In the power cord, the light button is a switch, most commonly used to operate electric lights, permanently connected equipment, or electrical outlets. Portable lights such as table lamps may have a light switch mounted on a socket, base, or aligned with the cable. Manually operated on/off switches can be replaced with dimmer switches that allow control of the brightness of the lamp and turn it on or off, time-controlled switches, residential sensing switches, and remote controlled switches and dimmers.
Light switches are also found in flashlights, cars, and other vehicles.
Video Light switch
Wall-mounted switch
Switches for illumination may be in handheld devices, moving vehicles, and buildings. Residential and commercial buildings usually have a wall-mounted light switch to control the lighting in the room. The height of installation, visibility, and other design factors vary from country to country. The switch is often hidden inside the finished wall. Surface mounting is also quite common even though it looks more in industrial and outdoor building arrangements than in commercial homes. The light switch box (the pattress box) has a plastic, ceramic, or metal cover to prevent accidental contact with the live terminal of the switch. Wall plates are available in different styles and colors to blend with the style of the room. They are though quite easy to install.
Maps Light switch
History, culture and style
The first lamp switch to use "quick-break technology" was invented by John Henry Holmes in 1884 in the Shieldfield district of Newcastle upon Tyne. The "quick-break" switch resolves the switch contact problem that develops an electric arc every time the circuit is opened or closed. Arcing will cause pitting on one contact and residual buildup on the other, and the useful life of the switch will decrease. Holmes' discovery ensures that contacts will be separated or united very quickly, how much or little pressure the user gives on switch actuators. This "fast-break" action mechanism means that there is not enough time for the arc to form, and the switch will have a long working period. This "quick break" technology is still used in almost every regular light switch in the world today, amounting to billions, as well as in various forms of other electrical switches.
The toggle button was discovered in 1917 by William J. Newton.
As a component of the power cord or home wiring system, the installation of the light switch is governed by a number of safety and standard authorities. In many countries, the standard dimensions of wall mounting hardware (boxes, plates, etc.) may be different. Since the faceplate used must cover this hardware, this standard determines the minimum size of all wall mounted equipment. Therefore, the shape and size of boxes and face plates, as well as what is integrated, varies from country to country.
Dimensions, mechanical design, and even the display of lights generally change slowly over time. Switches typically remain in operation for decades, often changed only when part of the house is reorganized. It's not unusual to see light switches of the past century still in functional usage. Manufacturers introduce new shapes and styles, but for the most part decorations and fashion problems are limited to face plates or wall plates. Even a "modern" dimmer switch with keys for at least forty years, and even in the latest construction, familiar switch and rocker switches dominate.
Orientation
The directions that represent "on" also vary by country. In the US and Canada, usually the "on" position of the toggle switch becomes "up", while in many other countries like UK, Ireland, Australia and New Zealand "down". (In multi-switching, the correspondence between a single switch state and whether the light is on or off depends on the state of another switch [es] in the circuit.)
Design
The switch may be single or double, designed for indoor or outdoor use. Optional extras can include dimmer controls, environmental protection, weather protection and security. In light and commercial lighting systems, the light switch directly controls the circuit that feeds the lamp. In larger lighting systems, such as warehouses or outdoor lighting systems, the required flows may be too high for manual switches. In this system the light switch controls the lighting contactor, the relay that allows the manual light switch to operate at a lower voltage or with a cable smaller than that required in the main lighting circuit.
In the UK, placing 13 BS1363 Amp sockets on the lighting circuitry is not recommended (although not forbidden), but 2 Amp or 5 Amp BS546 is often installed in the lamp circuit to allow free standing lamp control of the room light switch. In homes and homes built in North America, often rooms and bedrooms have sockets for floor or desk lamps.
Internal operation
The switch contacts are under their biggest pressure when opening or closing. When the switch is closed, the resistance between contacts changes from almost infinite to almost zero. At infinite resistance, there is no current flow and no power loss. At zero resistance, there is no voltage drop and no power loss. However, when the contacts change status, there is a brief instant of partial contact when the resistance is not zero or unlimited, and the electric power is converted to heat. If overheating, contacts may be damaged, or even weld closed themselves.
