Many electronic devices require connections to other devices for input and/or output of power and/or signals. Coaxial cable is frequently used in the delivery of communication signals, including RF, data, video, and audio signals. For example, consumers frequently encounter coaxial cables in conjunction with residential cable television service applications (e.g., set top boxes, television sets, computers, etc.), and industry typically encounters coaxial cables with communication, security, and computer networks (e.g., WANs, LANs, panel boxes, control panels, etc.)
A common configuration of a coaxial cable comprises a center conductor which is typically a solid copper wire, a dielectric insulator which surrounds the center conductor and is typically made of foam or plastic, a shield which surrounds the dielectric insulator and which prevents RF energy from radiating outside the coaxial cable, and an insulating jacket which may be used to protect the other components of the coaxial cable from exposure to harsh weather and/or abusive conditions, and/or to reduce the chance of an electrical shock to a user. Normally, the shield is kept at ground potential and the signal is applied to the center conductor. Although such a coaxial cable may be hard-wired to an electronic device or component, it is more common to connect the cable to the electronic device using connectors, one on the electronic device, and the other on an end of the coaxial cable. In addition to communications signals, a coaxial cable may deliver DC power to or from device circuitry. Typically, but not necessarily, the cable has the male connector and the device has the female connector. One common connector used for connecting coaxial cable 100 to an electronic device is known as a coaxial “F-connector.”
FIG. 1 is an illustration of a conventional cable connection system showing a cable 100, such as a coaxial cable, connected to an electronic device 110, such as but not limited to a cable television receiver, located inside a structure 115, such as a home or building. In many areas the cable 100 is attached to a utility pole 105 for above-ground entry into the structure 115 whereas, in other areas, the cable 100 may be routed below-ground 125 for entry into the structure 115 near or below grade.
Regardless of whether the cable installation is above-ground or below-ground, such cables can carry electrical surges, which are typically caused by, for example but not limited to, nearby lightning 120 strikes, electrical faults, or other events which generate a strong electromagnetic field. Such events can generate surge voltages and currents (referred to herein as a “surge” or “surges”) in ranges which can easily damage sensitive electronic circuitry in devices 110 connected to the cable 100. In the past, attempts have been made to reduce these surges by connecting the cable 100 to, for example, the input of a surge suppressor device (not shown) or an uninterruptible power supply (UPS) (not shown) which includes a surge suppressor, and then connecting the output thereof by a short cable (not shown) to the electronic device 110. The surge suppressor or UPS absorbs or blocks most or all of the surge voltage, depending upon the magnitude of the surge voltage, and the short connecting cable minimizes any surge voltages which might be induced after the surge suppressor or UPS. These conventional surge suppressors and UPS devices can be large, typically require a good connection to ground, require an additional cable, and generally increase the cost and space requirements associated with the electronic device. Furthermore, the level of surge protection provided by such devices is not needed for the most common surges, and the most common surges may be below the amplitude or duration level which triggers the surge suppression feature of such devices but may still be of sufficient amplitude and/or duration to damage the sensitive input circuitry of many electronic devices.