Incandescent lamps are also known as electric bulbs, which work by generating heat when the current passes through the filament (a tungsten filament with a melting point of over 3000 degrees Celsius). The higher the temperature of the filament, the brighter the light emitted. This is why they are called incandescent lamps. When an incandescent lamp emits light, a large amount of the electrical energy is converted into heat and only a very small proportion (probably less than 1%, no calculations) is converted into useful light energy.
The light emitted by an incandescent lamp is panchromatic, but the proportion of the various components of light is determined by the light-emitting substance (tungsten) and by the temperature. The imbalance in the proportions leads to a colour shift in the light, so that the colours of objects do not appear realistic under incandescent light.
The life of an incandescent lamp is related to the temperature of the filament, because the higher the temperature, the easier it is for the filament to sublimate. The blackening process at both ends of the fluorescent lamp is: the sublimation of the tungsten filament becomes tungsten gas directly, and this tungsten gas encounters the lower temperature of the lamp wall and condenses on the wall of the lamp and blackens it. When the tungsten filament sublimates to a relatively thin and thin level, it is easy to burn off when the electricity is applied, thus ending the life of the lamp. So the more power the incandescent lamp has, the more power it has.
Fluorescent lamps
Fluorescent lamps are also known as fluorescent lamps and work on the principle that a fluorescent tube is simply a closed gas discharge tube. The main gas in the tube is argon (also contains neon or krypton) at a pressure of about 0.3% of the atmosphere. It also contains a few drops of mercury - which forms a tiny amount of mercury vapour. Mercury atoms account for about one thousandth of all gas atoms.
Fluorescent tubes rely on the mercury atoms of the lamp, which emit ultraviolet light (main wavelength 2537Å = 2537 x 10-10m) by the process of gas discharge. About 60% of the electrical energy consumed can be converted into UV light. The rest of the energy is converted into heat.
Fluorescent lamps emit visible light by absorbing UV light from a fluorescent substance on the inner surface of the lamp. Different fluorescent substances emit different types of visible light. In general, the efficiency of converting UV light into visible light is about 40%. The efficiency of a fluorescent lamp is therefore approximately 60% x 40% = 24% - approximately twice the efficiency of a tungsten lamp of the same power.
Energy saving lamps
Energy saving lamps, also called compact fluorescent lamps (CFL lamps for short abroad) have the advantages of high luminous efficiency (5 times that of ordinary light bulbs), significant energy saving, long life (8 times that of ordinary light bulbs), small size and ease of use. Its working principle is basically the same as that of fluorescent lamps.
In addition to the white (cold light) ones, energy saving lamps are now also available in *** (warm light). Generally speaking under the same wattage, an energy saving lamp is 80% more energy efficient than an incandescent lamp, lasts on average 8 times longer and radiates only 20% more heat. In non-strict terms, a 5 watt CFL light can be considered equal to a 25 watt incandescent, a 7 watt CFL light is approximately equal to a 40 watt and a 9 watt is approximately equal to a 60 watt.
LED Lamps
LED lamps (Light Emitting Diode), also known as light emitting diodes, are a solid state semiconductor device that converts electricity directly into light. The semiconductor wafer consists of three parts, one is a P-type semiconductor in which holes dominate, the other end is an N-type semiconductor in which electrons dominate, and in between is usually a quantum well of one to five periods. When current is applied to this wafer through a wire, electrons and holes are pushed into the quantum well, where the electrons compound with the holes and then energy is emitted in the form of photons, which is the principle of LED light emission.