A switch should be designed to make the transition as quickly as possible. This is achieved by the initial operation of the switch lever mechanism which stores potential energy, usually as a mechanical pressure in the spring. When enough mechanical energy is stored, the mechanism in the switch "breaks out", and quickly pushes the contact through the transition from open to closed, or closed to open, without further action by the switch operator. This quick turnover is crucial for long-life switch contact life, as described in the patent of Holmes in 1884.
While the contacts separate, any electrical energy stored in the inductance of the disconnected circuit is disposed as an arc within the switch, extending the transition and exacerbating the heating effect on the contact. Switches are generally rated by currents designed to be violated, under certain voltage conditions and power factors, as these are the most stringent constraints.
The arc that is generated when the open switch erodes the switch contacts. Therefore, each switch has a finite life, often judged on a certain amount of breaking cycle at the specified current. Operations beyond the specified operating capacity will drastically shorten the life of the switch.
To combat contact corrosion, switches are usually designed to have a "wipe" action so the contacts are cleaned. Large switches may be designed with replaceable replacement contacts that close and open before the main contact, protecting the main contacts carrying the current from wear because of the curve. The contact area of ​​the switch is made of a material that retains corrosion and bending.
Many higher current switch designs rely on arc separation to assist in the spread of contact corrosion. Switches designed for current high voltage usage can become unreliable if operated at very low and low voltage currents, since non-conductive oxide layers accumulate without bows to dissolve them.
Two types of sparks may occur during switch operation. At closing, some sparks, such as those from stone-and-steel, may appear as a bit of metal heated by friction into incandescent, melted, and discarded. At the opening, a bluish bow may occur, with a detectable "electrical" (ozone) odor. Furthermore, contacts can be seen to be dark and pitted. Damaged contacts have higher resilience, making them more susceptible to further damage and causing cycles in which the immediate contact can fail completely.
To create a safe, durable, and reliable switch, it should be designed so that the contacts are held together under positive force when the switch is closed. It should be designed in such a way, regardless of how the operator manipulates the actuator, the contact always closes or opens quickly.
In the construction of many small switches, the spring that stores the necessary mechanical energy for the instant action of the switch mechanism is made of a toughened beryllium copper alloy to form a spring as part of contact fabrication. The same part often also forms the body of the contact itself, and thus is the current path. Abusing the switch mechanism to hold the contact in transition state, or overloading the switch, would heat up and thereby twist the spring, reduce or eliminate the "snap action" of the switch, causing slower transitions, more energy dissipated in the switch, and progressive failure.
Variations in design
The push-button switch has two buttons: buttons that close the contact and which open the contact. Pushing the raised button open or close the contact and bring up the previously pressed button so that the process can be reversed. Push-button button reproduction is available on the market today for vintage or authentic style.
Switch
The toggle mechanism provides "snap-action" through the use of geometry "above". The design was patented in 1916 by William J. Newton and Morris Goldberg. The actuator switch does not control the contact directly, but through the intermediate settings of the spring and the lever. Activating the actuator initially does not cause any movement from the contact, which is actually held positively by the spring force. Rotating the actuator gradually stretches the spring. When the mechanism passes through the center point, the spring energy is released and the spring, not the actuator, pushes contact quickly and forcibly into the closed position with an audible "snapping" sound. This mechanism is safe, reliable, and durable, but it produces a hard blip or click.
In 2004 in the United States, the toggle switch mechanism was almost entirely replaced by a "silent switch" mechanism. "Quiet switch" mechanism still has the form of action snap, but very weak compared to its predecessor. Therefore they are equipped with greater contact and high quality that can divert domestic cargo without damage, although the action is less positive.
Illumination Button
The illuminated switch incorporates a small fluorescent lamp or LED, allowing the user to easily locate the switch in the dark. Household lighting switches were introduced in the mid-1950s.
