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33-912: Intercoms are used on a wide variety of properties; from houses that only require one connection between a resident and the property's entrance to multi-unit apartments that require intercom hardware to be installed in every individual apartment. Some are equipped with video and its wiring (electrical installation) can be connected to the outside with a few pairs (4-6 pairs) while controlling an electric strike . The latest generations are even compatible with computers and some models include TCP/IP compatibility. Traditional intercoms and public address systems are composed entirely of analogue electronics components but many new features and interfacing options can be accomplished with new intercom systems based on digital connections. Video signals can be carried as well as voice. Digital intercom stations can be connected using Cat 5 cable and can even use existing computer networks as

66-791: A Master to an IP Substation elsewhere on the Internet, via an Ethernet port. Wireless intercoms can also run over a mesh network that allows near-instant communication throughout a house. Power line communication units that send signal over house wiring have been referred to as "wireless" intercoms. Though they are technically wired intercoms, they are based on existing wiring and thus require no additional wires. Some telephones include intercom functions that enable paging and conversation between instruments of similar make and model. Examples include Panasonic model KX-TS3282W(/B), AT&T models 945 and 974, and TMC model ET4300. A single device can add intercom functionality to multiple standard telephones on

99-427: A combination of permanently mounted and portable intercom elements. Motorsports race tracks often have both portable and permanent intercom stations mounted at critical points around the racecourse for use by race officials and emergency medical technicians . Portable intercoms are also used for motorcycle communication, for example between motorcyclist and passenger, bike-to-bike communication or communication within

132-476: A common phone line, even of different makes and models. Installation effort is minimal, and is not vulnerable to the radio interference and security issues of wireless systems. The Add-A-Com Whole House Intercom for Standard Telephone Systems is such a device. Intercom paging is accomplished by sounding a distinctive ring from all telephones after any phone is taken briefly off hook. After paging, any number of phones may converse. The device temporarily disconnects

165-636: A means of interfacing distant parties. Intercom cameras can be used in modern offices and hotels. Many schools and office buildings now use audio / video systems to identify visitors trying to gain access to a locked building and can be interfaced with the building's access control system. Besides fixed locations, intercom systems are used on many types of vehicles including trains , watercraft , aircraft and armoured fighting vehicles . Portable intercoms are commonly used by special event production crews and professional sports teams. Performing arts venues such as theaters and concert halls often have

198-409: A pack of riders. Intercom mounting systems can be attached to most motorcycle helmets . Several different types of technologies can be used, including various types of citizens band radio like for example PMR446 , Bluetooth , or dynamic mesh communication (DMC) which is a mesh based intercom system developed for motorcycle communication. Intercom installers, suppliers, and manufacturers often use

231-402: A rim panic strike, means the strike is bolted to the surface of jamb without cutting into the frame or modifying it in any way (except for the drilling and tapping of mounting screw and/or anchoring pins). There are also specialty electric strikes used in vertical rod exit devices, however the exit device's bottom rod is usually deactivated and the specialty electric strike is mounted at the top of

264-600: A scanner, baby monitor, cordless phone, or a similar device on the same frequency. Encrypted wireless intercoms can reduce or eliminate privacy risks, while placement, installation, construction, grounding and shielding methods can reduce or eliminate the detrimental effects of external interference. The United States and Canada have several frequency ranges for wireless intercom systems and other wireless products. They are 49 MHz, FM band (200–270 kHz), 494–608 MHz, 900 MHz, 2.4 GHz, 5.8 GHz, and MURS (150 MHz). IP Intercoms are now appearing that connect

297-528: A similar manner with shielded cabling often containing more than one twisted pair. Digital intercoms use Category 5 cable and relay information back and forth in data packets using the Internet protocol suite . Intercom systems are widely used in TV stations and outside broadcast vehicles such as those seen at sporting events or entertainment venues. There are essentially two different types of intercoms used in

