There is a nonlinearity and variability between the out […]
There is a nonlinearity and variability between the output voltage and the current of the solar cell. There is a maximum power output point and a voltage-sum current corresponding to the maximum power point in a specific environment. When the environment changes, the output characteristics of solar cells also change. The characteristic curve of the output voltage and the output current of the solar cell of the LED equipment manufacturer is shown in Fig. 2. In order to obtain as much electric energy as possible from the solar cell, the maximum power tailing of the solar cell is raised. The most common methods for power point tailing control include constant voltage drive, constant voltage drive, constant voltage drive, perturbation observation method, conductance increment method, fuzzy logic control method, and load current/voltage maximum method. . According to the LED's volt-ampere characteristics, in the LE D's positive conduction zone, a small voltage swing will cause large changes in the current, so the choice of constant-current drive is the election plan.
LED fixture manufacturer's LED lighting artistic expression
The principle of LED lighting. The LED is made of a III-V compound such as GaAs (GaAs), GaAsP (AlGaAs), AlGaAs (aluminum gallium arsenide) and the like, and its center is a PN junction, so it has a general PN junction. Volt-ampere characteristics, that is, positive conduction, reverse cut-off, breakdown characteristics. When the P-type semiconductor is in contact with the N-type semiconductor, the carrier concentration is poor at the interface. Therefore, electrons and holes are dispersed from the high-concentration region to the low-concentration region. In this way, one side of the P region loses negative ions whose remaining voids cannot move, and the N region loses electrons, leaving behind unmovable positive ions. These non-movable charged particles are space charges. The space charge gathers near the interface between the P region and the N region, forming a very thin space charge region, that is, a P-N junction. When giving P-N junction a forward voltage. This changes the dynamic balance of the P-N junction.
When a small amount of carriers (a few sons) written are combined with a majority of carriers (multiple sons), the remaining energy is released as light, thereby converting the electric energy directly into light energy. If a reverse voltage is applied to the PN junction, a small amount of carriers (children) are difficult to write, and therefore do not emit light.
LED equipment manufacturer's white LED main method of completion. At present, GaN-based LED to obtain white light mainly include: blue LED + yellow phosphor, three-color LED constitutes white light, violet LED + three-color phosphor three methods. The most common way to build white light is the combination of blue LED chips and phosphors that can be effectively stimulated by blue light to form white LEDs. The LED emits blue light with a peak at 470 nm, while some blue light-emitting phosphors have a peak at 570 nm. Amber light. Blue light transmitted from the other part is mixed with yellow-green light that excites the phosphor to generate Y l O :Ce white light. Currently, most of the phosphors used are rare earth activated aluminates Y l O :Ce (YAG), which are called yellow-green phosphors when blue light excites it. The method emits light, high luminous power, simple preparation, and sophisticated skills. But the color changes with the angle. The optical consistency is poor, and the lifetime of the phosphor and the LED is also inconsistent. With the passage of time, the color rendering index and the color temperature will change, affecting the luminous quality of the light source. Select white, red, green and blue LED chips or three primary LED tubes. The former is a three-chip type, and the latter is a three-tube assembled type. The red, green, and blue LEDs are packaged in a single tube with a luminous efficacy of up to 20 lm/W, high luminous power, and good color rendering [31. However, the disadvantage of the white light approach is the LED driver circuit. More complicated. The cost of the three-chip three-primary color mixing is relatively high, and because the light decay characteristics of the three kinds of red, green, and blue LEDs are inconsistent, the three-color mixing ratio of the LED device manufacturer will be changed along with the addition of the use time. The color rendering index will also change the UV or violet LED to stimulate the three primary phosphors and generate white light. This method is more simple to obtain uniform white light, because the color is only determined by the ratio of the phosphor, in addition, can also achieve a high color rendering index. But its biggest difficulty lies in how to obtain high-power three-color phosphors, especially high-efficiency red phosphors. It is also important to avoid UV leaks.