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No. 9/2024 (February 26, 2024)
Perfect cushioning is the easy way to safe helmets.
Engineers at the University of Colorado at Boulder and Sandia National Laboratories have developed a new liner design that can withstand large impacts. The study sheds new light on foam, something most people encounter all the time but rarely think about. Foams are soft, porous structures designed to absorb energy during pressure. However, they have a major drawback which is that they curl into a stiff roll when compressed hard. To solve this problem, a group of researchers wrote computer algorithms to help redesign the cushioning materials so that they deform according to a specific pattern.
Testing padding printed on a 3D printer at the University of Colorado Boulder
In testing the new solution, it turned out that the engineered padding was able to absorb 25% more energy than previous solutions. It is small, hollow spaces that give the foam its resilience. When the sponge is compressed, they close up absorbing energy. According to the latest ideas, the padding is made of a network of hexagonal towers or plate lattices that look a bit like honeycombs. Under pressure, the honeycombs deform, creating a wave that effectively absorbs the force of impact.
Using new software, the honeycomb structure was designed and then modified by adding several kinks that resemble bellows in an accordion. These kinks help systematize the structure during deformation, allowing for a much smoother collapse. Using a 3D printer, blocks the size of a small brick were created from a resilient material called thermoplastic polyurethane. They were then compressed using an impact testing machine. The group discovered that its blocks could absorb about six times more energy than standard foams made of the same material and up to 25% more than other honeycomb structures. The structures can be created from different types of materials, ranging from resilient plastics to hard aluminum. To sum up, the helmets mentioned in the title may soon give much better protection than at present.
Connecting two devices with one twisted pair cable.
Note! The following is a last resort solution during installation and should not be considered a standard. In system s with only one twisted pair cable between two points and requiring to connect two devices, e.g. IP cameras, there is the need for appropriate extension of the cable.Below, there is an example how to do such an installation. Data transmission in FastEthernet network (100 Mbps) uses the 1, 2, 3, 6 conductors. Therefore, proper connection of conductors to RJ-45 connectors will allow to connect two devices. It is worth mentioning the PoE power supply which can also be provided on the same pins as the data (the camera has to support 802.3af option A).
Unfortunately, such a solution does not always work due to the length of the twisted pair cable, as well as the need for considerable extension of conductors at the end of the cable. It is an emergency solution when there is only one twisted pair cable available and it is impossible to use a switch (e.g. N29810).
Connecting two devices to one UTP cable
DVB-S2X/S2/S in IP.
With IP-based TV distribution technology, the building where the signal is to be available can be equipped with only a twisted pair cable. In addition to the lower cost of cabling, a number of interactive features are gained, and the channel offering can be customized to meet specific customer requirements. IP streams can be viewed on TVs with built-in IP receivers, or if the TV does not have one, using TERRA R81612 VSA N5 IPTV digital receiver. In addition, free video and audio playback software, such as VLC, can be used to help.
In order to bring the satellite signal to the IP system, you can use:
- IPTV streamer 16xDVB-S2X/S2/S-2xIP sdi416 FTA R81590 with built-in USB TERRA socket - the device allows to convert DVB-S2X/S2/S signal (16 transponders) to IP multicast stream with a maximum throughput of 1.2 Gbps.
- IPTV streamer 8xDVB-S2X/S2/S-IP sdi482C with dual CI slot and USB port TERRA R81594 – the device enables conversion of DVB-S2X/S2/S signal (encrypted channels from 8 transponders) to IP multicast stream with a maximum throughput of 0.6 Gbps.
Thanks to television distribution technology based on IP, the cabling in a building can be limited only to one (data + IPTV) or two (separate for data and for IPTV) UTP/FTP cable(s). In addition to low cost of such cabling, the users get access to additional interactive features, and the programming can be adapted to their specific requirements.
New door station dedicated to support second generation Hikvision IP video door entry systems.
Dipol now offers a 1-subscriber IP Villa DS-KV9503-WBE1 G73615 door station with authentication by PIN, QR code, face and card or key fob operating in Mifare standard (13.56 MHz). Aesthetically pleasing design and high functionality make this station ideal for building systems for single-family houses, villas, offices or apartments. It is the perfect solution for those looking for an elegant door station with high functionality. The station features a 4" IPS-type color touchscreen LCD with 800 × 600 p resolution. Two built-in color cameras with 2 MP resolution provide good image quality and effective face or QR code authentication function. One physical call button allows you to quickly establish a call. Built-in 2 relays allow you to control the gate or entrance gate. An infrared illuminator with a range of up to 3 m ensures proper observation in low light conditions. The door station is equipped with an Ethernet port for power supply and network connection, as well as a Wi-Fi (2.4 GHz) module. Configuration is possible using the iVMS-4200 application or directly after logging in via a web browser. Remote viewing and opening are possible via the Hik-Connect mobile application.