330-729: Is an outdoor device that communicates wirelessly over the cell phone network with any landline or mobile phone worldwide. Often called GSM intercoms, they initially used the Global System for Mobile Communications standard, and the intercoms were first released in European countries. This standard is now used globally, though in the United States, primarily AT&T, T-Mobile, and a few other providers use GSM, while Sprint and Verizon used CDMA (Code Division Multiple Access) technology. Modern cell phone intercoms support all carriers and

363-606: Is that installation is much easier since no wires have to be run between intercom units. The second is that you can easily move the units at any time. With that convenience and ease of installation comes a risk of interference from other wireless and electrical devices. Nearby wireless devices such as cordless telephones, wireless data networks, and remote audio speakers, as well as structural features in your building, can all interfere. Electrical devices such as motors, lighting fixtures and transformers can cause noise. There may be concerns about privacy since conversations may be picked up on

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396-472: Is thrown and it engages in the electric strike cavity, the electric strike can release it but cannot subsequently 'recapture it' since the deadbolt lacks the spring latching capability of the other lock sets). There are specialty electric strikes that hold the electric strike keeper open until the door with the extended deadbolt closes back into the electric strike to "recapture" the extended deadbolt. Mortise type locksets tend towards larger projecting latches from

429-399: The technical director , production manager , charge artist , and property master . Scenic designers create scale models of the scenery, artistic renderings , paint elevations, and scale construction drawings to communicate with other production staff. Additionally, more senior members of a television show's writing staff are credited as producers, with the specific title dependent upon

462-499: The A1 is the primary audio engineer responsible for the technical design and operation of associated sound systems (e.g. mixers, microphones, intercom, IFB, RF equipment, PA/monitoring, music/sfx playback, multi-track recording, and more). Generally speaking, the A1 supervises all audio crew members during build, rehearsal, and show phases of any production. Ultimately, the A1 will have routed, recorded, and mixed all sound sources heard during

495-408: The door frame to work with the top latch of the vertical rod exit device. Television crew Television crew positions are derived from those of film crew , but with several differences. The scenic designer collaborates with the theatre director and other members of the production design team to create an environment for the production, and then communicates details of this environment to

528-403: The door it can work with. The four most common locking mechanisms concerned with electric strikes are Cylindrical, Deadbolt, Mortise, and Rim Panic Exit Devices. Cylindrical electric strikes are generally the cheapest due to their use in residential markets. Deadbolts, also known as deadlocks, do not have a spring mechanism which generally means the strike for a deadbolt is 'hold' only (the deadbolt

561-501: The door to engage deeper in the frame and electric strikes used for these locking mechanisms require more cutting and space in the frame. Rim exit devices (panic bars or crash bars) are required in many buildings as a 'single motion' means of egress and electric strikes used in these situations are typically different from electric strikes for other situations. Electric strikes for rim panic exit devices are sometimes, though not always, 'no cut' electric strikes - no cutting, in reference to

594-594: The external phone line during intercom use, and reconnects when all phones are again on hook. During intercom use, an external call’s ringing signal can be heard in the earpiece. Many key telephone systems for office use provide access to multiple outside lines plus an intercom, where the latter appeared as if it were one of the individually-selectable lines. The Western Electric Model 207 and Model 6A intercoms were designed for integration into such key system multiline installations, providing one or two simultaneous intercom calls respectively. A cell phone network intercom

627-497: The external user stations as well as communicate, there would usually be a pop when the channels were switched. So while one could change the system on-the-fly, it was usually not desirable to do so in the middle of a production, as the popping noise would distract the rest of the television crew . In the mid-90s four-wire technology started gaining more prominence due to the technology getting cheaper and smaller. Four-wire circuit technology had been around for quite some time but

660-419: The following terms to refer to intercom components. While every intercom product line is different, most analogue intercom systems have much in common. Voice signals of about a volt or two are carried atop a direct current power rail of 12, 30 or 48 volts which uses a pair of conductors. Signal light indications between stations can be accomplished through the use of additional conductors or can be carried on

693-458: The function within seconds (usually take less than 10 seconds) with only the movement of two external screws or a mechanical unlocking accessory which is directly accessible when the door is open. This is exactly the same principle as a child safety door lock which is installed on car doors. Electric strikes on AC allow someone outside the door to hear when the door is open. The buzzing noise is typically made by applying alternating current (AC) to

