Nr. 25/2024 (17.06.2024)

As a way to separate the high-quality silicon in a solar cell from its silver wires, recycling companies use nitric acid and other chemicals. Researchers in China replaced the acids with a molten mixture of sodium and potassium hydroxide (NaOH/KOH), which is highly reactive with any component it comes into contact with. After experimenting with different treatments, the researchers opted for a two-second immersion followed by a bath of up to two minutes in the 200°C mixture. The short exposures allowed the material layers to separate, leaving them largely intact. The heat breaks down the polyvinyl layer, and the highly reactive hydrogen fluoride gas reacts with sodium hydroxide to form sodium fluoride. Once the silicon is etched, the silver wires also loosen and float. The filtration process can concentrate up to 99% of the silver. The aluminum carrier can also be removed with an alkaline water-based solution, leaving a clean silicon wafer. Elements such as tin, copper and lead used in solder oxidize in air and can be recovered in a sodium hydroxide solution. Lead and tin can be separated by electroplating. Adding water to the NaOH/KOH mixture stops the etching reaction. If necessary, the mixture can be concentrated and reused in the next round of recycling. The waste products from the entire process are sodium silicate and sodium aluminate, which are non-toxic and have wide industrial applications.
A life-cycle assessment conducted by the researchers showed that recycling one kilogram of solar panels according to their approach reduced carbon dioxide emissions by 14 kilograms and energy consumption by 220 times.

DIP Switch Access control point Reader
1000 0000 Door 1 Input reader 1
0100 0000 Output reader 2
1100 0000 Door 2 Input reader 3
0010 0000 Output reader 4
1010 0000 Door 3 Input reader 5
0110 0000 Output reader 6
1110 0000 Door 4 Input reader 7
0001 0000 Output reader 8
Addressing readers by means of DIP switches
Connection diagram of DS-K1104MK G75659 reader to terminal block of the DS-K2604T G75018 controller.

Wiring a house for the Internet – part 2 – internal network topology.

In the previous issue of the Weekly Review, we discussed the choice of network cabling in a single-family home. Another important issue is the topology of the network, that is, information on how to run the wires. The optimal solution seems to be to run one cable to each room in the house. It will give you the freedom to choose the location (e.g. of the access point) or to connect two access points without any problems when the range of one device is not sufficient. Note that the WiFi signal must reach devices such as air conditioners, heat pumps (central heating furnaces), recuperators, refrigerators and other devices equipped with WiFi modules. The ability to freely connect a computer or other device to a wired network may also prove important. Keep in mind that some applications may require cable connection for stable operation. This applies, for example, to streaming high-definition video or playing online games. When planning cabling, one should remember that the Internet is used today not only by personal computers. Twisted-pair cables have to be led to the places where TV sets, consoles and home theaters are installed. It is also worth thinking about one socket in the kitchen, bathroom or any other room.
Cabling solution for a home LAN
A twisted-pair cable should be run to each room so that you have the ability to connect a computer, TV or console. On each floor, in key places, it is a good idea to lead a twisted-pair cable to connect access points, so that the entire facility can be covered with a WiFi signal.

Hybrid illuminator in Hikvision TurboHD cameras.

Hikvision analog cameras with hybrid illuminator have the ability to operate in different light modes: with an IR illuminator, white light or in Smart mode. The default setting is Smart mode, in which, in response to a smart event (processed by the DVR), the scene is temporarily illuminated with white light, and after a specified time the camera returns to black and white (IR) mode. For the Smart function to work, the camera must be connected to a Hikvision DVR. Perimeter protection functions such as virtual line crossing detection, entry or exit from a zone with target classification (human/vehicle) must be enabled on the DVR. Thus configured, the device will operate in IR illuminator mode, which is virtually invisible to the environment. When the DVR detects the presence of a person or vehicle, the scene is temporarily illuminated with white light, and after a certain period of time the camera returns to black and white (IR) mode.

If the Smart mode is not suitable, you can also force only the IR illuminator or only the white light to operate at night. These settings are configured directly in the camera menu.
IR illuminator works at night
Object detection turns on white light
IR illuminator turns on
Available Hikvision TurboHD units with illumination working as described:

Fiber optic categories and designations.

