SĂPTĂMÂNALUL DIPOL - TV/SATELIT, SUPRAVEGHERE, REȚELISTICĂ

New solar panels break efficiency record.

The view of solar panels installed on rooftops and large energy farms has become commonplace in many regions around the world. Even in the usually rainy UK, energy derived from solar panels is becoming an important source of electricity. The rise in popularity of the panels is mainly attributed to two factors. The first is that scientists and engineers are working on how to optimize production steps so that billions of solar panels can be produced quickly and at low cost. The second factor is the constant increase in the energy conversion efficiency of PV panels, that is, how much sunlight can be converted into electricity. The higher the efficiency of solar panels, the cheaper the electricity. Currently commercially available solar panels convert about 20 to 22% of sunlight into electricity.

A new study published in the journal Nature found that the future solar panels could achieve efficiencies as high as 34% by using a new technology – tandem solar cells.

Source: Lincoln Electric Systems via Unsplash

Conventional solar cells are made using a single material that absorbs sunlight. Today, almost all solar panels are made of silicon, the same material that microchips are made of. Although silicon is a reliable material, its efficiency is limited to about 29%. To overcome this limitation, researchers have developed cells consisting of two sunlight-sensitive materials stacked on top of each other (silicon and perovskite) to capture more solar energy. With improved sunlight collection, the new perovskite-silicon tandem has achieved a world record efficiency of 33.89%. Perovskite solar materials, which were discovered less than two decades ago, have emerged as an ideal complement to well-established silicon technology. The secret lies in their ability to tune light absorption. Perovskite can capture high-energy blue light more efficiently than silicon. In just 10 years, the efficiency of a perovskite cell (for a single cell in the lab) has increased from 14 to 26%.

SMATV system in monastery buildings.

Energeentech from Chełmno, a company that specializes in photovoltaic systems, turned to Dipol for help in upgrading a SMATV system in a residential facility on the grounds of one of the monasteries in Szczawnica.

Due to the location of the facility in a mountainous area and the associated weak and scattered signal of DVB-T2 digital terrestrial television, in addition to the terrestrial TV antenna, it was planned to use a single Terra headend panel, allowing reception of selected satellite TV channels. The investor with two satellite decoders decided to use them in a SMATV system.

A DIPOL Tri-Digit A2675 antenna equipped with an antenna preamplifier was used to receive DVB-T2 signals in the UHF band. This antenna performs well in mountainous areas due to its high energy gain and wide half-power angle, which allows it to collect also signals reflected from terrain obstacles.

To receive satellite signals, it uses a high-quality DIPOL 120 cm A9682 dish and two A98233 wideband LNBs. The signal from the LNBs (2 satellite positions: Hotbird and Astra) are fed via UV-resistant Triset-113 PE E1017 cable to Terra SRM-544 R80544 dSCR multiswitch. This multiswitch feeds the Unicable signal to a Terra tdx-420 R81618 headend panel and two satellite decoders operating in standard Legacy mode. The signal from the headend panel and the decoders (after passing through the Signal 420 R86700 DVB-T modulators) is summed on the R60103 splitter.

Converted into DVB-T form using the headend and modulators, the satellite signal is combined with the signal from the terrestrial TV antenna on the E2094 splitter, and then let into the MA-075T R81075 broadband amplifier to compensate for the attenuation created when distributing the signal to dozens of terminal outlets.

Diagram of the completed system

The configuration of the entire system did not cause any major issues to the installers. Some difficulty was overdriving the MA-075 amplifier with too high signal power from the headend panel and modulators. However, this problem was quickly diagnosed and solved with digitally configured attenuators on the above-mentioned devices. The Signal ST-5155 R10155 meter was very helpful in properly adjusting signal levels.

SMATV DVB-T2 system.

Owners of newly built hotels and boarding houses, providing the rooms of their facilities with TVs with built-in receivers for digital terrestrial television (compatible with the HEVC/H.265 codec), only need to take care of supplying a signal of the appropriate level to the antenna outlets. This can be achieved by using an amplifier selected according to the level of the signal coming out of the antenna, the size and topology of the system and the number of outlets.

For smaller boarding houses or hotels with a dozen to a few dozen TV outlets and located in areas with good signal, a good choice will be a TERRA channel amplifier.

From the installer's point of view, the most attractive proposal here will be TERRA's PA321TP R82513 or TERRA's PA420T R82516, with the ability to amplify as many as 20 DVB-T2 MUXes. Moreover, they also offer automatic equalization of signal levels for all channels regardless of their level at the input of the device (while maintaining the minimum required for correct signal quality) of respectively: 113 dBμV (for 6 MUXes) – with this functionality, the installer does not have to worry about equalizing the levels of all signals at the input of the system. This means that it is possible to implement a system with a larger number of outlets (about 80, although this number depends on the type and types of passive elements and cabling used in the system) without using additional amplifiers. An alternative option to TERRA amplifiers can be the use of PROFINO Revolution 6711 R89062 amplifier from Johansson or WWK Alpha+ R89864 from Telmor.

Video intercom system for an apartment block.

A diagram of the Hikvision IP video intercom system for a 10-story (40 apartments) apartment block is shown below. Two identical sets of gate/door stations are installed at the gate and entrance to the block which include: main module with a camera (DS-KD8003-IME1/EU G73652), Mifare tag reader (DS-KD-M G73662), keyboard to control the first relay in the station (opening ) the wicket gate and calling individual tenants (DS-KD-KP G73668), and a display module indicating the door station status and allowing to choose s subscriber from the list (DS-KD-DIS G73670). The gate station modules in the fence are enclosed in two surface-mounted frames (DS-KD-ACW2 G74354) with rain shields (DS-KABD8003-RS2 G74373). The entrance gate is controlled by the gate station in the fence (the second relay is built into the main module). The modules at the entrance to the block are enclosed in two flush-mounted frames (DS-KD-ACF2 G74343). The DS-KH6320-WTE1 G74001 monitors are installed in the apartments. The entire network is made of two Ultipower 2224af N29987 24-port switches.

Diagram of a video intercom system for an apartment block

How to connect an IP camera when the network cable is missing? The installation of cameras or other IP PoE devices in places where it is impossible or uneconomical to replace the existing wiring, and only 2 wires are available for transmission and power supply, is possible using special ETH10-2wire-SET J2842 converters... >>>more

The idea of using ETH10-2wire-SET J2842 converters – PoE power and data transmission in 2 wires of the cable

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