Now, with the energy conservation, the environmental protection of the word was on the agenda, people about life concept also a shift in recent years has LED to rapid industry requirements and keep pace with The Times. In the energy conservation, the environmental protection voice extremely high times, Indoor LED Display Screen further energy conservation and understandable become the industry support for the chase. The recent market appeared on the energy saving of the few of the Indoor LED Display Screen, those these energy-saving Indoor LED Display Screen will really energy saving? And how to design energy-saving Indoor LED Display Screen? ERALED from since its establishment has been concentrating on a full-color Indoor LED Display Screen research and development and production, at present energy-saving Indoor LED Display Screen have been put into market, let us to analyze the energy saving the display is how to design.
First of all, from the power supply power to see, if you would have a 5 V reduced to four V, rectifier schottky positive pressure drop in the output voltage of proportion will surely increase, switching power supply output voltage is lower, the forward voltage rectifying the schottky because of the high proportion of (the proportion X = V/V output pressure drop, output from the 5 V reduced to four V, join the pressure drop of 0.5 V, the proportion will rise from 0.1 to 0.125, 25%), the power supply output efficiency is low, the Indoor LED Display Screen screen for the overall energy-saving effect is not obvious, so use the power source design principle is obviously is unable to realize the power to promote the efficiency of work. At the same time, 5 V is nominal value of voltage, in use in the market has been quite mature, opening new switch power supply voltage, lower efficiency at the same time will only increase costs, quality is difficult to guarantee, realizing with difficulty.
Power design is a more mature areas, can use another design ideas of the display screen realization degree power supply, such as synchronous rectifier technology. Q10 for power MOSFET, in sub voltage of the positive half cycle, Q10 conduction, Q10 up rectifier role; In the secondary voltage negative half cycle, Q10 shut off, synchronous rectifier circuit power loss of mainly includes Q10 conduction loss and gate drive loss. When switching frequency less than 60 KHz, conduction loss dominant; Switching frequency more than 60 KHz, gate drive loss to give priority to. Low voltage, large in the design of the output current AC/DC or DC/DC converter, the synchronous rectifier technology can significantly raise the efficiency, even as high as 95%. The drive higher power of synchronous rectifier, grid peak demand drive current IG (PK) quartile 1 A, still can use CMOS high-speed power MOSFET drive. Of course this technology to the Indoor LED Display Screen power supply is the voltage drop can be to the necessary voltage value, at the same time, the efficiency of the power supply can achieve the general switching power supply voltage values, so use synchronous rectifier technology in to the Indoor LED Display Screen power supply is can achieve significant the effect of energy saving, power cost is sure to have some increase.
Second, we can carefully study the Indoor LED Display Screen screen drive IC, control output port of open or closed, output port pressure drop is VDS = 0.65 V or so, this is decided by technology and material, reduced to 0.2 V VDS, even 0.1 V, the area will increase itself. In the structure of the MOS tube can see, in GS, between GD parasitic capacitance, and MOS tube drivers, is actually the charging and discharging of capacitance. The charging and discharging process is need period of time, the area if increase in MOS pipe parasitic capacitance will also will also increase, so, as a consequence, it is the whole IC port response speed down, this to a Indoor LED Display Screen screen drive IC will be fatal weakness, so, want from IC starting, the turning point voltage reduction, and make the drive IC have enough response speed, the decisive role is the process, this is difficult to achieve. Some people think that can use any other design principle, but if is constant current IC, internal circuit is to be different, but the channel port of switch tube is must exist, so even if the other design principle, to achieve the purpose of voltage drop can be difficult to achieve.
To sum up, the realization of energy saving the Indoor LED Display Screen mainly from the power supply on begin, the drive IC constant current state of the power supply voltage reduce as far as possible, through the red, green, blue each tube core to separate the power supply of energy saving effect, of course, the cost of power supply will be increased. From the driver
IC is very difficult to achieve starting, that LED Display Screen the realization of energy saving and drive IC no connection, and it is only the power supply improvement. If the power used for ordinary driver IC, also can realize the effect of energy saving.
