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

The world's first-ever 4D printer for ceramics.

A research team at City University in Hong Kong (CityU) made a breakthrough advancement in the search for new materials that allowed for the successful implementation of the world's first 4D ceramic printing. The researchers developed novel "ceramic inks," a mixture of polymers and ceramic nanoparticles. So far, the currently used ceramic precursors for 3D printing are difficult to shape, which makes it impossible to produce ceramics of a complex form. The new precursors with the addition of ceramic ink are soft, so that they can be stretched more than three times. With appropriate heat treatment, it is possible to create unusual objects, such as origami.

Ceramic origami imitating Sydney Opera House
(source: City University of Hong Kong)

4D printing is nothing more than 3D printing combined with an additional element - the time as the fourth dimension in which printed objects can re-shape or assemble themselves under external factors, such as mechanical force, temperature or magnetic field. Working on a new technology, the team developed two 4D ceramic printing methods. In the first shaping method, the ceramic 3D printing precursor and the substrate were first printed with a new ink. The substrate was then biaxially stretched and the joints for connecting the precursor were printed on it. The precursor was then placed on the stretched substrate. Thanks to the controlled by the computer processing time and the release of the stretched substrate, the material transformed into the designed shape.

In the second method, the designed pattern was directly printed on the stretched ceramic precursor. It was then released under the control of a computer program and underwent the process of changing shape. Such solutions can be used in many areas, such as the aviation industry. Because ceramic objects are mechanically strong and tolerate high temperatures, ceramic 4D prints have a large potential to be used as components of e.g. propulsion systems in the aviation industry.

Certificate of compliance with standards for standing and server SIGNAL

RACK cabinets. KOMAG INSTITUTE OF MINING TECHNOLOGY in Gliwice, Poland, confirmed the compliance of standing SIGNAL RACK cabinets offered by DIPOL with general safety requirements contained in Chapter II of the General Product Safety Directive (2001/95/EC) of 3rd December 2001 and in the guidelines of the EN 62368-1:2015-03 international standard. The certificate applies to 7 models of standing cabinets from 24U do 42U and 6 models of server cabinets, from 24U to 42U. The certificates are available in the cards of the standing and server cabinets.

The list of the certified standing RACK cabinets:

The list of the certified server RACK cabinets:

Multi-system analog Hikvision cameras.

Hikvision 4 in 1 cameras enable the user to select any of four available analog video systems: HD-TVI, AHD, HD-CVI or CVBS. The versatility of the cameras ensures compatibility with all systems available on the market, as well as easy adjustment to the requirements of existing CCTV systems that should be extended or modernized. The legacy CVBS mode allows for connecting the cameras to older DVRs that do not support the enhanced video systems. So, it is worth to replace a broken CVBS camera with a multi-system one, with the perspective of changing the old DVR for a new one in the future and switching the new camera to one of the advanced video modes with an increased resolution.

View of a multi-system camera connectors (the cable with the system switch has a yellow label)

By default, the cameras operate in HD-TVI mode. The choice of the standard is made by the micro-switch located on the additional cable. To change a video system to another, the user has to press the micro-switch at least for 5 seconds. The video system switching sequence is as follows: HD-TVI -> AHD -> HD-CVI -> CVBS -> HD-TVI.

Compression connectors in S/MATV systems.

F-type connectors are used for making connections in antenna systems based on coaxial cables with 75 Ω impedance. These are usually terrestrial TV, SAT TV, and CATV installations, and sometimes CCTV systems. The connectors are available in straight and angled versions. Their design and quality have a direct impact on the reliability, stability and performance of the connections - signal loss and impedance matching. The highest quality MASTER compression connectors ensure long-term and reliable operation in even the harshest conditions.

The appropriate design and excellent precision ensure easy installation of the connectors. Precise thread eliminates problems with screwing the connectors on sockets, which can happen with other plugs. The compression method of installation on cables provides high mechanical strength, tightness and stability over time. The straight connectors should be compressed with the E80075 universal compression tool, and the angle connectors with the E80078 tool.

The compressing of the MASTER connectors is shown in this video:

Cost-effective IP CCTV system in a detached house.

The diagram below presents a video monitoring system for a single-family home, based on Hikvision DS-2CD1023G0-I K17661 cameras from EasyIP Lite series, featuring H.265 video compression. The compact cameras have been equipped with 2 MP 1/2.8" CMOS sensor providing good video coverage even in low-light conditions. Along with IR illuminator made in EXIR 2.0 technology providing even lighting with range up to 30 m, they can also operate in complete darkness. The built-in 2.8 mm lens has wide, 103° viewing angle. The video streams from the cameras are recorded by the DS-7604NI-K1/4P K22045 NVR with built-in 4-port PoE switch. Just after connecting the Hikvision IP cameras to the NVR, they are automatically added to the NVR and the images appear on a connected monitor. With the application of the WD Purple M89285 hard drive with 3 TB capacity and thanks to the support for H.265 video compression both by the NVR and cameras, the data retention time exceeds a whole month, even in the case of recording the coverage from all the 4 cameras in continuous mode at 25 fps frame rate. Additionally, the TP-Link C2 N3261 router provides the users with access to the system in the local network and via the Internet. Thanks to the support for Hik-Connect cloud service, they can have access to the system from external networks without problems with configuring network settings. The video from the NVR is displayed on the IIyama 24" M3024 monitor.

Monitoring of a detached house with Hikvision IP cameras.

The order of fibers in optical cables.

Terminating the end of a fiber optic cable with multiple fibers, the installer should pay attention to the appropriate order of the fibers spliced in the distribution frame or installation box. There are several standards addressing that issue, and although there are not general regulations, consistency in this field allows installers to avoid problems in the event of network maintenance or expansion.

Installing optical cabling, it is worth to implement one of the European standards or the proprietary solutions used by cable manufacturers or large telecommunications operators. The table below shows the most common standards for the layout of fibers in optical distribution frames.

It is worth remembering that the adoption of a specific standard saves time and money in the case of expansion of the optical network. Connecting the next links, the installer does not have to empirically verify the order of the fibers in the existing distribution frames and avoids problems with erroneous connections (especially when the splices are placed in closed patch panels without the possibility of viewing the order of the fibers).

Yagi-Uda antennas - from theory into practice. The Yagi-Uda or Yagi antenna is one of the most popular antenna designs. Despite a comparatively simple construction, it has a high gain, typically greater than 10 dBi. Yagi-Uda antennas can operate in the HF to UHF bands (3 MHz to 3 GHz), but often within a limited bandwidth around the center frequency... >>>more

Geometry of Yagi-Uda antennas

Signal Fire AI-8 fusion splicer