There are many kinds of lamps on the market now. When we choose lamps, we often don't know where to start. Which lamp is more suitable for us? Which lamps should be used in different environments? Next, I will give you a brief introduction to some of the more common lamps on the market.
1. Incandescent lamp
The light-emitting principle of an incandescent lamp is to heat the filament to an incandescent state, and use the thermal radiation to emit an electric light source that emits visible light.
It is the kind of light bulb that we used when we were young, which would be very hot to the hand for a long time, and often slammed the filament, which is the incandescent light bulb. Less than 10% of the electrical energy it consumes can be converted into light energy (compared to 2% for ordinary incandescent lamps), while the rest is lost as heat. At the same time, the higher the filament temperature, the faster the tungsten filament evaporates, resulting in a shorter lifespan for most incandescent lamps. Therefore, although incandescent lamps have many advantages - the color light is closest to the color of sunlight, the color rendering is good, the spectrum is uniform and not obtrusive - but the waste of energy is huge. At the beginning, more than a dozen countries and regions have successively released incandescent lamp phase-out plans. my country has also gradually implemented a phase-out plan since 2011. From October 1, 2016, the sale and import of incandescent lamps of 15 watts and above for general lighting are prohibited.
Summary: If you want to use incandescent lamps as a light source, there will indeed be difficulties in purchasing in the future.
2. Halogen lamp
Halogen lamps can be seen as an upgraded version of incandescent lamps. Referred to as halogen bulb or halogen lamp, also known as tungsten halogen bulb, quartz bulb, is a variant of incandescent lamp. The principle is to inject halogen gas such as iodine or bromine into the bulb. At high temperature, the sublimated tungsten filament and the halogen will chemically react, and the cooled tungsten will re-solidify on the tungsten filament to form a balanced cycle to avoid premature breakage of the tungsten filament. . Therefore, halogen bulbs last longer than incandescent bulbs (almost 4 times longer than incandescent bulbs), and because the filament can work at higher temperatures, they get higher brightness, higher color temperature and higher luminous efficiency.
As an upgraded version of incandescent lamps, halogen lamps have all the advantages of incandescent lamps, but halogen lamps also inherit the disadvantages of incandescent lamps: short lifespan (although already longer than incandescent lamps), low luminous efficiency (although already higher than incandescent lamps), In addition, since the halogen lamp is also a heat radiation source, the temperature of the bulb is still very high during the lighting or just after the light is turned off, so it is absolutely impossible to touch it with your hands.
In addition, both incandescent and halogen lamps have small amounts of ultraviolet (UV) and infrared (IR) radiation problems. It is easy to cause facial skin problems, coupled with ultraviolet radiation, it may even lead to extreme conditions such as solar dermatitis.
Summary: If you want to use a halogen lamp as a light source, you need at least UV protection treatment - in short, it is best to have a frosted or partially frosted and UV-resistant glass panel for the light-emitting part of the lamp head.
3. Ordinary fluorescent lamps
The long tubes we used when we were kids were fluorescent lamps, also called fluorescent lamps. The traditional fluorescent lamp is the low-pressure mercury lamp, which uses the low-pressure mercury vapor to release ultraviolet rays after being energized, so that the phosphor emits visible light, so it belongs to the low-pressure arc discharge light source.
Ordinary fluorescent tubes are coated with halogen phosphors and filled with a mixture of argon and krypton-argon. Light colors are: cool white daylight fluorescent tubes, warm white daylight fluorescent tubes. Compared with incandescent lamps, fluorescent lamps do not get hot and have much higher luminous efficiency, but these two types of fluorescent lamps have lower color rendering performance, and the color rendering index R value is less than 40. Much smaller than sunlight, the standard value of the color rendering index R=100. Watch the color of the surface of colored objects, resulting in a color cast. The color is cyan, gray, and the color is dim and not bright. These two kinds of fluorescent lamps are not high-efficiency and energy-saving electric light sources, and do not meet the technical requirements of green lighting.
Summary: Not enough energy saving and environmental protection, it is not recommended to buy.
4, energy-saving lamps (CFL lamps)
The name CFL is widely abused for electric light sources other than incandescent halogen lamps, such as the ubiquitous term "LED CFL". The energy-saving lamp mentioned here is a compact tri-color electronic fluorescent lamp (abbreviated as CFL lamp abroad), which is a compact fluorescent lamp with its own ballast.
In detail, the CFL lamp is a single-ended compact energy-saving fluorescent lamp. The tube, ballast and lamp cap of this type of fluorescent lamp are tightly integrated (the ballast is placed in the lamp cap), and they cannot be disassembled except for destructive blows, so they are called "compact" fluorescent lamps. Since there is no need to add a ballast, and the drive circuit is also in the ballast, this kind of fluorescent lamp is also a self-ballasted fluorescent lamp and an internal start fluorescent lamp. The whole lamp is directly connected to the power supply network through E27 and other lamp holders, which can directly replace incandescent lamps. Most of these fluorescent lamps use three-color phosphors of rare earth elements, so they have energy-saving functions, so they are called "energy-saving lamps". Energy-saving lamps are small in size, save energy than incandescent lamps, and have a longer lifespan than incandescent lamps. However, the disadvantages are also obvious: as a type of fluorescent lamp, mercury is added to the lamp tube. In the absence of a good recycling mechanism at present, the environmental pollution caused cannot be ignored. In addition, the ballast used in energy-saving lamps will generate certain electromagnetic radiation when generating instantaneous high voltage.
Summary: It contains mercury and other harmful substances, which are harmful to the environment and generate certain electromagnetic radiation. It is not recommended to buy.
5, LED lights
LED is the abbreviation of English light emitting diode (light emitting diode). A light-emitting diode is a solid-state semiconductor device that can convert electrical energy into visible light, and it can directly convert electricity into light.
The heart of the LED is a semiconductor chip, one end of the chip is attached to a bracket, one end is the negative electrode, and the other end is connected to the positive electrode of the power supply, so that the entire chip is encapsulated by epoxy resin. The semiconductor wafer consists of two parts, one part is a P-type semiconductor, in which holes dominate, and the other end is an N-type semiconductor, where electrons are mainly. But when the two semiconductors are connected, a P-N junction is formed between them. When the current acts on the wafer through the wire, the electrons will be pushed to the P region, where the electrons and holes recombine, and then emit energy in the form of photons, which is the principle of LED light emission.
Because LED lamps do not generate high heat and convert electrical energy into light energy as much as possible, LEDs are often referred to as "LED energy-saving lamps". When buying energy-saving lamps, be sure to distinguish between two completely different light sources, LED and CFL. Also known as energy-saving lamps, compared with CFL lamps, LED lamps are environmentally friendly and do not contain mercury and can be recycled and reused. This is probably a major driving force for countries to vigorously develop LED lamps. LED lights have many advantages, mainly the following:
①Green environmental protection: small glare, no radiation, no harmful substances are produced during use.
②Long life and stable performance, there are no shortcomings such as easy burning, thermal deposition, and light decay of the filament.
③Multiple transformations: LED light source can use the principle of red, green and blue three primary colors, under the control of computer technology, to produce different colors, intensities and color temperatures.
Summary: There are many advantages, but the disadvantage is that the price is slightly higher than the above-mentioned lamps, but in the long run, the electricity bills saved can also be quickly recovered.