View of the IP DS-KV9503-WBE1 G73615 door station
Causes of problems with starting optical RF/SAT systems.
Fiber optic cables are increasingly used in SMATV terrestrial and satellite systems. Since this type of cabling is still a novelty for many installers, who have been making such systems based on traditional copper cabling for years, they relatively often have problems in getting them up and running. These problems are usually easy to diagnose and eliminate.
The possibility to replace a copper 9-cable trunk line with a single fiber optic cable with a diameter of 3-5 mm is one of the main advantages of using fiber optic cables in SMATV systems.
The following is a list of the most common causes of faults in fiber optic RF/SAT systems:
- cabling problems from excessive attenuation at splices, connectors, cable bends, and the inability to verify this attenuation. It is often the case that the person installing the antenna set and active equipment connects it to the existing cabling. Installation work should start with checking the condition of the cables, particularly since it is often only one or at most a few cables. The attenuation of the cable can be checked with a light source, such as L5819, and an optical power meter, such as L5815.
- using connectors with the wrong type of ferrule cut: APC instead of PC and PC instead of APC. Many installers do not pay attention to the type of connector optical transmitter, meanwhile, depending on the manufacturer and model, they may require connectors with straight ferrule, such as FC/PC, SC/PC (blue connectors) or angled ferrule, such as SC/APC (green connectors). A mistake in this regard, in addition to the risk of damaging the connector at the optical transmitter, results in an increase in the attenuation of the connection by about 4-7 dB, which is often almost half of the total optical power budget.
- too strong a signal at the input of optical receivers. If the optical fiber directly connects the transmitter to the receiver (no splitters), it is necessary to use signal attenuators at the input of the receiver. The power of the optical transmitter and the sensitivity range of the optical receiver vary slightly depending on the make and model of the equipment, so be sure of their values by checking the data in the data sheet.
- incorrect connection of FC-type plugs. During installation, it is necessary to correctly position the plug relative to the socket. There is only one position of the socket and plug at which the guide on the connector enters the indentation in the socket. With any other positioning, the socket and plug do not connect properly, despite the nut of the connector being screwed onto the socket. With incorrect installation, a gap is left between the connector and the socket, which prevents signal transmission. You can read more on this subject here.
- too high or too low a level of RF/TV signal at the input of an optical transmitter. Optical transmitters are usually equipped with an AGC circuit that requires a certain minimum level for its proper operation. Before connecting the signal from the antennas to the transmitter, it is necessary to consult the technical specifications of the transmitter related to the acceptable range of signals at the input.
Fiber optic devices used in optical RF/SAT systems are plug & play units. Careful study of the technical data of the devices and awareness of the problems described above, and how to solve them, guarantees 100% success in the implementation of this type of installation.
![Antenna TRANS-DATA LTE KYZ 10/10 + 20 m cable + SMA [698-960, 1710-2700 MHz]](https://static.dipol.com.pl/images/en/pict/a741024_.gif) | TRANS-DATA LTE KYZ 10/10 antenna + 20 m cable + SMA [698-960, 1710-2700 MHz] A741024_20 is a log-periodic MIMO directional antenna for outdoor mounting, designed to receive and transmit LTE/GSM/3G modem signals. The antenna has 10 dBi gain. It is designed to work with LTE modems, telephones or modems: DCS, LTE, 5G (equipped with two antenna connectors). Operating band: 698-960, 1710-2700 MHz. | |
![Antenna TRANS-DATA 5G KYZ 10/10 + 10 m cable + SMA [698-960, 1710-2700, 3300-3800 MHz]](https://static.dipol.com.pl/images/en/pict/a741027_10_.gif) | TRANS-DATA 5G KYZ 10/10 antenna + 10 m cable + SMA [698-960, 1710-2700, 3300-3800 MHz] A741027_10 is a log-periodic MIMO directional antenna for outdoor mounting, designed to receive and transmit 5G/LTE/GSM/3G modem signals. The antenna has 11 dBi gain. It is designed to work with LTE modems, telephones or modems: GSM, DCS, 3G, LTE, 5G (equipped with two antenna connectors). Operating band: 698-960, 1710-2700, 3300-3800 MHz. | |
 | Hikvision DS-2CD1H43G2-IZ IP Ceiling Camera (4 MP, 2.8-12 mm MZ, 0.005 lux, IR up to 30 m, MD2.0, H.265) K02008 is a Hikvision IP ceiling camera, part of the EasyIP Lite series. The cameras in this series have the basic, most commonly used functions, so they are ideal for most systems where stable and trouble-free operation is required. The camera has the motion detection 2.0 function which eliminates false alarms by filtering out human/vehicle type objects. It is equipped with a 4 MP and 1/3” CMOS sensor and an IR illuminator based on EXIR technology with a range up to 30 m to ensure proper visibility in low-light conditions. It has a varifocal 2.8-12 mm Motozoom type lens, enabling remote viewing angle change in the range 96° – 29.2°. | |
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