The wavelength of ordinary UV lamp is 365 mm, which belongs to UVA, also known as aging radiation. Long-term exposure to UVA can cause skin damage and eye damage, and the damage can be cumulative and irreversible.
Many women may have noticed that more phototherapy can make their hands black and dry! And the LED lamp is visible light, the real source of science and technology - cloud express Wanciba screen, like ordinary lighting, no harm to human skin and eyes.
Because the wavelength of the LED lamp is longer than that of the UV lamp, it takes about 30 seconds to dry a nail glue LED lamp, while the ordinary UV lamp takes about 3 minutes to dry. In terms of curing speed, LED lamp is 4-6 times faster than UV lamp.
Usual UV lamp tube produces very high heat when it emits light. Usually the temperature is 50 - 70 degrees. It is easy to burn if it is touched carelessly.
And the LED is a cold light source, will not have the burning feeling of the UV lamp, even touch the lamp tube with your hand will not feel hot. At present, the market price of UV and LED light is quite different, and the price of LED light is higher.
Solar AC power generation system is composed of solar panels, charging controllers, inverters and batteries, while solar DC power generation system does not include inverters.
In order to make the solar power generation system provide enough power for the load, it is necessary to select the components reasonably according to the power of the electrical appliances.
The following is an example of using 100W output power for 6 hours a day to introduce the calculation method:
1. Firstly, the watt-hour consumed per day (including the loss of the inverters) should be calculated. If the conversion efficiency of the inverters is 90%, then when the output power is 100W, the actual output power required should be 100W/90%=111W; if the power consumption is 111W*5 hours=555Wh if the inverters are used for 5 hours per day.
2. Calculate solar panels: According to the effective sunshine time of 6 hours per day, considering the charging efficiency and the loss during charging, the output power of solar panels should be 555Wh/6h/70%=130W. Among them, 70% is the actual use power of solar panels in the charging process.
Solar energy lamp, can be widely used in lawn, square, Park and other occasions of decoration, belongs to the technical field of lamps and lanterns. The lampshade is mainly used to connect the bottom bracket, the battery board is placed on the battery box and placed in the lampshade, the battery box is installed on the bottom bracket, the light emitting diode is installed on the battery board, and the solar panel is connected with the rechargeable battery and the control circuit by a wire.
The utility model has the advantages of integration, simplicity, compactness and reasonableness; no external power cord, convenient use and installation, beautiful appearance; because the light emitting diode is placed in the base, the whole lamp body is illuminated after illumination, and the photosensitivity effect is better; all electrical components are built-in, which has good practicability. Including snake lamp, plate lamp, solar neon lamp, massage lamp and so on.
In practice, of course, solar outdoor lighting is a little more complicated. In addition to large-capacity batteries and solar panels, the system also includes advanced dedicated monitors, and when lighting stops, solar-powered batteries start charging, and then recharge, they get more power.
This is the key to solar outdoor lighting, solar photovoltaic houses with solar panels, there is a dedicated microprocessor control system and batteries.
It is connected to a specially designed load lamp with a hyperreflectivity and high energy ballast. The utility model has the advantages of high brightness, simple installation, reliable operation, no laying of cables, no consumption of conventional energy, long service life, etc. High brightness LED light emitting diode design, no manual operation, automatic lighting in dark, automatic extinguishing in daylight.
At present, crystalline silicon materials (including polycrystalline silicon and monocrystalline silicon) are the main photovoltaic materials. Their market share is more than 90%, and they will remain the mainstream materials of solar cells for a long time to come.
The production technology of polycrystalline silicon materials has long been in the hands of 10 factories of seven companies in three countries, namely, the United States, Japan and Germany, forming a situation of technological blockade and market monopoly.
The demand for polycrystalline silicon comes mainly from semiconductors and solar cells. According to purity requirements, it can be divided into electronic level and solar level. Among them, about 55% are used in electronic grade polysilicon and 45% are solar grade polysilicon.
With the rapid development of photovoltaic industry, the demand of solar cells for polycrystalline silicon is growing faster than that of semiconductor polycrystalline silicon. It is expected that the demand of solar polycrystalline silicon will exceed that of electronic polycrystalline silicon by 2008.
In 1994, the total output of solar cells in the world was only 69MW, whereas in 2004 it was close to 1200MW, increasing 17 times in just 10 years. Experts predict that solar photovoltaic industry will surpass nuclear power as one of the most important basic energy sources in the first half of the 21st century.
For general lighting, white LED is usually formed by two methods in the process structure. The first is to use "blue light technology" to form white light with phosphor; the second is to use a variety of monochrome light mixing methods.
Both methods have successfully produced white light devices:
The first method of generating white light is shown in Figure 1. The LED GaM chip in the figure emits blue light (lambda P = 465 nm), which is packaged with YAG (yttrium aluminium garnet) phosphor. When the phosphor is stimulated by blue light, it emits yellow light. As a result, blue light and yellow light mix to form white light (the structure of the LED is shown in Figure 2).
In the second method, chips with different colors are packaged together, and white light is produced by mixing different colors.
In order to illustrate the characteristics of white LED, first look at the lighting source used. The light efficiency of incandescent lamp and halogen tungsten lamp is 12-24 lumens/watt, and that of fluorescent lamp and HID lamp is 50-120 lumens/watt.
White LED: In 1998, white LED had a light efficiency of only 5 lumens/watt, up to 19.