In telecommunications, squelch is a circuit function that acts to suppress the audio output of a receiver in the absence of a strong input signal. Essentially, squelch is a specialized type of noise gate designed to suppress weak signals. Squelch is used in two-way radios and VHF/UHF radio scanners to eliminate the sound of noise when the radio is not receiving a desired transmission.
In electronics, a remote control is an electronic device used to operate another device from a distance, usually wirelessly. In consumer electronics, a remote control can be used to operate devices such as a television set, DVD player or other home appliance. A remote control can allow operation of devices that are out of convenient reach for direct operation of controls. They function best when used from a short distance. This is primarily a convenience feature for the user. In some cases, remote controls allow a person to operate a device that they otherwise would not be able to reach, as when a garage door opener is triggered from outside.
Radio control is the use of control signals transmitted by radio to remotely control a device. Examples of simple radio control systems are garage door openers and keyless entry systems for vehicles, in which a small handheld radio transmitter unlocks or opens doors. Radio control is also used for control of model vehicles from a hand-held radio transmitter. Industrial, military, and scientific research organizations make use of radio-controlled vehicles as well. A rapidly growing application is control of unmanned aerial vehicles for both civilian and military uses, although these have more sophisticated control systems than traditional applications.
A DIP switch is a manual electric switch that is packaged with others in a group in a standard dual in-line package (DIP). The term may refer to each individual switch, or to the unit as a whole. This type of switch is designed to be used on a printed circuit board along with other electronic components and is commonly used to customize the behavior of an electronic device for specific situations.
The Chamberlain Group, Inc. v. Skylink Technologies, Inc., 381 F.3d 1178 is a legal case heard by the United States Court of Appeals for the Federal Circuit concerning the anti-trafficking provision of the Digital Millennium Copyright Act (DMCA), 17 U.S.C. § 1201(a)(2), in the context of two competing universal garage door opener companies. It discusses the statutory structure and legislative history of the DMCA to help clarify the intent of the anti-circumvention provisions and decide who holds the burden of proof. It expresses that the statute creates a cause of action for liability and does not create a property right, and holds that as Chamberlain had alleged that Skylink was in violation of the anti-trafficking provision, it had the burden to prove and failed to show that access was unauthorized and its rights were infringed under the Copyright Act. As Chamberlain incorrectly argued that Skylink had the burden of proof and failed to prove their claim, the court upheld summary judgment in favor of Skylink.
A garage door opener is a motorized device that opens and closes a garage door controlled by switches on the garage wall. Most also include a handheld radio remote control carried by the owner, which can be used to open and close the door from a short distance.
A smart key is an electronic access and authorization system that is available either as standard equipment, or as an option in several car designs. It was first developed by Siemens in 1995 and introduced by Mercedes-Benz under the name "Keyless-Go" in 1998 on the W220 S-Class, after the design patent was filed by Daimler-Benz on May 17, 1997.
A remote keyless system (RKS), also known as remote keyless entry (RKE) or remote central locking, is an electronic lock that controls access to a building or vehicle by using an electronic remote control (activated by a handheld device or automatically by proximity). RKS largely and quickly superseded keyless entry, a budding technology that restrictively bound locking and locking functions to vehicle-mounted keypads.
A residential garage is a walled, roofed structure for storing a vehicle or vehicles that may be part of or attached to a home, or a separate outbuilding or shed. Residential garages typically have space for one or two cars, although three-car garages are used. When a garage is attached to a house, the garage typically has an entry door into the house, called the person door or man door, in contrast with the wider and taller door for vehicles, called the garage door, which can be raised to permit the entry and exit of a vehicle and then closed to secure the vehicle. A garage protects a vehicle from precipitation, and, if it is equipped with a locking garage door, it also protects the vehicle(s) from theft and vandalism. Most garages also serve multifunction duty as workshops for a variety of projects, including painting, woodworking, and assembly. Garages also may be used for other purposes as well, such as storage or entertainment.
A garage door is a large door on a garage that opens either manually or by an electric motor. Garage doors are frequently large enough to accommodate automobiles and other vehicles. The size of the garage doors varies. Small garage doors may be made in a single panel that tilts up and back across the garage ceiling. Larger doors are usually made in several jointed panels that roll up on tracks across the garage ceiling, or into a roll above the doorway. The operating mechanism is usually spring-loaded or counterbalanced to offset the weight of the door and reduce the human or motor effort required to operate the door. Less commonly, some garage doors slide or swing horizontally. Doors are made of wood, metal, or fiberglass, and may be insulated to prevent heat loss.
A land mobile radio system (LMRS) is a person-to-person voice communication system consisting of two-way radio transceivers which can be stationary, mobile, or portable.
A pet door or pet flap is a small opening to allow pets to enter and exit a building on their own without needing a human to open the door. Originally simple holes, the modern form is a hinged and often spring-loaded panel or flexible flap, and some are electronically controlled. They offer a degree of protection against wind, rain, and larger-bodied intruders entering the dwelling. Similar hatches can let dogs through fences at stiles. A related concept is the pet gate, which is easy for humans to open but acts as a secure pet barrier.
A rolling code is used in keyless entry systems to prevent replay attacks, where an eavesdropper records the transmission and replays it at a later time to cause the receiver to 'unlock'. Such systems are typical in garage door openers and keyless car entry systems.
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 3,000 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by another antenna connected to a radio receiver. Radio is widely used in modern technology, in radio communication, radar, radio navigation, remote control, remote sensing, and other applications.
An electric gate is a type of gate that can be opened and closed using an electrically powered mechanism.
The HomeLink Wireless Control System is a radio frequency (RF) transmitter integrated into some automobiles that can be programmed to activate devices such as garage door openers, RF-controlled lighting, gates and locks, including those with rolling codes.
An elevator or lift is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems such as a hoist, although some pump hydraulic fluid to raise a cylindrical piston like a jack.
An RF module is a (usually) small electronic device used to transmit and/or receive radio signals between two devices. In an embedded system it is often desirable to communicate with another device wirelessly. This wireless communication may be accomplished through optical communication or through radio-frequency (RF) communication. For many applications, the medium of choice is RF since it does not require line of sight. RF communications incorporate a transmitter and a receiver. They are of various types and ranges. Some can transmit up to 500 feet. RF modules are typically fabricated using RF CMOS technology.
Chamberlain Group (CGI), the corporate parent company to LiftMaster, Chamberlain, Merlin, and Grifco, designs and engineers residential garage door openers, commercial door operators, and gate entry systems.
HomeKit, also known as Apple Home, is a software framework and communication protocol developed by Apple Inc. that lets users configure, communicate with and control smart-home appliances using Apple devices. It provides users with a way to automatically discover such devices and configure them. By designing rooms, items and actions in HomeKit, users can enable automations in the home through a voice command to Siri or through the Home app. With HomeKit, developers are able to create complex applications in order to manage accessories at a high level.
