LED electronic display is a kind of current control device, LED driver is actually the driving power of LED, that is, the circuit device that converts AC power into constant current or constant voltage DC power. Unlike ordinary incandescent bulbs, LED electronic displays can be directly connected to 220V AC mains. LEDs have almost harsh requirements for driving power, and their working voltage is generally 2~3V DC voltage, and a complicated conversion circuit must be designed. LED lights for different purposes should be equipped with different power adapters.
LED devices have very high requirements for the conversion efficiency, effective power, constant current accuracy, power life, and electromagnetic compatibility of the LED drive power. A good drive power must take these factors into consideration, because the drive power is in the entire LED lamp. The role is as important as the human heart. The main task of the LED driver is to convert the AC voltage into a constant current DC power supply, and at the same time complete the matching with the LED voltage and current. Another task of the LED driver is to make the load current of the LED controlled at a pre-designed level under the influence of various factors.
There are conditions for the LED electronic display to emit light. The forward voltage is applied to both ends of the PN junction, so that the PN junction itself forms an energy level (actually a series of energy levels), and electrons jump at this energy level and generate photons to emit light. Therefore, the voltage applied across the PN junction is required to drive the LED to emit light. Furthermore, because LEDs are characteristic-sensitive semiconductor devices with negative temperature characteristics, they need to be stabilized and protected during the application process, thus giving rise to the concept of LED “drive”.
Anyone who has been in touch with LEDs knows that the forward volt-ampere characteristics of LEDs are very steep (the forward dynamic voltage is very small), and it is more difficult to supply power to the LED. It cannot be directly powered by a voltage source like ordinary incandescent lamps. Otherwise, the voltage With a slight increase in fluctuation, the current will increase to the point that the LED will be burned out. In order to stabilize the working current of the LED and ensure that the LED can work normally and reliably, various LED drive circuits have emerged.