Abstract: Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position.

Abstract: Methods and devices for shielding electronic equipment within an enclosure are disclosed. One method includes positioning electronic equipment within an interior volume of a shielding enclosure having an opening providing access to the interior volume, the opening surrounded by an enclosure frame. The method further includes closing a door to the shielding enclosure, thereby closing off the opening, and engaging one or more latches to affix the door in a closed position, the door including a shielding curtain positioned across the opening. The method also includes inflating an inflatable member positioned along a perimeter of the door frame, thereby applying a uniform pressure to the shielding curtain toward the enclosure frame to form a seal therebetween.

Abstract: The present invention relates systems and methods of electromagnetic protection for integrated video and electromagnetic detector security system equipment. A security system configured to be protected from electromagnetic events or attacks includes a quantity of video cameras and a quantity of electromagnetic event detectors disposed at a facility. The system also includes an electromagnetically-shielded cabinet containing computing equipment and a storage media. The electromagnetically-shielded cabinet is configured to receive data from each of the quantity of video cameras and electromagnetic detectors and store the data on the storage media, whereby, in the event of an electromagnetic event, information at the time of the event can be preserved on the storage media.

Abstract: A control device for an electrical protection circuit for use in an alternating current system including a transformer is disclosed. An example system includes a first measurement probe, a second measurement probe configured to measure an electrical property within the electrical protection circuit, and a control module, including a processing device. The control module is configured to monitor a measurement from the first measurement probe and transmit a protection activation control signal to the switch assembly based on the measurement from the first measurement probe exceeding a first predetermined threshold. The control module is also configured to monitor a measurement from the second measurement probe and transmit a protection deactivation control signal to the switch assembly based on the measurement from the second measurement probe satisfying a second predetermined threshold.

Abstract: Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position.

Abstract: Methods and systems are disclosed for wireless communication, and in particular using a coaxial antenna for distributed wireless transmission. In one example, a wireless transmitter is disclosed that includes a radio frequency signal source and a coaxial cable including a near end and a far end. The near end is electrically connected to the radio frequency signal source and configured to receive signals from the radio frequency signal source. The coaxial cable has an inner conductor and an outer conductor. The wireless transmitter includes a shorting connection at the far end of the coaxial cable, the shorting connection electrically connecting the inner conductor and the outer conductor, and a plurality of openings along the coaxial cable spaced at predetermined locations to output signals generated by the radio frequency signal source. The invention can be used for RF attenuation monitoring and/or testing applications.

Abstract: Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit including a DC blocking component positioned between the transformer neutral and ground and one or more switches selectively actuated to form a path between the transformer neutral and ground in the event of unwanted DC current at the transformer neutral. The system also includes a control circuit electrically connected to the protection circuit and positioned to selectively actuate the switches based on observed conditions within the protection circuit. The system further includes a plurality of test connections disposed within the protection circuit and useable to test electrical properties of the protection circuit.

Abstract: Methods and systems for providing electromagnetic protection of optical equipment are disclosed. One assembly includes an optical device and an electromagnetically shielding enclosure including a plurality of shielding surfaces, the enclosure defining an interior volume containing the optical device. The assembly further includes a waveguide beyond cutoff extending through a shielding surface of the electromagnetically shielding enclosure. The assembly also includes a first lens located on a first side of the shielding surface, and positioned and oriented to focus light through the waveguide beyond cutoff. The assembly further includes a second lens located on a second side of the shielding surface opposite the first side, positioned and oriented to receive light transmitted through the waveguide beyond cutoff.

Abstract: Electrical protection devices, such as for use with power systems for overvoltage protection, are disclosed. One electrical protection device includes a first electrical connection, a second electrical connection, a first electrical discharge device, and a second electrical discharge device. The first electrical discharge device includes a first conductive bus connected to the first electrical connection and a second conductive bus connected to the second electrical connection. The first electrical discharge device has a first breakdown voltage. The second electrical discharge device includes a third conductive bus connected to the first electrical connection and a fourth conductive bus connected to the second electrical connection. The second electrical discharge device has a second breakdown voltage.

Abstract: A continuous grounding system for use in an alternating current system including a transformer is disclosed. The system includes a switch assembly connected between a transformer neutral of a transformer and a ground, the switch assembly having an open position and a closed position, the open position disrupting the path through the switch assembly between the electrical connection and the transformer neutral, and the closed position establishing a path connecting the electrical connection to the transformer neutral through the switch assembly, wherein in normal operation of the alternating current electrical device the switch assembly remains in a closed position. The system also includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground.

Abstract: Camera arrangements that can include electromagnetic protection, such as from EMP/IEMI events, is disclosed. One example camera arrangement includes a camera including a viewfinder having a lens, and an electromagnetically shielded enclosure defining an interior volume containing the camera and configured to include at least one opening aligned with the lens. The camera arrangement includes an electromagnetically dampening barrier disposed across the at least one opening, the barrier configured to shield the interior volume of the enclosure from electromagnetic signals while exposing an optical path between the lens and objects external to the enclosure.

