TV-SAT, CCTV, WLAN Dipol Weekly Review

When a magnet acts like graphene.

Researchers at the University of Illinois have made a discovery that could have a significant impact on the development of electronics. They have found that magnetic materials can be designed in such a way that the spin waves behaving in them resemble the movement of electrons in graphene.

Graphene is one of the best-studied two-dimensional materials. Electrons move in it in a very unusual way - a bit like waves without mass. This gives graphene unusual electrical properties and has been of great interest to scientists for years. The researchers tested whether a similar effect could be achieved in magnetic materials. To do so, they analysed a very thin layer of magnet in which a regular arrangement of tiny holes had been made. These holes were arranged in a hexagonal pattern resembling the structure of graphene.

Such a structure forms a so-called magnonic crystal. In such a material, spin waves propagate - these are minute perturbations in the ordering of the microscopic 'mini-magnets' of which the material is constructed. The way these waves propagate depends on the shape and structure of the material.

Calculations have shown that, in such a designed structure, spin waves behave in almost the same way as electrons in graphene. In other words, under certain conditions they can act as massless particles - something previously associated mainly with graphene and similar materials.

Moreover, the magnetic system turned out to be even more complex than graphene. Instead of two energy levels, as many as nine appeared. This is due to additional properties related to magnetism and to the more complex structure of the material. Some of these levels correspond to waves moving freely, others are more 'trapped' in one place, and still others have so-called topological properties - meaning that they can propagate stably in one direction and are immune to interference or minor damage to the material.

This discovery may have practical applications in microwave technology, which is used in cellular networks and wireless systems, among others. Spin waves can carry radio signals at microwave frequencies. If such materials can be designed well, they could replace some of the traditional electronic components. An example is so-called microwave circulators - devices that allow a signal to pass in only one direction. At present, these are relatively large, but with magnonic materials they could be reduced to even micrometre size. This could lead to smaller, more energy-efficient radio devices.

The research team has already applied for a patent related to this idea. For now, however, it is an important step in understanding how electrons and spin waves can behave similarly, even though they are completely different physical phenomena. Only the coming years will show whether magnonic technology will indeed find widespread practical application.

How to extend and split the PoE power supply?

The PoE extender is a device used in Ethernet networks that allows to extend the range of data transmission and PoE power supply in a single LAN cable. It allows to connect devices such as IP cameras, Wi-Fi access points or other network equipment in a location away from the main network device, such as a PoE switch or NVR. In a standard Ethernet installation, the maximum length of a single cable is approximately 100 metres. The PoE extender is installed along the cable route and acts as a regenerator of signal and power, which it passes on to the next section of cable. This allows the distance between devices to be extended without the need to supply additional power.
A second application is the extension of an existing system with additional cameras in a location where only one network cable is laid. At such a point, an extender can be used to connect several LAN devices.

For such installations, it is very important to check and count the current balance (power balance) of the entire PoE line. This makes sure that the amount of power supplied by the switch port is sufficient to power all the devices at the end of the installation.

In the case as in the diagram above, all devices are operating in IEEE 802.3at. Approximately 30 W is therefore available on the switch port. After the first 100 m of cable, cable losses occur. These are usually around 2-3 W at full load. Around 27 W therefore reaches the intermediate device. An extender or small PoE switch needs some energy for its own operation. This is usually around 2 W. After it has been powered, around 25 W remains.
After another 100 m of cable, losses of around 2-3 W occur again. This leaves roughly 22 W of available power at the end of the line. 2 W is consumed by the next extender - so 20 W are available for the cameras. This is enough to connect 2 - 3 cameras.

Pass-through RJ-45 connectors.

The Dipol range includes EZ RJ-45 category 5e J2012_100 and category 6 J2013_100 connectors. Their distinguishing feature is a through-hole on individual wires ensuring faster and more efficient crimping of the connector. The connector should be crimped and excess stranded wires cut off with the dedicated crimping tool E7914.

RTV/SAT signal in optical fibre - simple distribution from multiple sources.

In the case of an installation comprising two satellite positions (e.g. two satellite dishes) and terrestrial signals - radio and DVB-T2 - all that is needed to convert the signal to optical fibre is one optical transmitter. DIPOL offers professional solutions for distribution of RTV/SAT signals in optical fibre, based on SIGNAL PROfessional equipment. One of the key elements of such a system is the TR-901 SIGNAL PROfessional R69956 optical transmitter, which enables the conversion of RTV/SAT signals into optical fibre transmission.

The TR-901 R69956 transmitter has an optical output with SC/APC connector and can distribute the signal to multiple receiving points - up to 16 optical receivers (REC-109 R69958). On the receiving side, the signal is converted back to the classic QUATRO and radio/DVB-T2 outputs for further distribution in a standard multiswitch installation. Such a solution simplifies cabling, increases the range of the installation and allows for easy expansion of the system with additional reception points.

RTV/SAT distribution in optical fibre is a solution particularly recommended for large houses, multi-family buildings, hotels and commercial facilities where stable and high-quality transmission of TV and radio signals is required.

Connecting a bell button to a Hikvision IP video door entry monitor.

Connecting a bell button to a Hikvision IP video door entry monitor is possible on models with alarm inputs and outputs, such as the DS-KH6320-WTE1 G74001. When a button is connected to the relevant alarm input, the monitor can generate an audible signal to inform the user that the circuit has been triggered. This solution is used in situations where, after passing through a gate with a standard gate station installed, the person entering encounters another door that requires manual opening. Pressing the button triggers a signal on the monitor, allowing the occupant to approach the door and open it. This implementation of the installation reduces costs by eliminating the need for an additional door station at subsequent entrances.

To configure the audible indication in the form of a bell on the monitor when an alarm input is triggered, after adding the monitor to the iVMS-4200 application, enter its settings and go to the Intercom → Zone alarm tab. In the Area No. tab, indicate the alarm input, the violation of which will trigger an audible alarm. Under Zone Type, select Door Alarm Switch.

Coloured pigtails with single-mode fibre.

The Dipol company offers sets of coloured fibre optic pigtails which make it possible to terminate a fibre optic line in an aesthetically pleasing way and allow easy identification of individual fibres in a switch, splice tray etc.

There are 12 color variants of pigtails included in the offer, which are divided into 3 groups (4 colors per set):

There are 3 versions of the connector for each color set: SC/UPC (L34171A, L34171B, L34171C), SC/APC (L34271A, L34271B, L34271C), LC/UPC (L34371A, L34371B, L34371C).

How to capture HDMI video on a laptop or phone When installing monitoring systems, set-top boxes or other devices with HDMI output, there is often a problem with fast video viewing. The equipment is sometimes installed in RACK cabinets or in hard-to-reach places, where no monitor is permanently connected. In such a situation, each change of settings or diagnostics requires bringing an additional screen, which is inconvenient and increases working time...>>>more