Single-pole dependent switches have the power to energize the built-in source (usually, the "fluorescent" light) of the current through the controlled lamp. The switch works satisfactorily with incandescent lamps, halogen lamps, and non-electronic fluorescent fixtures, since the small currents required for the switching source are too small to produce visible light from devices controlled by an illuminated switch. However, if they only control the compact fluorescent lamp (CFL) and/or LED lights, the small amount of current required to energize the lighting source in the switch also slowly fills the internal input capacitor in the electronic ballast of the CFL or LED until the voltage rises above to the point where it generates a short discharge through the CFL. This cycle can be repeated indefinitely, producing a brief flash of lights over and over (and light inside the switch) while the lit switch is in the "off" position.
Rocker
An alternative design for the toggle switch is the rocker switch. The major switches of this design are commonly known as "decorator styles" in the United States. The switch from this design sits almost flat with a wall plate, and is switched with a "shake" lever that is flat and wide, rather than pushing the prominent actuator short up or down.
In Europe, Hong Kong, Malaysia, Singapore, and India this type is almost universal, and switch-style switching will be considered archaic.
Australian rocker switch
In Australia and New Zealand, a small rocker switch is almost universally used, in the form of a 16 mm (0.63 in) switch mechanism mounted from the rear to the wall plate - attach via lugs mounting, as shown in the photo on the left. a slightly larger "cover plate" supplied with a wall plate, or an addition to it, then clips over the assemblies, as an additional insulating barrier covering the deep wall mounting screw - which is a "deep set" to prevent mismatches the delusion of human contact. The "cover plate" can be removed without the use of equipment, such as when a wall painting is required.
While larger style "decorator" switches are already available in Australia, the advantage of smaller mechanisms is that wall plates are available for installation from one to six individual switch mechanisms, or other similar sized "mechanisms" - such as dimmers and indicator lights - in the same room as one (or two) larger design switches may be installed. Because the mechanisms are small, they can also be mounted onto "architrave" plates, for mounting in positions where it is impossible to install "standard" wall plates. An example is shown in the image below on the right. All switch mechanisms do not have open metal parts requiring grounding. While switches, wall plates, and cover plates from different manufacturers tend not to be interchangeable, this type of switch mechanism has been available in Australia since 1971.
The key module system for the extra low voltage (patented 1995) jack is somewhat similar in appearance to these modules, but the keystone retaining designs are different, and the keystone module can be removed without a tool. (Similar systems, but with larger switches, used in Italy.)
As shown in the disassembly photo, the actuator switch rotates in two holes on the sides of the plastic switch body. An actuator bar slid in two grooves inside the actuator, pressed by the compression spring to the notch in the common contact bar. Common contact rods are free to sway on small diameter rods, welded to public terminals. However, due to the pressure applied by the compression spring, the common contact bar will always be held against one of two contacts.
When the actuator is moved, the mechanical energy is stored in the compression spring until the actuator passes through its center position. At that point, the common contact rod is forced in the opposite direction of the compression springs, acting through the actuator blades, thus disconnecting from existing contacts and making connections with other contacts. Common contact bars are made of copper, with a harder contact metal inlay at the bottom. Although it is free to move the required distance lengthwise, it is restricted from moving sideways by the molded plastic body construction.
Hollow screw terminals and allow up to at least three 1 mm (CSA) cables, twisted together, to fit to a depth of up to 10 millimeters (0.39 inches) and secured with a set screw. The contact terminal set screw is mounted at a slight angle to allow the access of the screwdriver more easily after the switch mechanism is mounted onto the wall plate - before mounting the wall plates to the wall. Also displayed is a "loop" connection terminal. This terminal does not play a part in switch action but, because there is available space, it is provided as an isolated terminal to join other cables, if necessary (such as neutral wires). Each Australian rocker switch mechanism is actually a single, double pole (SPDT) switch, also known as a "two-way switch", and has three terminals.