When studying fiber optic network design documentation, one will come across many designations for fiber optic cables and fibers. There are several popular styles of fiber naming. Some of them come directly from the designations proposed by standards and recommendations. Others are a confusion of these designations with abbreviated descriptions on the outer sheaths of cables.
The most well-known way of describing fibers comes from a series of recommendations ITU-T (the telecommunications standardization division of the United Nations digital technology agency). This method of naming and categorization (G.65xx) is most often found in catalog data offered by fiber optic cable manufacturers and vendors. On the other hand, designers of telecommunications networks, when describing cabling issues in detail, can use a European standard issued by the IEC to describe fibers – IEC – EN 60793-2-50. According to it, single-mode fibers are category B, while multimode fibers are category A1. Each category, of course, also has subcategories, the equivalents of which can be found in the ITU-T recommendations.
The third and final way is through designations introduced by the company standards of large telecommunications operators. Within their own networks, they may use alternative designations to those proposed by the standards. An example is Orange, which has introduced the "J" category for single-mode fibers, along with the corresponding subcategories.
The designations and characteristics of single-mode fibers used in telecommunications are summarized in the table below:
PN-EN 60793-2-50
Designation Orange


G.652A B1.1 J2A Single-mode optical fibers with non-shifted chromatic dispersion.
G.652B B1.1 J2B Fibers with reduced PMD polarization dispersion compared to G.652A fibers.
G.652C B1.3 J2C Fiber with reduced attenuation compared to A and B fibers in the so-called water peak range (E-band).
G.652D B1.3 J2D Fibers with reduced attenuation in the water peak range as well as reduced PMD polarization dispersion level.
G.653A B2 J3A Fiber with shifted chromatic dispersion. The zero value of chromatic dispersion is near the 1310 nm wavelength.
G.653B B2 J3B PMD polarization dispersion reduced compared to G.653A.
G.655A B4 J5A Fibers with shifted non-zero chromatic dispersion. No requirements for the PMD factor are specified for this category.
G.655B B4 J5B Reduced PMD factor.
G.655C B4_c J5C Reduced PMD factor compared to G.655B.
G.655D B4_d J5D Fibers with shifted non-zero chromatic dispersion and dispersion in the 1530 - 1585 nm range greater than in G.655C fibers, reducing the impact of nonlinear effects on DWDM transmission.
G.655E B4_e J5E Greater chromatic dispersion and with a different spectral response slope than in G.655D.
B6_a1, B6_a2, B6_b3 J7A1, J7A2, J7B3 Fibers with non-shifted chromatic dispersion characterized by increased resistance to macro-bending. Minimum bending radius – A1: 10 mm, A2: 7.5 mm, B3: 5 mm.
For multimode fibers, ITU-T has issued one recommendation – G.651.1, while not proposing a subcategory of these fibers (the recommendation refers to other documents in this regard). The most popular classification of multimode fibers is introduced by the structured cabling standard ISO/IEC 11801. OM1, OM2, OM3, OM4 and OM5 symbols are described in this very document. A much less popularized (but still found) way of marking multimode fibers is included in EN 60793-2-10. These are respectively A1b for OM1 fibers, A1a1 for OM2 fibers, A1a2 for OM3 fibers and A1a3 for OM4 fibers.
Fibră optică de exterior singlemode: DRAKA A-DQ(ZN)B2Y SM (8 fibre G.652D) [1m]
L79508 outdoor cable with single-mode G.652D fibers. Other fiber designation: B1.3 or J2D.

Cum aducem un semnal satelit DVB-S2X/S2/S la un headend montat în camera tehnică al unui hotel?

