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No. 21/2022 (May 23, 2022)
"Live" lithium batteries.
Researchers at SLAC (Stanford Linear Accelerator Center) and Stanford University have discovered a way to "animate" lithium batteries so that their lifespan will be significantly increased. During a lithium battery's cycle, small islands of inactive lithium form between the electrodes, reducing the battery's ability to hold a charge. However, the researchers found that they could make this "dead" lithium crawl like a worm toward one of the electrodes until it reconnects, reversing the partially undesirable process. Adding this step slowed the degradation of the battery under test and extended its life by almost 30%.
The animation shows how charging and discharging a lithium battery test cell causes an island of "dead" or disconnected lithium metal to move back and forth between the electrodes. The back and forth movement of lithium ions through the electrolyte creates areas of negative (blue) and positive (red) charge at the ends of the island, which swap places as the battery charges and discharges. Lithium metal accumulates at the negative end of the island and dissolves at the positive end. This constant growth and dissolution causes the back and forth movement seen here. Researchers at SLAC and Stanford found that adding a short, high-current discharge step immediately after charging the battery causes the island area to grow toward the anode, or negative electrode. Reconnecting to the anode brings the dead lithium in the island back to life and extends battery life by nearly 30%.
A great deal of research is currently being done on ways to make batteries that are lighter in weight, longer in life, safer, and charge faster than the lithium-ion technology currently used in cell phones, laptops, and electric vehicles. Particular emphasis is being placed on the development of lithium-metal batteries, which can store more energy per volume or mass. In electric cars, for example, next-generation batteries could increase mileage per charge and take up less space in the trunk. Both types of batteries use positively charged lithium ions that move back and forth between electrodes. Over time, some of the lithium metal becomes electrochemically inactive, forming isolated islands of lithium that no longer connect to the electrodes. This results in a loss of capacity and is a particular problem with lithium-metal technology and fast-charging lithium-ion batteries.
Control panel for Protect DVRs.
When choosing an installation location for mobile DVRs, both safety (inaccessibility) and practical considerations must be taken into account. Therefore, DVRs are often installed, for example, in the trunk of a passenger vehicle or in other inaccessible and invisible places. In this case, the problem is the control and operation status of the DVR. The dedicated Protect LED KL-1 M80103 control panel is used for monitoring the condition of the DVR (6 LEDs) and serves as IR extender.
Kl-1 with LEDs
The M80103 panel is placed on a 4-meter-long cable and terminated with a 4-pin connector. It is compatible with Protect 115 M80115 and Protect 116 M80116 DVRs – for these DVRs, it is necessary to cut off the panel's factory connector and manually make the connection with the corresponding DVR connectors. See the connection diagram below:
| KL-1 LED panel cable | DVR connector |
| White | RS485B |
| Red | 12V OUTPUT |
| Green | RS485A |
| Black | GND |
View of PROTECT LED KL-1 M80103 control panel with properly made connector for connecting to DVR
Protect M80218 has a ready-to-use connector, as shown in the picture below:
Signal T2-MINI DVB-T2 HEVC – ideal solution for hotels.
At present, the most popular TV source used in most guesthouses and small hotels is digital terrestrial television (DVB-T). Reception of digital terrestrial television does not require any license agreements with broadcasters or any broadcasting fees. The only fee the hotel is obliged to pay is the so-called subscription fee, i.e. a tax for owning a TV set or a radio collected by the Polish Post Office. Unfortunately, not every TV set is capable of receiving DVB-T2/HEVC standard. DIPOL offers an easy to implement and economically optimal solution to this problem. One of the interesting solutions are DVB-T2 Signal T2-MINI A99313 receivers dedicated for hotels.
The Signal A99313 receiver mounted on the back of the TV set using two mounting pads E950230/E950231 and cable clamps E952054. The pads can also be used for neat arrangement of the cabling. The receiver installed this way remains 9 mm away from the TV which ensures good ventilation. The total installation height does not exceed 25 mm which makes it possible to easily hang the TV on a wall using any LCD bracket without the risk of damaging the wall or the receiver itself.
The features of Signal T2-MINI receiver that are important for hotel systems:
- Signal T2-MINI is powered with 5 VDC from the TV's USB port. Therefore, turning on the TV also turns the receiver on. This allows the receiver and its connected cabling to be hidden behind the TV. After turning off the TV set the receiver draws no current.
- The remote control supplied with Signal T2-MINI enables the user to control the receiver and the TV set simultaneously (after a simple procedure of programming the remote control). The TV is provided with the ability to turn it on and off, adjust the volume, and change the video input. This avoids the need to use two remote controls. In case you lose your tuner remote control you can buy one for yourself.
- Signal T2-MINI has a Hotel mode function. When enabled, the user can only view the channel list, change the program, change the soundtrack and adjust the volume. All other functions remain locked and require a predefined password to change. The customer, having remote control of the tuner, cannot reprogram either the TV or the receiver.
- Signal T2-MINI enables the export and upload of a list of channels and receiver settings from an USB memory. So all you need to do is just program one receiver, arrange the list of channels according as needed, make a copy of the data and upload it to every other receiver in seconds.
