How to Design LED display screen to save energy?

Words such as energy conservation and environmental protection have appeared in society and even in the whole world. People have also changed their way of life and their concept of life. In the development of LED industry in recent years, energy conservation will also become the top priority of the LED industry. This is an era of energy saving and environmental protection. The further energy saving of LED display screen has become the supporting point pursued by this industry. There are a few energy-saving LED displays on the market recently. Will these energy-saving LED displays really save energy? So how to design energy-saving LED displays? Let's analyze how the energy-saving display screen is designed. First of all, from the point of view of power supply, if 5V is to be reduced to 4 V, then the proportion of forward voltage drop in the output voltage of xiaokeite can be increased, this also reduces the voltage output by the switch's power supply, because the higher the proportion of rectified Schottky forward voltage ( Its specific gravity X = V voltage drop/V output, the output drops from 5V to 4 V, and its voltage drop is 0. 5 V, its specific gravity will be from 0. 1 rose to 0. 125, increased by 25) The lower the power output efficiency, which is not too obvious in the overall energy saving of the LED screen. Therefore, it is obviously impossible to improve the working efficiency of the power supply by adopting this power supply design principle. At the same time, 5V is the nominal voltage, which is quite mature in market application. If the new power supply voltage is enabled, although the efficiency is reduced and the cost is increased, however, it is difficult to guarantee the quality, so it is difficult to achieve such practice. The design of power supply is a relatively mature field, and another design idea can be adopted to realize the power supply of degree display screen, such as synchronous rectification technology. Q10 is a power MOSFET. In the positive half of the secondary voltage, Q10 is turned on and Q10 plays a rectifying role. In the negative half cycle of the secondary voltage, Q10 is turned off, and the power loss of the synchronous rectification circuit mainly includes Q10 conduction loss and gate drive loss. When the switching frequency is lower than 60 KHz, conduction loss dominates; When the switching frequency is higher than 60 KHz, the Gate Drive loss is the main one. When designing AC/DC or DC/DC converters with low voltage and high current output, synchronous rectification technology can significantly improve power supply efficiency, even as high as 95. Secondly, we can carefully study the led screen driver IC to control whether the output port is turned off or on, and the output port voltage drop is VDS = 0. About 65 V, which is determined by technology and materials, VDS should be reduced to 0. 2 V, even 0. 1 V, the area required by itself will inevitably increase. In the structure of MOS tube, it can be seen that there is parasitic capacitance between GS and GD, while the driving of MOS tube is actually charging and discharging the capacitance. This charging and discharging process takes some time. If the area increases, the parasitic capacitance on the MOS tube will also increase. As a result, the response speed of the entire IC Port will decrease. this will be a fatal weakness for an LED screen driver IC. Therefore, it is difficult to realize that it is the process that wants to start from the IC, reduce the turning voltage, and at the same time make the driving IC have sufficient response speed. Some people think that other design principles can be adopted, but if it is a constant current IC, the internal circuit may be different, but the switch tube of the Channel port must exist, so even if other design principles are adopted, it is also difficult to achieve the purpose of voltage drop. From the above statement, it is not difficult to find that in fact, in the energy-saving collection of LED, the main thing is to start with the power supply, that is, in the constant current state of the driving IC, the input of the power supply voltage must be reduced, the red, green and blue tubes are powered separately, which can also achieve energy saving, but the cost will increase. It is really difficult to start with IC, that is to say, the realization of LED energy saving has nothing to do with IC at all, and it is only an innovation in power supply. We might as well make such an assumption that a power supply can be used on a common drive IC. In fact, it can also meet the effect requirements of energy saving.