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

How to create environmentally friendly electronics?

Researchers at Duke University (USA) have developed a new technology for producing fully recyclable printed electronics that uses materials free of toxic chemicals. Today's electronics typically contain environmentally harmful substances that are difficult to dispose of, thus limiting their reusability. The new technology aims to reduce the environmental impact of electronics and create a more sustainable electronics industry.

Complex electronic chips consist of multiple layers of components that are bonded together to form a single circuit or electronic board. Scientists have developed three carbon-based inks to print electronics: semiconducting carbon nanotubes, conductive graphene and insulating nanocellulose. Previously, scientists had already developed a printing method, but it was not environmentally friendly. The problem was the low viscosity of the carbon nanotubes, and raising the viscosity required the use of strong chemicals or a very energy-intensive process that required heating to high temperatures. The researchers have now developed a cyclic process in which the printed part is washed with water, dried at a relatively low temperature, and then another layer is applied. This allows successive layers to be bonded together in an environmentally friendly manner. The researchers showed that the transistors produced in this way are fully functional and signalled to the rest of the industry that there is a viable way to make some electronics manufacturing processes much more environmentally friendly. They also proved that almost 100% of the carbon nanotubes and graphene used in printing can be recovered and reused. Nanocellulose is made from wood and can simply be recycled or biodegraded, just like paper.

The researchers say that the above-described printing method can be used in the production of other electronic components, such as screens and displays.

Install with DIPOL.

Installers, do you buy from DIPOL? Do you install our products? Take a photo of your projects completed with our products, and in return you will get points to spend on DIPOL gadgets for each described project. For more information about the promotional campaign, visit Install with DIPOL. The following are photos of a TV/SAT system listed in the campaign, completed by MAR-SAT Instalacje from Chrzanów.

Door station for Hikvision IP video door entry system for narrow poles.

DS-KV6113-WPE1(B) G73624 is a compact 1-subscriber door station for the Hikvision IP video intercom system with a built-in MIFARE tag reader. Due to its compact size, this model is ideal for installation in places with limited space, e.g. on narrow columns. The door station is equipped with an infrared illuminator with a range of up to 3 m to ensure visibility at night. It can communicate with the station in a wired fashion using the Ethernet interface or via Wi-Fi in the absence of dedicated cabling. The station is equipped with 1 relay dedicated to wicket control without the possibility of expansion. An unquestionable advantage of this door station is that after connecting to the Internet, operation via a mobile application, such as call forwarding or remote wicket opening, is possible without installing an additional monitor.

Lightning – protection of signal paths – part 2.

During lightning discharges, surges can occur in signal cables, which can cause damage to electronic equipment. Surges are generated within a radius of up to 1.5 km from the point of lightning strike.

NetProtect J2830 lowers the voltage to a safe level in accordance with European standards for this type of equipment thus reducing the number of failures. It requires no power supply and does not cause interference with data transmission.

When protecting devices powered via PoE, it is worth using AXON PoE NetProtector J2836 which contains two transmission paths: data (lines 1-2, 3-6) and power (lines 4, 5, 7, 8). Both paths are protected by surge protection elements that dissipate unwanted charge to the ground, and also protect the lines between each other within a pair of wires. To increase the load capacity of the power path, line 4 is shorted to 5, and line 7 is shorted to 8.

The phenomenon of dispersion in fiber optic transmission.

One of the phenomena having a major impact on reducing the transmission bandwidth and distance of fiber optic cables is a dispersion. It worsens the signal-to-noise ratio and increases the amount of transmission errors. There are several types of dispersion:

Modal dispersion – occurs only in multimode fibers. Due to the fact that each mode traveling in the fiber reaches the receiver at slightly different time, the edges of the pulses at the end of the line are blurred, which forces an increase in the distance between the transmitted pulses and thus a significant reduction of the bandwidth of the transmitted data. Modal dispersion also limits the maximum transmission distance of multimode fibers;

Polarization mode dispersion – occurs in single-mode fibers. The reason is the fact that any fiber core is not perfectly symmetric (its real cross section is not a perfect circle), as well as the refractive index is not isotropic, so the vertical and horizontal polarizations of the mode travel with a slightly different velocities. This phenomenon limits the maximum transmission distance.

Chromatic dispersion – the waves of different lengths reach the end of the waveguide at different moments, which is a major problem in the use of CDWM and DWDM techniques, with transmissions on multiple wavelengths. There are two components of chromatic dispersion, material dispersion determined by the material composition of a fiber, and waveguide dispersion determined by the waveguide index profile of a fiber.

Broken direct access cable – how to repair? The DACs (Direct Access Cables) make a popular group of fiber optic cables that can be laid directly in the ground, without the need for additional protective conduits. These cables are used in practically every kind of fiber optic systems, from local monitoring systems to operator applications, most often as the "last mile" section, i.e. at the direct customer connection. DAC cables can be damaged (ruptured) due to earth works carried out in the area or spontaneous earth pressure (landslides, freezing of the ground) that exceeds strength parameters of the cable. >>>more