Posts Tagged ‘ cable ’

BNC Connections

Friday, July 8th, 2011

Probably the most common cable joiners in the digital video security systems industry are BNC connections.  BNC connectors are easy to use and ensure a sound, full contact connection.  BNC connections are different than most other single pair wire connectors  (such as RCA plugs, for example) plugs, becuase BNC connections are “locked” in place.  The following article is about the origin and use (including applications) of BNC Connections.

BNC is an acronym for this type of radio frequency connector.  The connector is designed for use with coaxial cable and is generally used for radio, television–including digital video camera security systems, and other radio-frequency applications.

BNC stands for Bayonet Neill-Concelman.  Bayonet (“B”) represents the the type of twist locking system that holds the connectors together.  Unlike RCA plugs that just push together can be subjected to accidental disconnection, BNC connections are locked together in the same twisting lock configuration as that of a gun bayonet.   Generally, BNCs do not become disconnected unless they are purposely untwisted from the locked connection.

The “N” and “C” in BNC stands for the first letters of the last names of the two men that invented the connector; Paul Neill and Carl Concelman.  However, origin for development lies with Octavio M. Salati, a graduate of the Moore School of Electrical Engineering (of the University of Pennsylvania).  In 1945 Salati filed for a patent for a coaxial cable connector that would minimize wave reflection and/or loss (one of the primary attributes of a BNC type connector).

Another feature of the BNC connection is that the connectors are available to match the impedance of the cable they are connecting.  Generally, there are two major types of BNC connections based on impedance, 50 and 75 ohm versions that are used today.

There are also many variations that originated from the BNC design.  These include the SR-50 and SR-75 Russian copies whose dimensions differ slightly from the BNC because of converting the measurements from English (Imperial) units to metric.  There is also a Threaded Niell Concelman or TNC connector that displays superior performance over a BNC for microwave applications.

The BNC connection consists of two separate pieces, the “female” and “male” ends.   These ends are firmly and permanently attached to the shielded coaxial cable.  The male end consists of a center (usually) solid copper core wire with the metal shield or mesh that surrounds the cable completing the single pair wire connection.  The male connector is pushed into the female connector and twisted, making the single pair connection and locking the connection at the same time.

There are also different types of BNC connections based on how the actual connector is attached to the cable or provides adaptation to a BNC connector.  Security Camera King offers a variety of BNC connectors on their on-line store catalog.  They may be found at or by clicking “Security Camera Accessories” the “Surveillance Camera Connectors” on the left hand side of the home page.

Security Camera King offers three different types of BNC connections base on how the connector attached to the cable it is attached to and not the actual connection between BNC pieces themselves.  In addition, more many connectors they offer a single unit price and a 100 unit price.

The first of three is the crimp-on connector.  This connector requires the use of a crimping tool to secure the banded necks of the BNC to the coaxial cable.  They are referred to in our catalog as “2 Piece Crimp-on BNC Connector).  These are fairly easy to work with, and when installed properly, including being crimped properly, these provide a fair to good connection.  This BNC requires the use of a special crimping tool.

The second is the twist-on connector.  They are referred to in the catalog as “BNC Connector Twist-On.”  This BNC connection is easy to install (just twist or screw on the cable ends) and requires no special tools.  These connectors hold fairly well and provide a fair to good connection.  Screwing the connectors onto the cable ends can actually be a little difficult though.

The third type is a compression connector.  They are referred in the catalog as BNC Compression Type Connector.”  These connectors require a compression crimping tool (also sold by Security Camera King) and provide an excellent connection and are easy to work with.

In addition to BNC connections, there are many other adaptor and connector types available for purchase on the Web page listed above.


Home Surveillance Systems

Thursday, March 17th, 2011

Home surveillance systems provide security, protection, and monitoring services that can give you peace of mind and keep your family safe.  These systems are based on digital video and digital data; because of this they have the explicit advantage of sharing the benefits of technological improvements in the personal computing industry.  This means exponentially greater performance at less expensive prices.

Typically, most home surveillance systems are component systems made up of three major components or pieces of equipment; the digital video cameras, the Digital Video Recorder or DVR and one or more monitors.  Digital video cameras may be mounted anywhere that’s advantageous to the user; however, standard applications normally provide for exterior perimeter coverage of the home including entrances, exits, and first floor or ground accessible windows.

Inside the home surveillance system can be “zone” type where coverage is based on specific areas of the home and cameras are normally placed in large rooms, hallways, lobbies, and the like or every room may be equipped with its own camera.  This is really a matter of the user’s preference, as are special use cameras.

Special use cameras on the exterior of the home can include a wide variety of cameras and situations.  For example, outdoor cameras (as well as indoor cameras) can be equipped with infrared illumination and the required electronics so as to provide 24 hour coverage, even in total darkness.

More specific uses for the exterior of the home include gate monitoring, driveway monitoring, garage and other detached building monitoring, pet area monitoring, and entrance monitoring.  These cameras can be standard “wired” types or they can also be wireless where the camera transmits a signal to a receiver that is located close to and cabled with the DVR.

Another useful feature for gate and entrance door cameras is two-audio.  Using two-way audio, the gate camera or door camera can act like a security guard that allows you to converse with whomever maybe at the door or gate before permitting them entry.  Each of Security Camera King’s home surveillance systems DVRs supports two way voice technology.

There are many other uses for exterior home surveillance systems’ cameras that are just too numerous to mention here.  The key point is that with all the basic and optional features that digital video cameras have available to offer; they are so versatile that there is almost no situation where they can’t be used.

In addition, there are probably just as many special uses for cameras inside the home as there are outside.  As mentioned earlier, cameras can come with infrared video capability so that when a room is in total darkness, a clear, crisp highly detailed black and white video can still be created.  These cameras are especially useful as baby monitors.   Placed in the nursery with a full open view of the crib/bed and baby/child, these cameras can monitor the infant all night long without disturbing them.  (The infrared Light Emitting Diodes or LEDs that are used to provide the infrared illumination cannot be seen by the human eye.)

Home surveillance systems for inside the home can also include cameras with motion detectors.  These cameras are connected to an on-board PIR or Passive InfraRed detector that turns the camera on for recording only when motion is detected.  The cameras are useful as alarms as well, for the DVR if so equipped, can be programmed to send and email every time the camera is activated.  Furthermore, these cameras save a tremendous about of DVR hard disk space since they only record when motion is detected.

Another highly specialized use indoor home surveillance systems camera is the hidden or disguised camera.  Modern technology has paved the way for these relatively new cameras.  The units are so small that they can easily be hidden inside other normal working objects.  For example, if you need a camera to monitor your home office while you are away, but feel that a mounted camera may appear obtrusive or aesthetically displeasing, you can use a hidden desk clock camera.  The camera is hidden inside the stylish full operating model of a desk clock.

Security Camera King offers all sorts of home surveillance systems and very competitive prices.  We offer 4, 8, 16, and 32 channel systems that come complete with cameras, cable, connectors, power supplies, and a DVR.  We feature three different types of DVRs; the entry level “Elite Mini,” the full enterprise level “Elite,” and our top of the line “Ultimate.”