TV-SAT, CCTV, WLAN Dipol Weekly Review

Ecological perovskites getting closer to commercialisation.

Researchers at the University of Queensland have developed an industrially compatible method to produce lead-free perovskite photovoltaic cells for indoor lighting, eliminating the need for toxic lead and hazardous solvents that have previously limited the commercialisation of this technology. The team's key achievement was the development of a vapour phase evaporation process that enables the formation of high quality lead-free halide perovskites with a controlled intermediate phase, significantly reducing structural defects affecting energy conversion efficiency. The new technology uses intermediate phase engineering to stabilise the crystal structure during material deposition, resulting in homogeneous perovskite layers with high purity and optimised morphology. This process allows precise control of the crystallisation kinetics, which is crucial in the case of lead-free perovskites, as these materials are more prone to defect formation than their lead counterparts. The use of the evaporation method, rather than traditional wet solvent processes, allows for the full elimination of toxic substances while increasing compatibility with existing production lines used in the photovoltaic and electronics industries.

The developed cells achieved an energy conversion efficiency of 16.36% when illuminated indoors, the highest to date for lead-free perovskite cells produced by evaporation. The technology can efficiently absorb the low-intensity light typical of LEDs and fluorescent lamps, making it ideal for powering low-power devices such as environmental sensors, wearables, health monitoring systems or electronic shelf labels used in retail. An additional advantage is that the panels can be manufactured on flexible substrates and in a variety of shapes for easy integration into consumer and industrial products. The next step in the development of the technology is the development of an effective encapsulation to protect the material from moisture and oxygen, which is crucial for the long-term stability of perovskites. According to the research team, the first commercial applications of perovskite internal panels and devices integrated with the technology could appear on the market within the next few years.

Can G.652.D optical fibres be spliced with G.657.A1/A2 fibres?

In optical fibre installation technology, there can be cables containing fibres in different standards. In LAN, CCTV, automation or FTTH installations, one encounters fibres in the G.652.D, G.657.A1 or G.657.A2 standard. The G.652.D standard has been used in telecommunications for over 20 years. The G.657.A fibre group, due to its better mechanical capabilities (smaller minimum bending radius), was originally intended to be used for last mile sections in FTTH networks. The popularity of cables with these fibres means that these fibres can now be found in almost every installation. Installers often ask whether it is permissible to combine (splice) fibres manufactured to different standards.

The unequivocal answer is: “yes”. These fibers have the same physical dimensions (sheath, core) and the same tolerance with respect to the size of the so-called module field diameter (MFD), the area responsible for energy transfer in the optical fiber. Thus, they are 100% compatible with each other, and combining them is allowed as much as possible.

Despite the same tolerance range for MFD size, G.657 fibers (and especially A2 fibers) will generally have a smaller mod field diameter. This means that when measured reflectometrically, the splice of G.652.D and G.657.A fibers will generate high attenuation when measured in the A->B direction and a slight apparent gain in the B->A direction. Such measurement results often combined with an ambiguous-looking fiber splice location on the splicer screen (a dark vertical line at the splice location) lead to erroneous conclusions that fiber splicing in different standards is not appropriate. However, it is important to know that the phenomena observed on the OTDR and splicer screens are apparent phenomena that, as a rule, do not affect the proper attenuation of such a splice.

Mounting SIGNAL PRO multiswitches in a telecommunication cabinet.

Multiswitches of the SIGNAL PROwww.dipolnet.com/7025.htm?attr-1796[1]=30119*** are devices designed for distribution of satellite and terrestrial signals in SMATV systems. For their proper installation dedicated mounts are used, and one of them is UCH PRO 1 R69985. This bracket enables quick, stable and orderly mounting of two multiswitches in telecommunication cabinets, as well as on flat surfaces in dual-layer system. Thanks to its design, it provides adequate distance between the device and the substrate, improving air circulation and facilitating the routing of coaxial cables. Its rigid construction guarantees stability even with a large number of cables fed into the multiswitches, reducing the risk of stress on the connectors.

Advantages of mounting multiswitches SIGNAL PRO on a bracket:

Economical monitoring with the Hikvision HiWatch series.

The HiWatch series by Hikvision is a cost-effective IP surveillance solution designed for simple, reliable installations in homes, small businesses, offices or service outlets. The devices in this line, both cameras and recorders, offer basic video surveillance features with high compatibility and ease of use. HiWatch IP cameras are available in resolutions from 2 to 4 megapixels, providing detailed images in standard lighting conditions. With built-in IR or hybrid illumination with a range of up to 30 metres, they also enable effective night-time monitoring. The series supports wide dynamic range (DWDR), which helps to improve visibility in scenes with high light contrasts. HiWatch IP cameras and DVRs are supported by the Hik-Connect app and iVMS-4200 software, allowing easy system management and remote viewing from anywhere. Although the series does not offer the advanced image analytics or intelligent features known from Hikvision's more expensive lines, its simplicity, stability and attractive price make it the optimal choice for users who want an efficient and affordable IP surveillance system without unnecessary extras.

The diagram above shows a monitoring system for a single-family home built using HiWatch IP cameras SM-IPCB14G-LU K03039 with human and vehicle object filtering. The cameras are equipped with a 4 Mpix sensor and a fixed focal length providing a viewing angle of 98°. This model uses a hybrid illuminator with up to 30m illumination.

The SM-NVR04A-Q1 K22011 DVR was used to record events. A 6-port PoE switch N29978 was used to establish communication between the devices and power the cameras. The DVR uses a 2TB WD Purple M89270 hard drive. Support for H.265 compression by both the DVR and the cameras, allows continuous recording at 20 fps to store recordings for 14 days. To access the system from the local and external network, the DVR was connected to a Mercusys AC12G N2933 router. Locally, the video will be displayed on a Hikvision DS-DS-D5022F2-1V2S M29120 monitor. With Hikvision devices supported by the Hik-Connect cloud, gaining access from the external network is extremely easy and does not require advanced networking knowledge.

HDMI and USB signal transmission in optical fibre.

In situations where the DVR is to be viewed and controlled from a remote room (e.g. surveillance centre), there is a need to transmit HDMI and USB signals. In cases where the cable distance does not exceed 100 m, the H3613 converters can be used and connected by means of an ordinary CAT 5e twisted-pair cable.

In situations where devices up to 200 metres away need to be connected, an intermediate active device such as switch N29915 should be used. However, even at such distances it is better to use media converters and a fibre optic cable. The maximum fibre optic cable length depends on the media converters used and can be up to 40 km.

Conversion of TV light-copper signal using TR-501 optical transmitter. Conversion of TV light-copper signal using TR-501 R69951 optical transmitter is a solution used in modern RTV/SAT installations, especially where long transmission distances, high signal quality and resistance to electromagnetic interference are required. The process begins with feeding electrical signal (RF) from satellite, terrestrial and radio antennas to the optical transmitter, where it is converted into light signal. The TR-501 R69951 transmitter converts signals in the 47-2150 MHz band and uses CWDM technology, which enables the transmission of several wavelengths in a single optical fibre, allowing simultaneous transmission of DVB-S/S2 and radio/DVB-T2 signals...>>>more