1 response All of these "stacked cyclindrical discs" are INSULATORS utilized to give enough CLEARANCE and CREEPAGE DISTANCE between high-voltage sections and the ground. The smallest distance in air between two conductors is defined as clearance. Air is an insulator with an insulation value of kV/mm. The larger the distance, the more material there is between the conductor and the ground.
2 responses These are also called "spiral inductors". They are formed by winding a length of insulated copper wire around a cylindrical core. The resulting coil can then be placed in parallel with other coils or coupled to other circuits like transformers. Spiral inductors are used mainly for their shape, which allows them to fit into small spaces. Also, they have very low resistance when compared with other types of inductor.
3 responses These are metal objects shaped like rings or spheres. They work by inducing voltage differences in adjacent parts of a circuit. Power lines are full of these elements to prevent current from flowing through people or animals. They fail if any part of the line falls below acceptable limits for voltage stress.
4 responses These are large metal objects with several loops of wire attached. They work by induction: much like how a transformer works but on a larger scale. A power line carrier operates by having one loop of its own wire act as a primary coil, while another similar loop acts as a secondary coil.
Insulators are used in electrical equipment to support and isolate electrical wires while preventing current from flowing through them. Insulation is a type of insulating material that is used in large quantities to wrap electrical wires or other equipment. It's referred to as insulation. The two main types of insulation are thermal insulation and electrical insulation.
Thermal insulation keeps heat out by preventing conductive and convective transfer of heat through it. Thermal insulation can be solid, like ceramic, or viscous, like rubber. It can also be a gas such as air or krypton. Thermal insulation prevents heat from leaving a zone by blocking its channels through which heat might flow. For example, the channels between stars are too narrow for radiation to travel across the distance between them; thus they remain cold despite the presence of many stars. On Earth, only thin layers of skin cells cover bone because blood vessels in bone are too small to allow heat to escape. Under normal conditions, muscles contract and expand to regulate body temperature. But if you were lying in ice water without any protection from freezing—your only source of heat being your body—you would die before your bones melted.
The electrical industry uses three categories of insulation: thermal, chemical, and electronic.
Electrical insulation comes in three forms: metal-sheathed, paper-sheathed, and fiber-optic cable.
DVD-R discs are constructed of two 0.6 mm polycarbonate layers that are fused together. One of the layers has a grooved reflecting surface as well as a recording dye (thus the somewhat green/blue coloration of DVD-R discs as compared to duplicated discs). The other layer is transparent and is used to generate light through reflection when the disc is played back in a DVD player.
Recording data are encoded in channels along the length of the disc. Each channel is either "on" or "off" (i.e., has one value or the other), so that the information stored on the disc can be read by a special reader called a "disc drive." A typical DVD-R has four data channels, allowing for up to 4 billion combinations of "1"s and "0"s to be recorded. Duplication machines can produce discs with up to 36 channels, which allows for over 1 trillion bits of information to be stored on each disc.
DVD-Rs can store from 20 to 50 GB of data. This means that you can store about six full-length movies on a single disc! The quality of data that can be stored on a disc depends on how fast the laser can write to it. Writing data quickly reduces errors due to dust particles on the disc's surface.
DVD-Rs are non-rewritable; once data have been written to them, they are locked up forever.
In the United Kingdom, pylons are incorrectly referred to as suspension, tension, or transmission towers. To make matters even more complicated, in the United States, "pylons" are traffic cones. The overhead high-voltage cables are supported by porcelain or toughened glass insulators, which keep them away from the unearthed towers. These disks are used as protective covers for the wires while they are not in use.
There are two types of glass insulation: hollow and solid. Hollow glass insulation consists of two parts: a bowl and a stem. The wire is inserted into the stem which is then closed off at both ends. This type of insulation can only support a single conductor. If another conductor is placed inside the same shell, there will be no way to separate them. Solid glass insulation has a base plate and four legs. Each leg is about the size of a pencil lead and they are all stuck together at their bases. One side of the base plate is marked with the voltage being carried by the cable; the other side has an identification number. This type of insulation can support up to four conductors.
The term "glass fiber" is often used interchangeably with "toughened glass". However, glass fibers are simply strands of glass that have been coated with resin; they are not necessarily made of glass filaments (which are thin strips of fused silica).
Pony insulators, which were frequently little more than 3 1/2 inches tall, were used for lower voltage lines, and "power" insulators, which were much bigger and weighed more than 30 pounds, were used for high-voltage lines. The "Signal" variant is the most popular, and it is used for communication and supplementary power lines. This type of insulator can be seen in the photo below.
Power line communications (PLC) use parts of the power grid to transmit data that would otherwise have to be transmitted by means of cables. PLC systems can replace or supplement other types of telecommunications infrastructure technologies such as fiber optics or wireless networks.
The earliest power lines were made from copper wire, but this metal is expensive and vulnerable to corrosion when exposed to weather conditions. So aluminum wire was added to power lines during the late 1940s. Later, plastic insulation was added to power lines as a way to reduce the weight carried by the wires and the cost of maintenance.
Currently, most power lines are made from steel wire with thick layers of insulation attached to them. Some areas of older power lines may still contain copper wiring, however this is very rare because it is so expensive to install.
Power line communications can operate on any voltage up to 400,000 volts, but usually less than 100,000 volts is used since higher voltages are difficult to handle safely. Communication signals are transmitted between base stations that are typically located at least 10 miles apart.