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No. 43/2013 (Dec. 23, 2013)
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The next issue of the Newsletter will be published on January 6, 2014.
The era of high-speed computers.
A group of scientists from the Australian National University developed the first miniature lasers operating at room temperature. The solution based on nanowires made of gallium arsenide is, according to the researches, paving the way for faster and lighter electronics over the next 15 years.The originators claim that the new technology will lead, among other things, to much faster and smaller computers. Light, being the data carrier, is moving faster than electrons, allowing for sending and processing similar amount of data in less time.
The nanowires grown by crystallization of gallium arsenide on a gold substrate
(source: Australian National University)
(source: Australian National University)
The micro lasers are built with nanowires with a diameter of several nanometers. The nanowires are produced through chemical reactions. A specific substrate coated with gold particles is placed in a gas containing arsenic and gallium. By increasing the substrate temperature to 750 °C, the nanowires begin to crystallize and grow up like germinating seeds.
The ends of the nanowires operate like little mirrors bouncing light along the wires and amplifying it to the threshold of laser action. Due to the small size of the lasers, they can be quickly switched on and off, and thus are able to process information very fast.
There were similar solutions with nanowires before, but their biggest downside was the necessity to ensure low operating temperatures. The lasers developed by the researchers from the Australian National University can work at room temperature, allowing for applications in a wide range of devices. As usual with innovations, the way from ideas to mass production may take many years, but nanowires will certainly be in the vanguard of modern technology.
What to remember about using mechanical connectors?
The use of mechanical connectors is the easiest way of terminating optical fibers. They are intended for applications in optical distribution frames and boxes inside buildings. It is enough to prepare the fiber properly by cleaving and cleaning. Can the connectors be used in each case?Properly installed high-quality mechanical connector can achieve the same level of attenuation as fusion splice pigtail, so installers should not be afraid to use them. The size of mechanical connectors is slightly larger than of factory-made equivalents, so they need suitable space in distribution frames or installation boxes. Mechanical connectors cannot be put into the frames or boxes when the available space does not allow for routing fibers with the preservation of the minimum allowable bending radius. Otherwise, the increased attenuation of optical signals may cause serious problems, including connection loss.
Comparison of a mechanical connector and its factory-made equivalent (pigtail).
In the first case, despite the use of a protective sleeve,
the fiber is fastened only by the clamping mechanism in the connector.
In the first case, despite the use of a protective sleeve,
the fiber is fastened only by the clamping mechanism in the connector.
Mechanical connectors can be installed on fibers/cables with different diameters. The Key Quick series has been designed for diameters of 3 mm / 2 mm / 0.9 mm / 0.25 mm. In the case of the thinnest fiber (0.25 mm), the clamping mechanism cannot fasten the sheath of a universal or outdoor cable carrying the fiber. In this case, we recommend to use a mechanical connector only when the fiber end with the connector can be suitably protected in the frame or box and will be rarely disconnected. Otherwise, the best solution is to apply a mechanical splice and a pigtail.
Satellite TV - one cable, four receivers.
Satellite installations in one-family homes often require to use several cables. This is not a problem when the designer and building company have prepared spare conduits. If not, drilling and hammering walls in existing houses is a nuisance for the inhabitants.Unicable technology helps those who are planning to upgrade an existing installation up to 4 outlets (up to 4 single-tuner receivers), or want to replace a single-tuner receiver/s for increasingly more popular PVR receiver/s (Personal Video Recorder) with 2 tuners (each of them requires additional cable from the LNB).
The application of Inverto BLACK Unicable LNB A98240 with UNICABLE output allows for independent reception of satellite channels on four satellite receivers supporting Unicable standard. The signals are provided to the distribution point with a single coaxial cable. From this point, the signals are split into two, three or four signal paths via satellite splitters. It is worth paying attention to the proper selection of these elements - the operating frequency band (5-2400 MHz) and the ability to transfer DC voltage from the receivers to the LNB, like the 1F> 2F splitter Signal R85122.
How does it work? Unicable LNB can receive four signals of different frequencies from different bands/polarizations. The signals are amplified by a low-noise RF amplifier. All the signals are shifted to L band and then enter special multiplexer (a kind of multiswitch) and Single Cable Router (SCR). SCR selects the transponder desired by the receiver (user) and shifts it into one of four channels in IF band (channel 1 - 1680 MHz, channel 2 - 1420 MHz, channel 3 - 2040 MHz, channel 4 - 1210 MHz). The signals are combined using RF filters and can be sent via one coaxial cable. The LNB is controlled by Micro Controller Unit (MCU).