Pairing of door station call button with relay output in Hikvision IP video intercom monitors
. When installing a video-intercom system, it is sometimes necessary to install additional functions to notify the user that someone has pressed the call button on the door station. An example can be installation of the system in a noisy production hall, using it by a deaf person or a need to install signalling outside the house, so that being in the garden you would notice that someone has come. The DS-KH6320-WTE1 video-intercom monitor has two built-in relays that can be activated when the monitor starts ringing after the call button is pressed. These relays can operate in monostable (1-180 s) or bistable mode. The operating time and mode of each relay can be configured individually. For example, one relay can be connected to an buzzer with an operating time of 5 s and another to a visual indicator with an operating time of 60 s. Pairing the relays with a call button can be done using the iVMS-4200 application, after entering the remote settings of the monitor in the tab: Intercom -> Calling Linkage. Select the Enable option and choose the relay output that will be activated at the moment of calling. The relay mode and time setting can be configured directly from the monitor.
The screenshot shows relay 1 paired with a call button.
When the monitor starts ringing, the selected relay is activated.
When the monitor starts ringing, the selected relay is activated.
Building a house? Think of fiber optics.
When designing or building a house, a lot is said about proper planning of cabling for low-current systems. However, laying the right cables outside the house at an early stage is often forgotten. Usually, apart from power cables, these include twisted-pair cables (e.g. for video intercom, surveillance cameras, intelligent house system elements etc.).At the stage of construction works, it is also good to think about burying an optical fiber in the ground, which in the future can be used by the Internet provider. From year to year, the optical fiber infrastructure in less urbanized areas is systematically growing. Hundreds of kilometers of overhead networks are built, owned by municipalities as well as by larger and smaller operators. It is very likely that in the nearest future, if not immediately, the fiber optic infrastructure will be built near the house under construction.
The L79302 ground cable is a cost-effective, reliable and simple solution. Two single-mode fibers in G.657A1 standard will allow to provide Internet and other services.
With the cable buried in the ground, and with a little effort of the service provider, it is possible to avoid running overhead cable over the plot, which not only affects the overall looks, but also has to be laid on the side of the house, on the external facade or already inside the building. Burying the optical fibre in the ground during the construction phase, and bringing it to the multimedia cabinet, which is the meeting point of all cabling, will pay off in the future.
Powering cameras via PoE for 250 m
. The PoE ULTIPOWER 0064afat N29978 switch is a desktop type device that ensures smooth network transmission. It has 6 RJ45 ports supporting automatic connection speed negotiation. Four of them support the Power over Ethernet (PoE). The switch automatically detects PD devices compliant with IEEE 802.3af or IEEE 802.3at and supplies them. This makes it possible to extend the range of the network to locations with no access to power lines or outlets, and where access points, IP cameras, IP phones, etc. have to be located. The maximum total power of the devices supplied must not exceed 65 W.The switch has the Extend mode function (activated by the switch on the enclosure) for PoE powering of devices connected via up to 250-meter section of twisted-pair cable. When activated, the switch on the PoE ports disables auto-negotiation of connection speed and firmly sets to 10 Mbps (the uplink ports continue to operate at 10/100 Mbps).
Sample application of the PoE ULTIPOWER 0064afat 6xFE(4xPoE), 802.3af/at 65W N29978 switch.
 | The TP-Link LS1008G 8xGE N299382 switch is perfect for small, medium community computer networks. It has Auto MDI/MDIX function that allows the installer to forget about the problem of "straight" or "cross" connections. The LS1008G is fully compatible with most network devices such as computers, printers and TVs. The device has many applications and is a great networking solution that can be used in dorms, homes or small businesses. | |
![Coaxial Cable 75 ohm: Tri-Shield DIPOLNET RG-6 Cu Eca class A+ 1.13/4.8/7.0 110 dB [500m]](https://static.dipol.com.pl/images/en/pict/e1215_500_.gif) | Tri-Shield DIPOLNET RG-6 Cu 75 Ohm coaxial cable E1215_500 with A+ screening class and 1.13 mm internal conductor is dedicated for both individual antennas and SMATV systems. It can be used for distribution of DVB-T, FM/DAB, DVB-S/S2 broadcasts (also in multiswitch systems). | |
 | Hikvision iDS-7204HUHI-M1/S(C) M75534 is an 4-channel, multi-system DVR capable of recording video from cameras: HD-TVI, AHD, CVBS and IP. In the standard mode, 4 analog cameras can be connected to BNC inputs and 1 IP camera (up to 8 MP). If an analog channel is unused, disabling it in the menu adds support for a new IP camera. When all analog channels are disabled, 5 IP cameras can be connected. | |
Worth reading
How temperature affects battery operation The nominal operating temperature of maintenance-free batteries varies and, depending on the model, is usually between 20 and 25°C. Working at other temperatures affects their performance.
As the temperature drops, the capacity of the cells decreases, so in winter there are, for example, problems with starting a car engine. However, if the battery is not deeply discharged, low or even freezing temperatures should not damage it. Working at elevated temperatures causes a significant reduction to their service life. This is halved for each sustained increase in temperature of 8°C above the rated value. This means that, for example, a battery with a rated temperature of 25°C operated at 33°C will retain 50%, and at 41°C only 25% of the projected lifetime...>>>more
As the temperature drops, the capacity of the cells decreases, so in winter there are, for example, problems with starting a car engine. However, if the battery is not deeply discharged, low or even freezing temperatures should not damage it. Working at elevated temperatures causes a significant reduction to their service life. This is halved for each sustained increase in temperature of 8°C above the rated value. This means that, for example, a battery with a rated temperature of 25°C operated at 33°C will retain 50%, and at 41°C only 25% of the projected lifetime...>>>more
Emu battery with AGM (Absorbent Glass Mat) technology.
The dark elements are lead plates, while the light ones are glass – fiber layers soaked in electrolyte.
The dark elements are lead plates, while the light ones are glass – fiber layers soaked in electrolyte.
Signal Fire AI-8 AI-9 / AI-8C fusion splicers
