Wired intercoms. Two and four wires

Types of connection

Intercoms Wired

While each product line intercom is different, most of the intercom systems analog have a lot in common. Voice signals of approximately one or two volts are carried to the top of a line voltage of dc 12-volt, 30 or 48 that uses a pair of conductors. indications of light signals between stations can be accomplished through the use of additional drivers or can be worn on the torque of the main voice through the tone frequencies sent above or below the frequency range of speech. Multiple channels of simultaneous conversations can be carried on the additional conductors within a cable or frequency or multiplexing time division in the analog domain. Multiple channels can easily be carried by a packet-switched digital signal intercommunication. intercoms laptops are connected using mainly common protected, microphone twisted-pair cabling with XLR connectors 3-pin. Construction and intercoms vehicle are connected in a similar manner with shielded cables often contain more than one twisted pair. intercoms digital use category 5 cable and transmit information back and forth on the data packets using the architecture of the Internet protocol.

Types of Connections

Intercoms Broadcasting two-wire.
Are intercom systems used in tv stations and mobile units, such as those seen at sporting events or entertainment, there are essentially two types of intercoms used in the world of television Systems: matrix two-wire or four-wire. At the beginning, the television stations simply build their own communication systems with an old computer telephony. However, today there are several manufacturers that offer proprietary systems. From the late 1970s until the mid-90s the systems of two threads were the most popular, mainly due to the technology that was available at that time. The variety of two channels used a impedance 32 volts in the generation of the power source is central to advancing the outstation packages or band. This type of format allowed the two channels to operate in a microphone cable standard, a feature highly desired by the bodies of broadcasting. These systems are very robust and easy to design, maintain and operate, but it had a capacity and limited flexibility as they were usually hardwired. A typical user of the system could not choose whom to talk, he communed with the same person or group of people until the system is re-set manually, to allow communication with a different group of people. Routers two-wire or panels of assignment of sources were implemented to allow quick re-routing. This reconfiguration is handled usually in a central, due to which the voltage used in the power supply circuit of the stations of external users, as well as to communicate, so that usually towards a pop when changing channels. Although we could change the channel on the fly, was not generally desirable to do so in the middle of a production, as the noise would distract the rest of the team.

Intercoms Broadcasting to four wire.
The technology of four-wire to the mid-90s he started to gain more importance due to the technology it became ever cheaper and the product smaller. The technology of Four-wire had been present for a while, but it was very expensive to implement, usually required a lot of space in the study, which will only be used in stations very large or television channels.