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726-402: The keeper returns to its standard position and re-locks when power is removed or applied, depending upon the strike's configuration. Electric strikes are generally available in two configurations: A new trend is a strike that is quickly reversible from fail safe to fail secure (and back again if needed). Some manufacturers require the opening of the solenoids, but others allow the reversing of

759-418: The latest technologies. Commonly installed at gates or doors, they are popular because they eliminate the need for wiring, except for power. Electric strike An electric strike is an access control device used for door frames . It replaces the fixed strike faceplate often used with a latch (also known as a keeper ). Like a fixed strike plate, it normally presents a ramped or beveled surface to

792-529: The length of the faceplate. Only in fail-safe situations, it is also a good option to choose a magnetic lock . Before using a magnetic lock, the Fire Marshal or appropriate authority should be consulted. There are emergency egress issues that must be addressed before using a magnetic lock. Electric strikes can be differentiated in a number of ways, frame type it can be installed in, duty (continuous or intermittent), and which variety of locking mechanism on

825-404: The locking latch allowing the door to close and latch just like a fixed strike would. However, an electric strike's ramped surface can, upon command, pivot out of the way when the lock on the door is in the locked position and the door is opened, allowing a user to pull/push the door to open it without operating the mechanical lock or using a mechanical key. After the door is opened past the keeper,

858-595: The main voice pair via tone frequencies sent above or below the speech frequency range. Multiple channels of simultaneous conversations can be carried over additional conductors within a cable or by frequency- or time-division multiplexing in the analogue domain . Multiple channels can easily be carried by packet-switched digital intercom signals. Portable intercoms are connected primarily using common shielded, twisted pair microphone cabling terminated with 3-pin XLR connectors . Building and vehicle intercoms are connected in

891-461: The program broadcast. The A2 helps get microphones or other audio devices to the right place or to the right person The publicist ensures the media are well aware of a project by distributing the show as a trial run or sneak preview. They issue press releases and arrange interviews with cast and crew members. They may arrange public visits to the set, or distribute media kits that contain pictures, posters, clips, shorts, trailers, and descriptions of

924-467: The seniority and rate of pay for the writer. For example, a writer credited as a "co-executive producer" will typically receive a higher salary and be considered more senior than a writer credited as a "producer", who will in turn be higher "ranking" than a writer credited as "co-producer." Screenwriters or scenarists or scriptwriters create short or feature-length screenplays for films and television programs. In television and live event production,

957-408: The strike instead of direct current (DC). When using a DC powered strike, the sound is almost imperceptible. There are many manufacturers of electric strikes, and there are many things that have to be considered when buying one, i.e., type of jamb, type of locking hardware, whether one requires fail-secure, fail-safe or hold-open function, length of the latch, depth of jamb, voltage requirements and

990-415: The system could not choose whom to talk to. He would communicate with the same person or group of people until the system was manually reconfigured to allow communication with a different group of people. Two-wire routers or source assignment panels were then implemented to allow quick re-routing. This reconfiguration was usually handled at a central location, but because voltage is used on the circuit to power

1023-414: The television world: two-wire party line or four-wire matrix systems. In the beginning, TV stations would simply build their own communication systems using old phone equipment. However, today there are several manufacturers offering off-the-shelf systems. From the late 1970s until the mid-90s, the two-wire party line-type systems were the most popular, primarily due to the technology that was available at

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1056-429: The time. The two-channel variety used a 32-volt impedance-generating central power supply to drive external stations or belt packs. This type of format allowed the two channels to operate in standard microphone cable, a feature highly desired by the broadcasters. These systems were very robust and simple to design, maintain and operate but had limited capacity and flexibility as they were usually hardwired. A typical user on

1089-440: Was very expensive to implement. It usually required a large footprint in the physical television studio , thus was only used at very large television stations or television networks . For installations where it is not desirable or possible to run wires to support an intercom system, wireless intercom systems are available. There are two major benefits of a wireless intercom system over the traditional wired intercom. The first

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