DIPOL Weekly Review – TV and SAT TV, CCTV, WLAN

Effective production of green hydrogen using solar energy.

Engineers at MIT intend to produce completely green hydrogen fuel using a new reactor system powered solely by solar energy. Currently, hydrogen is produced by processes that use natural gas (gray hydrogen) or fossil fuels (coal – black hydrogen, lignite – brown hydrogen) as raw materials. Solar thermochemical hydrogen (STCH), on the other hand, is a completely emission-free alternative, as its production is based entirely on renewable solar energy. Unfortunately, so far existing STCH projects have limited efficiency and only about 7% of the incoming sunlight is used to produce hydrogen. The existing technology for producing green hydrogen has been inefficient and expensive.

The MIT team estimates that the new project represents a major step toward developing solar-generated fuels and allows up to 40% of the sun's heat to be used to produce much more hydrogen. As with other proposed projects, the MIT system would be connected to an existing source of solar heat, such as a concentrated solar power (CSP) plant, an array of hundreds of mirrors that collect and reflect sunlight into a central receiving tower. The STCH system would then absorb the receiver's heat and direct it to split water and produce hydrogen. This process is far different from electrolysis, which uses electricity instead of heat to split water. The system, as a whole, resembles a train of box-shaped reactors moving along a circular track. In practice, this track would be arranged around a solar heat source, such as the CSP tower. Each reactor in the process train would contain metal undergoing a redox process, or reversible rusting. Each reactor would first pass through a hot station, where it would be exposed to solar heat of up to 1,500°C. This extreme temperature would effectively pull the oxygen out of the reactor metal. The metal would then be in a "reduced" condition, ready to take oxygen from the vapor. For this to happen, the reactor would be moved to a cooler station at about 1,000°C, where it would be exposed to the vapor to produce hydrogen.

To recover most of the heat that would otherwise escape from the system, reactors on opposite sides of the circular track can exchange heat through thermal radiation, where hot reactors cool down while the cold ones heat up. This keeps the heat in the system. The researchers have also added a second set of reactors that circulate around the first string moving in the opposite direction. This outer string of reactors would operate at lower temperatures and be used to remove oxygen from the warmer inner string, without the need for energy-intensive mechanical pumps. These external reactors would contain a second type of metal, which can also oxidize easily. As they circulate, the outer reactors would absorb oxygen from the inner reactors, effectively removing rust from the primary metal without the need for energy-intensive vacuum pumps. The two reactor strings would operate continuously and produce separate streams of pure hydrogen and oxygen. Next year, the team will build a prototype of the system, which it plans to test in concentrated solar power facilities at the laboratories of the Department of Energy, which is currently funding the project.

Is it possible to control the third and fourth door in Hikvision IP video door entry system with one door station?

Depending on the model, Hikvision IP/2-Wire video intercom door stations have up to two relay outputs dedicated to control the wicket and entrance gate. Although an additional DS-K2M061 controller module can be connected to the door stations over the RS-485 bus, this module allows you to replace the second relay output in the door station to increase opening security rather than adding an additional output. A solution to this problem can be use of relay outputs in the video door entry monitor e.g. DS-KH6320-WTE1 G74001 provided that the monitor has been provided with additional cabling for such integration. The monitor has two relay outputs that can be set as mono or bistable. Activation of the outputs from the monitor's GUI and configuration is done in the Settings ->Advanced Settings -> Output Settings tab. The outputs can be set for a specific time (1-180 s) or until they are deactivated by the user. After enabling the outputs, an icon will appear in the main window of the monitor, allowing you to enter the control options. The outputs will also be visible from within the Hik-Connect application.

Verification of fiber macro-bending with the Ultimode OR-20-S3S5-iSMV tester.

ULTIMODE OR-20-S3S5-iSMV L5830 is equipped with 2 lasers operating at 1310 nm and 1550 nm wavelengths. This makes it possible to perform a comprehensive measurement of the optical path. 1310 nm is the basic wavelength at which measurements are made, it allows highlighting problems with fibre positioning (higher attenuation of connectors and splices), while the 1550 nm wavelength can, in turn, reveal problems with cable or fibre bending. It is thus worthwhile to perform measurements for both wavelengths.

Transmission of DVB-S2X/S2/S satellite signals in single-mode fiber.

For a fiber-optic bus, the size of the facility in which the system is implemented is irrelevant. The signal can be transmitted over hundreds of meters or even tens of kilometers without regeneration. For large buildings, this will greatly simplify the backbone of the system. A conventional system, based on copper wires, allows the signal to be transmitted in the trunk line for several tens of meters. This distance can be increased through the use of amplifiers, although this too has some limitations (as well as implementation and operating costs).

The innovative TERRA equipment for TV/SAT systems in multi-family buildings using fiber optic cable and PON (Passive Optical Network) technology is an excellent alternative to typical systems based only on coaxial cables. PON is a technique that uses only passive infrastructure (fiber optic cabling, optical splitters) at the transmitter-receiver section.

Omada SDN network infrastructure management platform.

Omada platform integrates such network devices as access points, switches and network gateways. It provides comprehensive management of the entire network from the cloud level. The system allows you to create a highly scalable network, fully controlled by a single system. This results in seamless wired and wireless connections that are essential in hospitality, education, retail, offices and many other industries.

Benefits of using Omada SDN:

IP network separation at home. The same IP network should not simultaneously contain devices responsible for home security (monitoring, intercom, gate controllers, etc.) and home computer equipment. Separating these devices is one of the factors increasing integrity of the security system...>>>more