The switch is basically the same design also used on the wall plates of Australian electrical outlets. It is now very rare to find other types of switches in Australian homes, although the Australian Australian Cable Standard 3112 does not prohibit other types. While many design variations and cover plates of Australia are available, some designers and renovators can import switches designed by the UK and Europe when they want a specific solution. However, while Australian standard wall plates mounting have dimensions similar to those used in North America, they have dimensions that are different from those used in the UK or Europe.
The switches (and other mechanisms) of the Australian design series are currently available in the UK (and other countries), along with wall plates that comply with the relevant mounting standards of the countries concerned.
For a short time, Australian rocker switches were exported to the United States in the 1980s. Although the switches have adequate ratings for use on the 120 V circuit and have a distinct coherence and appearance, they have failed to establish themselves in the American market.
Tamper resistant
If the lighting circuit should not be turned off accidentally, for example, lighting controls of corridors and rest rooms in public buildings such as schools, destructive switches can be installed. This requires a key to operate and thus inhibits accidental or intentional switch operation.
Voltage class
In North America's commercial and industrial lighting installations, lighting installed on 3-phase 480Y/277 V circuits uses a higher voltage than the general 120V switch rating.
Mercury switch
Before the 1970s, mercury switches were very popular. Their costs are more than other designs, but they are completely silent in operation. The switch actuator fills a sealed glass tube connected through a flexible cable, causing a drop of liquid metallic liquid to roll from one end to the other. When it arrives at the end of contact, a drop of mercury bridges a pair of contacts to complete the circuit. Many of these switches are also equipped with fluorescent lights that are connected throughout the contact, and thus in series with the electrical load. This causes the indicator to glow when the switch is turned off, as an aid to find the switch in a dark room.
Although the glass bottle is tightly closed, concerns about the release of mercury are toxic when the switch is finally damaged or discarded causing the abandonment of this design to new products.
Pull-chain or pull-cable
The lamp switch combined with the lamp socket is sometimes installed in the basement or utility area of ​​the house. The switch is operated by a pull or cable chain. It is also possible to have a separate cable switch from the light socket, which is very common in UK bathrooms. Until 2001, British cable regulations required that all bathroom switches be operated by tensile cables.
Dimmer switch
The dimmer switch, called properly dimmer control , contains a solid-state circuitry to allow to change the brightness by reducing the average voltage applied to the lamp.
Electronic switch
In principle, it is easy to design a silent switch in which mechanical contacts do not directly control the current, but only solid-state device signals such as thyristors to complete the circuit. Many variations on this theme have been created and marketed. The "Touch Plate" device can be operated by touching or just waving at hand near the switch. The touch switch has no moving parts and electronically alters the light circuit. In 2006 it remains a special item. Electronic switches provide flexibility in terms of different interfaces for their operations, such as touch plates, soft touch controls, pressure or light sensor-based controls, interactive touch screens (which are widely used in aircraft for lighting control), and more.
Public buildings such as hospitals often save energy by using motion detector switches, also known as occupancy sensors. Residential sensors can also be used in residential applications such as in bathrooms, garages, and alleys.
The wireless light switch provides remote control lighting using a handheld transmitter. While the controlling device may be a dedicated unit for this purpose, the more such switches can be controlled by technology (such as Bluetooth or Wi-Fi) now found in smartphones.
Remote control cable from the lamp switch is also possible using, for example, X10 signal above the power cord.
Multi-path switch
Two or more light switches can be interconnected to allow for lighting control from, for example, two long corridor or landing ends on and down the landing of the ladder. Multiway switching is done using a special switch that has additional contacts.
Materials
The previous switch was made from porcelain in a surface-mounted version and operated as a rotary switch with rotary mechanism. Then, Bakelite is more durable to use. Today they are made of modern plastic. In some cases, especially in hospitals and other public facilities, the exposed part of the lamp switch is made of an antimicrobial material such as copper, for infection control.
See also
- Touch sensitive lights
References
External links
- Media associated with the Light switch on Wikimedia Commons
Source of the article : Wikipedia
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