Abstract: An electromagnetically shielded enclosure is disclosed. One such system includes a continuously welded shell having a top, a bottom, and a plurality of side walls cooperating to enclose an interior volume, the interior volume sized to receive electronic equipment and allow human entry. The enclosure is constructed from electromagnetically conductive materials and includes continuous welds along seams joining each material. The enclosure includes a sally port located within the enclosure. The sally port includes a first door in one of the plurality of side walls and constructed from electromagnetically conductive materials. The sally port also includes a second door constructed from electromagnetically conductive materials. The sally port defines a secondary interior volume within the enclosure sized to allow human entry through either the first or second door.

Abstract: Equipment and systems for protecting electronics against damage or upsets from electromagnetic pulse (HEMP or EMP), intentional electromagnetic interference (IEMI), and high power RF weapons are disclosed. This equipment can include a shielding arrangement includes a metallic enclosure having an interior volume defining a protected portion and an unprotected portion separated by an electromagnetically shielding barrier, and having a portal providing access to the protective portion and including an access opening, a shielding cover sized to cover the access opening, and an electromagnetically sealing gasket positioned around a perimeter of the access opening. The shielding arrangement also includes one or more filters positioned at least partially within the unprotected portion and along the electromagnetically shielding barrier to dampen electromagnetic signals and/or power signals outside a predetermined acceptable range.

Abstract: Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit including a DC blocking component positioned between the transformer neutral and ground and one or more switches selectively actuated to form a path between the transformer neutral and ground in the event of unwanted DC current at the transformer neutral. The system also includes a control circuit electrically connected to the protection circuit and positioned to selectively actuate the switches based on observed conditions within the protection circuit. The system further includes a plurality of test connections disposed within the protection circuit and useable to test electrical properties of the protection circuit.

Abstract: An electromagnetically shielded power module and data center including such a module are disclosed. In one example, the electromagnetically shielded power module includes an electromagnetically shielded enclosure including a shell and at least one door, the enclosure surrounding and providing electromagnetic shielding for an interior volume. The electromagnetically shielded power module also includes a power delivery control module positioned within the interior volume and configured to monitor filtered power received into the interior volume of the electromagnetically shielded enclosure. The electromagnetically shielded power module further includes a plurality of power distribution units positioned within the interior volume and configured to receive filtered power from the power delivery control module and route power to one or more computing systems.

Abstract: Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One such system includes a plurality of detection components electrically connected to electrical signal lines leading from one or more connection points on a power grid, and a plurality of threshold detectors, each threshold detector configured to compare an incoming signal from a detection component to a predetermined signal having a threshold. The system also includes a controller receiving an output from each of the plurality of threshold detectors and configured to drive at least one external component in response to receiving an indication from at least one of the plurality of threshold detectors of a detected signal above a threshold.

Abstract: Methods and systems for providing electromagnetic protection of optical equipment are disclosed. One assembly includes an optical device and an electromagnetically shielding enclosure including a plurality of shielding surfaces, the enclosure defining an interior volume containing the optical device. The assembly further includes a waveguide beyond cutoff extending through a shielding surface of the electromagnetically shielding enclosure. The assembly also includes a first lens located on a first side of the shielding surface, and positioned and oriented to focus light through the waveguide beyond cutoff. The assembly further includes a second lens located on a second side of the shielding surface opposite the first side, positioned and oriented to receive light transmitted through the waveguide beyond cutoff.

Abstract: Methods and systems are disclosed for wireless communication, and in particular using a coaxial antenna for distributed wireless transmission. In one example, a wireless transmitter is disclosed that includes a radio frequency signal source and a coaxial cable including a near end and a far end. The near end is electrically connected to the radio frequency signal source and configured to receive signals from the radio frequency signal source. The coaxial cable has an inner conductor and an outer conductor. The wireless transmitter includes a shorting connection at the far end of the coaxial cable, the shorting connection electrically connecting the inner conductor and the outer conductor, and a plurality of openings along the coaxial cable spaced at predetermined locations to output signals generated by the radio frequency signal source. The invention can be used for RF attenuation monitoring and/or testing applications.

Abstract: The present invention relates systems and methods of electromagnetic protection for integrated video and electromagnetic detector security system equipment. A security system configured to be protected from electromagnetic events or attacks includes a quantity of video cameras and a quantity of electromagnetic event detectors disposed at a facility. The system also includes an electromagnetically-shielded cabinet containing computing equipment and a storage media. The electromagnetically-shielded cabinet is configured to receive data from each of the quantity of video cameras and electromagnetic detectors and store the data on the storage media, whereby, in the event of an electromagnetic event, information at the time of the event can be preserved on the storage media.

Abstract: Camera arrangements that can include electromagnetic protection, such as from EMP/IEMI events, is disclosed. One example camera arrangement includes a camera including a viewfinder having a lens, and an electromagnetically shielded enclosure defining an interior volume containing the camera and configured to include at least one opening aligned with the lens. The camera arrangement includes an electromagnetically dampening barrier disposed across the at least one opening, the barrier configured to shield the interior volume of the enclosure from electromagnetic signals while exposing an optical path between the lens and objects external to the enclosure.