What is constant pressure drive? Constant current refers to the current value specified at the time of constant output design within the allowable working environment of the drive IC; Constant voltage refers to the voltage value specified at the time of constant output design within the allowable working environment of the drive IC. LED display was always driven by constant voltage before. With the development of technology, constant voltage drive is gradually replaced by constant current drive. Direct flow solves the harm caused by the inconsistent current through the resistance when driving under constant pressure caused by the inconsistent internal resistance of each LED tube core. At present, LE display screen basically uses constant current drive. Constant current. It can also be divided into: 1. Static constant current drive. This scanning method is suitable for outdoor display screen, and its brightness is very high. The power constant current drive is divided into 1/2,1/8,1/16. Generally speaking, take 1/4 as an example. If the power supply provides current for one minute, it needs to scan four times in this minute. On average, one lamp is only on for 1/4 second. Dynamic constant current is applicable to indoor display, but 1/2 of them are used for semi outdoor display.