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

Dual-function battery.

Researchers at the public Tsinghua University in Beijing, China, have developed a hybrid battery that not only stores and supplies electricity, but also produces valuable chemicals such as furfuryl alcohol and furoic acid (used extensively in industry). Standard batteries, when charged, store electrical energy in the electrodes (lithium ions move from the positive electrode through the electrolyte to the negative one, thus energy is stored in the electrolyte). When the battery is discharged, the direction of ion movement is reversed, thus releasing electrical energy. Another common type of battery is redox flow batteries, which use a reduction and oxidation (oxidation) reaction. Combining the two concepts, researchers have investigated the extent to which such batteries are able to produce additional chemicals while storing or delivering energy.

The breakthrough came in the form of a dual-function metallic catalyst for the anode. Made of a one-atom rhodium-copper alloy, the catalyst seamlessly converts, when the battery is being charged, the furfural contained in the electrolyte into furfuryl alcohol. Furoic acid, on the other hand, is formed when the battery is being discharged. For the cathode, the researchers used cobalt-doped nickel hydroxide, which is similar to the cathode materials used in conventional nickel-zinc or nickel-metal-hydride batteries.

The experiment, the researchers reported, used a set of four hybrid batteries connected in series to power LED lights and smartphones. When the hybrid batteries were charged using a solar cell, they were able to power various devices, including LED lamps and smartphones, while continuously producing furfuryl alcohol and furoic acid. The authors found that the new hybrid battery is comparable to many popular batteries in terms of energy density and power. When storing 1 kWh of energy, 0.7 kg of furfuryl alcohol (a substance used in the manufacture of resins, polymers, wetting and impregnating agents, acid-resistant coatings and cement) is produced. The next-generation battery hybrid concept developed by the team is a giant leap in improving the sustainability and cost-effectiveness of batteries, but further development of the concept is still needed.

SMATV system in a hotel.

Transmodulators that convert the DVB-S/S2 signal to DVB-T COFDM are a popular solution used in many hotels. Satellite channels can be an addition to the terrestrial television programs or be the only part of the package offered. The digital DVB-T COFDM signal available at the output is usually delivered to the end receivers using splitters / splitters.

Key features of TRANS-DATA LTE KYZ 10/10 A741024 antenna:

• Outdoor directional logarithmic antenna,
• MIMO 2x2,
• Multiband: 806-960 MHz, 1710-2700 MHz,
• Multi-standard: GSM, DCS, UMTS, WLAN, LTE,
• Gain:
• 9.5 dBi (806-960 MHz),
• 10 dBi (1710-2700 MHz),
• Short circuit for DC,
• 10 m lead terminated with SMA plug,
• Housing made of durable ABS plastic resistant to UV radiation and weather conditions,
• Mounted to a mast with U-bolts (optionally to a horizontal pipe)

Why multimode fibres?!

Despite the huge popularity of single-mode fiber optics, the multimode fibers are still on the market and are used in selected applications. In theory, the multimode fibers are considered "less future-proof" – on short and medium distances they are not able to match single mode fibers in terms of throughput, while on distances longer than 2 km they are not used at all due to the phenomenon of so called modal dispersion. What is more, it turns out that multi-mode cables, despite their capacity limitations, are more expensive than single-mode cables. This is due to the fact that multimode fiber core, having gradient structure (refractive index changes and is not homogeneous like in single mode fiber core) is more complex and therefore more expensive to manufacture. So why use multimode fibres?

Oddly enough, multimode cabling is often used in server rooms to connect cabinets containing operator equipment. Special lasers and the latest standards of multimode fibers (OM4, OM5) work well there for high throughput transmissions on short distances. Moreover, when extending systems implemented a few or more years ago, installers often decide to use the same type of cabling – there is no point in changing it if it works.

Other reasons for choosing multimode cables include popular opinion that they are easier to splice (due to larger core). This ceased to hold true long ago – in the era of precision core centering splicer, the size the core no longer matters. According to other theories, multimode cables should be used for short distances and single-mode cables for long distances (> 2 km). This is no longer true either in the era when the single-mode devices offered can operate without overdriving on links of any length.

Use of cabling with multimode fibers seems to be reasonable when the system is installed in difficult environmental conditions, e.g. in industrial facilities where there is a risk of exposure to dust or dirt. A larger core of a multimode fiber is beneficial here – the same contamination (see figure above) will have a much greater negative impact on transmission in a single mode fiber (9 μm core) than in the multimode fiber (50 μm core). This difference may not become apparent in fiber splicing, where the operator cares for cleanliness and reduces the influence of external factors. However, it may be important in a switchgear and when connecting, disconnecting or rewiring equipment, if the installer fails to properly clean the ferrule face of the connector.

Power outputs in Hikvision modular IP video door stations.

Following an upgrade of the hardware version of the Hikvision DS-KD8003-IME1(B) G73652 and 2-Wire DS-KD8003Y-IME2 G73646 modular IP video door stations, a 12 VDC power output with a load capacity of up to 0.5 A has been introduced. The solution enables direct powering of the electric door strike from the door station using built-in relays, provided that the electric door strike is powered with DC voltage and current drawn does not exceed 500 mA. If the electric door strike is powered by AC voltage, an additional power supply must be used. When using the power output, we recommend a low-current electric strike, such as Bira's XS00 series.

Installation of TERRA. headend. Devices for LAN, multimedia, CCTV systems are made in such a way that their installation is aesthetically pleasing, and the devices are protected against accidental mechanical damage. Specially designed CD001 R90001 metal housing with DIN rail BD001 mounted on the rear panel is designed for mounting components of the TERRA headend. Combination of the rail and the sheet metal guarantees a rigid mounting of up to 8 devices on a DIN rail...>>>more