable to brute force attacks to find DIP switch codes. The larger code space approach is an improvement over the fixed DIP switch code, but is still vulnerable to replay attacks.
The third phase of garage door opener uses a frequency spectrum range between 300-400 MHz and code hopping technology to overcome code grabs. In addition to transmitting unique identifiers to the remote control, sequential numbers and encrypted messages are also sent. Although the intruder can still catch the code used to open the garage door, the serial number will end soon, so retransmitting the code will not open the garage door. Encryption makes it very difficult for an intruder to forge messages with the next sequence number that will open the door. Some rolling code systems are more involved than others. Because there is a high probability that someone will press the remote button while not within range and thus advance the sequential number, the recipient does not demand the sequence number to increase exactly one; it will receive a serial number that is inside a narrow window or two consecutive serial numbers in a much larger window. The scrolling code technology is also used on remote control cars and with some internet protocols for secure sites.
The fourth stage of the garage door opener is similar to the third stage, but is limited to 315 MHz. The frequency range 315Ã, MHz avoids interference from Land Line Radio Systems (LMRS) used by the US military.
The following standards are used by units produced by Chamberlain (including LiftMaster and Craftsman):
* Not applicable to keypad keyless keypad or universal remote.
Chamberlain garage door openers that recently feature Security 2.0 also use special serial protocols on cable connections rather than simple switch closures.
The following standards are used by units manufactured by Overhead Door Corporation and its subsidiary The Genie Company:
Note: There is no standard color code for learning buttons or LEDs on units manufactured by Overhead or Genie Doors. All accessories created for older versions of Genie Intellicode and Overhead Door CodeDodger are compatible with previous Intellicode and CodeDodger generations.
Cloned garage door opener
Many remote control garage door openers use a fixed code encoding that uses DIP switches or soldering to perform address pin encoding processes, and they usually use pt2262/pt2272 or a compatible IC. For this fixed-code garage door opener, one can easily clone an existing remote using a remote control self-copy duplicator (remote copy) that can make remote copies using face-to-face copying.
Additional features
Additional features that have been added over the years include:
- Automatic lights illuminated when the door is open (or via motion sensor) and automatically turns off after a pre-set delay
- Remote lockout feature, which turns off the radio receiver while on vacation or goes away for a long time.
- Accessory availability has increased, including features such as wireless keypads, remote lock chains, and solenoid-operated locks to lock the door itself.
More sophisticated features are also available, such as an integrated carbon monoxide sensor to open the door if the garage is flooded with exhaust fumes. Other systems allow door activation over the Internet to allow homeowners to open their garage doors from their offices for delivery.
Another recent innovation in garage door opener is a fingerprint-based wireless keypad. This unit attaches to the outside of the garage door on the frame and allows the user to open and close their door by pressing a finger, rather than creating a personal identification number (PIN). This is very useful for families with children who might forget the code and the pigtails.
Security
Garage doors are generally the largest moving objects in the home. Unconfused garage door opener can create strong and deadly power and may not reverse the garage door in an emergency. The manufacturer's instructions provide guidance to the user on proper adjustment and maintenance of the opening.
Garage door openers manufactured and installed in the United States since 1982 are required to provide a rapid discharge mechanism on trolleys that allow garage doors to be disconnected from garage door openers in case of traps. Garage door opener manufactured since 1982 is also needed to reverse the garage door if it attacks solid objects.
Under US federal law (UL 325), garage door openers created for the US since 1993 should include a secondary security reversal system, such as an eye or photoelectric sensor, mounted near the floor. Another example of a safety reversal system, permitted in the UL 325 guidance, includes an electrical safety edge, which reverses with about 15 pounds of downward pressure, and a garage door and an eyeless photo opening system, tested together, which reverses about 15 pounds of pressure.
References
External links
- Official FCC notice on garage opening frequency (PDF)
- The Garage Opener Security Tips (Washington Post)
- Commission Regulation Safety For Automatic Garage Door - U.S. Consumer Product Safety Commission CPSC, 1992
Source of the article : Wikipedia
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