Energy efficient UPS units.
The studies of CyberPower company have shown that in so-called normal conditions (88% of the total operating time) typical UPS units in data centers consume about 18% of the supplied power.Such high power loss and the proportional cost of the wasted energy were the reasons for the company to develop and patent solutions reducing energy consumption. Its GreenPower UPS technology is based on the appropriate design of the circuitry so that to bypass AVR regulator and transformer during normal operation. This way, the power consumed by the UPS circuits has been reduced by 75%, which results in significantly lower heat emission and increased lifetime of the units.
Energetic efficiency of UPS units from leading manufacturers as a function of the load.
A clear advantage of CyberPower devices is particularly evident for small and medium loads.
A clear advantage of CyberPower devices is particularly evident for small and medium loads.
DIPOL offers the following GreenPower UPS units:
12 VDC PoE injector.
Cameras supporting 802.3af standard can be powered remotely (typically with 48 VDC) via UTP/FTP cable, the same that transmits data. The power source is usually a dedicated power supply unit with short-circuit and overload protection, e.g. M1890. Can we remotely power e.g. an IP camera that does not support 802.3af standard? It is possible with the use of 12 VDC PoE injectors/adapters, but over distances shorter than in the case of 802.3af standard.
The diagram above shows how to remotely power an IP camera without PoE option via a twisted pair cable. The power source is the original power supply unit (included with the camera - in this example M1820) that can be connected to the AC power network at a distance, using the N9205 PoE adapter. The 12 VDC voltage is injected into the UTP cable and provided to the camera via two twisted pairs.
Due to voltage drop in UTP cables (about 0.1 to 0.2 V per meter, depending on the current consumption of the camera), the output voltage decreases with the increased distance between the power supply and the camera. In the case of popular cameras the maximum length of the cable cannot exceed 25 meters.
Application of a GSM repeater in a single-family house
The list of the system components:
- A741030 - Trans-Data GSM/DCS/UMTS KYZ8.2/9.5 antenna for communication with a base station
- A6765 - GSM Amplifier/Repeater SIGNAL GSM-305 - bidirectional amplification of GSM (EGSM) signals
- A6812 - two-way GSM splitter for connecting two indoor antennas
- A741001 and A741002 - Trans-Data GSM/DCS/UMTS DW3-A and Trans-Data GSM/DCS/UMTS DW3-B indoor antennas used for distribution of the amplified incoming signals and reception of outgoing signals inside the house. The A741001 antenna provides easy fixing to plasterboard or other suspended ceilings, whereas the A741002 antenna is equipped with expansion bolt for mounting it to concrete ceilings (with surface-mounted antenna cable).
 | Broadband Masthead Amplifier ARM-103M R85211 is dedicated for individual antenna installations and small shared antenna systems with up to a dozen or so outlets. The gain of the broadband (87-790 MHz) amplifier increases with the signal frequency, from 7 dB to 11 dB. The amplifier has 3 outputs for direct connection of three outlets for two televisions, or for connection to three networks, each distributing the output signals to several outlets. | |
 | Vandal Proof Camera v-cam 530 M10773 is intended for professional video surveillance systems. Thanks to modern DSP and latest image processing algorithms the camera provides high resolution video (630 TVL in color mode). The enhanced resolution ensures high quality, detailed images. | |
 | Access Point TP-LINK TL-WR840N N3257 is a wireless router using N standard, integrating firewall, access point, and 4-port Fast Ethernet switch. The device has been designed to provide internet connectivity to small and medium businesses, as well as to private users in apartments and one-family homes. The device allows users to easily and quickly create a wireless network and to share Internet connection on multiple computers, with additional protection with the built-in firewall. | |
Worth reading:
How to choose a camera with day/night function? Day/night cameras can provide very good images both in day and night conditions. Without visible light, the scene is illuminated by IR illuminators and the camera switches into B/W mode characterized by increased sensitivity. Cameras, in contrast to the human eye, "see" the infrared radiation, and can effectively use it to render clear images. With sufficient illumination in the visible range, the IR illuminator is switched off, but natural light also contains IR spectrum. It causes problems with white balance - the image does not reflect the actual colors, e.g. black areas are often seen as dark blue, etc. Such behavior of a camera is often treated by installers as a failure. Therefore, in color mode the infrared part of the spectrum must be filtered out... more
Sunell IRC59/21AKDN - high quality camera with mechanical IR cut filter
