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From October 1st, the import and sale of ordinary lighting incandescent lamps of 100 watts or more were officially banned, and the incandescent lamp elimination route entered the implementation stage. Here, OFweek Semiconductor Lighting Network edits the advantages and disadvantages of incandescent lamps, energy-saving lamps, fluorescent lamps and LED lamps.
Incandescent incandescent lamps, also known as electric bulbs, work on the principle that electric current passes through the filament (tungsten wire, melting point of more than 3,000 degrees Celsius) to generate heat, and the spiral filament continuously collects heat, so that the temperature of the filament reaches 2000 degrees Celsius or more, and the filament is When it is in an incandescent state, it glows like a red iron that glows. The higher the temperature of the filament, the brighter the light emitted. Therefore, it is called an incandescent lamp. When an incandescent lamp illuminates, a large amount of electrical energy is converted into heat, and only a small fraction (possibly less than 1, not counted) can be converted into useful light energy.
The light emitted by an incandescent lamp is full-color, but the proportion of the components of the various shades is determined by the luminescent material (tungsten) and temperature. The imbalance of the proportion leads to the color cast of the light, so the color of the object under the incandescent lamp is not real enough.
The life of an incandescent lamp is related to the temperature of the filament, because the higher the temperature, the easier the filament will sublimate. The blackening process at both ends of the fluorescent lamp is: the sublimation of the tungsten wire directly turns into a tungsten gas, and the tungsten gas encounters the wall of the lower temperature and condenses on the wall of the lamp tube and becomes black.
When the tungsten wire is sublimated to be thinner, it is easily blown off after being energized, thereby ending the life of the lamp. Therefore, the greater the power of the incandescent lamp, the shorter the life.
Disadvantages:
Incandescent lamps are the least efficient of all powered lighting fixtures. It consumes only a small fraction of the electrical energy, that is, 12-18 can be converted into light energy, while the rest is lost in the form of heat. As for lighting time, the life of such a lamp usually does not exceed 1000 hours.
Fluorescent lamps, also known as fluorescent lamps, work on the principle that a fluorescent tube is simply a closed gas discharge tube. The main gas in the tube is argon gas (also containing æ°–neon or æ°ªkrypton) and the gas pressure is about 0.3 of the atmosphere. In addition, a few drops of mercury are formed to form a trace amount of mercury vapor. Mercury atoms account for about a thousandth of all gas atoms.
The fluorescent tube is a mercury atom that is pressed against the tube, and the ultraviolet light is emitted by the process of gas discharge (the main wavelength is 2537 angstroms = 253710-10 m). Approximately 60 of the electrical energy consumed can be converted to ultraviolet light. Other energy is converted to heat.
The fluorescent lamp emits visible light by absorbing ultraviolet light from the fluorescent material on the inner surface of the tube. Different phosphors emit different visible light. Generally, the efficiency of converting ultraviolet light into visible light is about 40. Therefore, the efficiency of the fluorescent lamp is about 60 @=24, which is about twice that of the same power tungsten wire.
Disadvantages:
The disadvantage of fluorescent lamps is that they are polluted by the production process and after being scrapped, mainly mercury pollution, and not environmentally friendly. As the process improved, the conversion to amalgam mercury was gradually reduced.
The energy-saving lamp is also called compact fluorescent lamp (referred to as CFL lamp in foreign countries), which has high luminous efficiency (5 times that of ordinary light bulb), obvious energy saving effect, long service life (eight times that of ordinary light bulb), small size and convenient use. It works in much the same way as fluorescent lamps.
In addition to white (cold light), energy-saving lamps now have yellow (warm light). Generally speaking, under the same wattage, an energy-saving lamp saves 80 times than an incandescent lamp, and the average life is extended by 8 times, and the heat radiation is only 20. In the non-strict case, a 5 watt energy-saving lamp can be regarded as an incandescent lamp equal to 25 watts, a 7-watt energy-saving lamp is about 40 watts, and a 9-watt is equivalent to 60 watts.
Disadvantages:
The electromagnetic radiation of energy-saving lamps also comes from the ionization reaction between electrons and mercury gas. At the same time, energy-saving lamps need to add rare earth phosphors. Since the rare earth phosphors themselves are radioactive, energy-saving lamps also generate ionizing radiation (ie, radiation nuclear radiation). The uncertainty of electromagnetic radiation on human body damage, and the excessive radiation radiation to the human body is more worthy of attention. In addition, due to the limitation of the working principle of energy-saving lamps, mercury in the lamps is inevitably a major source of pollution. An ordinary energy-saving lamp contains about 5 mg of mercury, which is only enough to be covered with a ballpoint pen tip, but it may cause 1800 tons of water to be contaminated after it penetrates into the ground.
LED (Light Emitting Diode), a solid-state semiconductor device capable of converting electrical energy into visible light, can directly convert electricity into light. The heart of the LED is a semiconductor wafer.
One end of the wafer is attached to a bracket, one end is a negative pole, and the other end is connected to the positive pole of the power source, so that the entire wafer is encapsulated by epoxy resin. The semiconductor wafer consists of two parts, one part is a P-type semiconductor, in which the hole dominates, and the other end is an N-type semiconductor, which is mainly electrons here. But when the two semiconductors are connected, they form a PN junction. When a current is applied to the wafer through the wire, the electrons are pushed toward the P region. In the P region, electrons recombine with the holes, and then the energy is emitted in the form of photons. This is the principle of LED illumination. The wavelength of light, which is the color of light, is determined by the material that forms the PN junction.
Originally used as an indicator light source for instrumentation, LEDs of various light colors have been widely used in traffic lights and large-area displays, resulting in good economic and social benefits. Take the 12-inch red traffic light as an example. In the United States, a long-life, low-efficiency 140-watt incandescent lamp was used as the light source, which produced 2000 lumens of white light. After passing through the red filter, the light loses 90, leaving only 200 lumens of red light. In the newly designed lamp, Lumileds used 18 red LED light sources, including circuit losses, to consume 14 watts of electricity, which can produce the same light effect. Automotive signal lights are also an important area for LED light source applications.
For general lighting, people need a white light source. In 1998, white LEDs were successfully developed. This LED is made by encapsulating a GaN chip and yttrium aluminum garnet (YAG). The GaN chip emits blue light (p=465 nm, Wd=30 nm), and the Ce3-containing YAG phosphor prepared by high-temperature sintering is excited by the blue light to emit a yellow light with a peak of 550 nm. The blue LED substrate is mounted in a bowl-shaped reflective cavity covered with a thin layer of resin mixed with YAG, about 200-500 nm. The blue portion of the LED substrate is absorbed by the phosphor, and the other portion of the blue light is mixed with the yellow light emitted by the phosphor to obtain white light. Now, for InGaN/YAG white LEDs, by changing the chemical composition of the YAG phosphor and adjusting the thickness of the phosphor layer, white light of various colors having a color temperature of 3500 to 10000K can be obtained. The method of obtaining white light by a blue LED is simple in structure, low in cost, and high in technology maturity, so it is most used.
Disadvantages:
LED lights are more expensive than other lighting fixtures. In addition, the LED industry currently lacks uniform standards. The quality of products produced by various enterprises is different. There are still many uncertainties in terms of light efficiency, color rendering and life. But LED technology is also constantly improving. I believe that one day LED technology will definitely It will mature and enter the ordinary people's home.
Analyze the advantages and disadvantages of incandescent, energy-saving, fluorescent, and LED lights