În cazul traseelor cu fibră optică, dimensiunea unității în care este implementat sistemul este irelevantă. Semnalul poate fi transmis pe sute de metri sau chiar zeci de kilometri fără regenerare. Pentru clădirile mari (hotel, pensiuni), acest lucru va simplifica foarte mult traseul sistemului. Un sistem convențional, bazat pe cabluri de cupru, permite ca semnalul să fie transmis pe câțiva zeci de metri. Această distanță poate fi mărită prin utilizarea amplificatoarelor, deși și aceasta are unele limitări (precum și costurile de implementare și operare). Dacă doriți să transmiteți un semnal satelit pe o distanță mai mare (mai mult de 100 de metri) de la antenă la camera serverului în care este montat headend-ul (cum este cazul în hoteluri mari sau pensiuni), ar trebui să utilizați un traseu de fibră optică.
Diagrama de mai jos prezintă o situație în care semnalul de la convertorul optic este transmis către camera serverului pe o lungime de 150 de metri folosind un cablu de fibră optică.
Exemplu de sistem de fibră optică care utilizează un convertor optic LWO102 4F31 E A3033 cu putere de +4 dBm pentru a distribui semnalele satelitului DVB-S2X/S2/S în fibră singlemode la o lungime de undă de 1310 nm. Utilizarea receptorului optic ORF202 E cu ieșire Wideband A3131 a făcut posibilă conversia semnalelor optice în semnale electrice. O gamă largă de receptoare optice de la TERRA permite implementarea sistemelor TV, precum și a sistemelor hybride, bazate pe multiswitch-uri tradiționale, dSCR/Unicable. Aplicarea multiswitch-ului SRM-522 R80522 care funcționează în tehnologia de bandă largă permite recepția de programe de la orice transponder satelit pentru fiecare dintre cele patru perechi de polarizare/bandă pentru o poziție de satelit. Transmodulatorul tdx-481 FTA R81621 permite conversia semnalelor DVB-S/S2 de la opt transpondere prin satelit la opt MUX-uri DVB-T. Transmodulatorul tdx420c R81619 are slot CI dual și permite conversia semnalelor de la două transpondere DVB-S/S2 la două MUX-uri DVB-T.

Produse noi în oferta Dipol

===Cameră bullet 4 în 1 Hikvision DS-2CE10KF0T-LFS (5 MP, 2.8 mm, 0.001 lx, ColorVu, IR până la 20 m, lumină albă 20 m) M74122 poate funcționa în sisteme HD-TVI, HD-CVI, AHD sau analogic CVBS. Alegerea standardului se face prin microswitch-ul situat pe cablu. Camera generează imagini la o rezoluție de 5 MP. O caracteristică distinctivă este iluminatorul hybrid cu comutare inteligentă, care constă dintr-un iluminator IR și lumină albă. Este posibil să selectați unul dintre cele trei moduri de lumină slabă: IR, lumină albă sau modul inteligent. Camera aare o carcasă bullet cu iluminator IR până la 20 m
Cameră dome 4 în 1 Hikvision DS-2CE78K0T-LFS (5 MP, 2.8 mm, 0.01 lx, microfon, IR până la 40 m, lumină albă 20 m) M74124 poate funcționa în sisteme HD-TVI, HD-CVI, AHD sau analogic CVBS. Alegerea standardului se face prin microswitch-ul situat pe cablu. Camera oferă imagini la o rezoluție de 1080p. O caracteristică distinctivă este iluminatorul hybrid cu comutare inteligentă, care constă dintr-un iluminator IR și lumină albă. Este posibil să selectați unul dintre cele trei moduri de lumină slabă: IR, lumină albă sau modul inteligent. Camera are carcasă dome cu iluminator IR puternic de până la 40 m.

Merită citit:

Cablarea unei case pentru Internet – partea 1 – alegerea cablurilor. Având în vedere dezvoltarea progresivă a tehnologiei, modificările în ofertele furnizorilor de servicii, precum și inovațiile tehnice apărute pe piață, metoda recomandată pentru construirea cablurilor este foarte diferită față de acum câțiva ani. Confruntându-vă cu sarcina de a proiecta cablarea pentru Internet, în timp ce planificați instalarea, trebuie să luați în considerare mai mulți factori care pot influența aranjamentul final al cablurilor. Așezarea unui număr prea mic de cabluri sau alegerea unui tip greșit de cablu poate cauza limite semnificative în viitor. Pe de altă parte, este important să luați în considerare factorul economic și să nu planificați prea multe cabluri care nu vor fi niciodată utilizate. Deci cum cablați corect casa dvs. în prezent...? >>>mai multe
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