In our daily life, more and more LED products are used widely in public. If all LED is in tandem, the output voltage of power supply will be large. If all LED is in parallel, the output current of power supply will be large. No matter in tandem or parallel, we limit the quantity of LED and the cost of driver will be higher. We can adopt tandem and parallel together at the same time and the quantities of tandem and parallel are equal distribution. So each branch voltage, current, brightness of tandem LED is same.
We adopt constant voltage or constant current driving mode, the current of tandem circuit will be larger when a tandem branch of poor LED occurs short circuit, which is very easy to damage tandem branch of LED. Large current passes the poor LED, the circuits often occurs break. If we switch off a parallel branch, the output current of driver will be smaller with stable voltage driving mode, which cannot influence other LED working smoothly. If we adopt constant current LED driving mode, the output current of driver will keep constant, and the other LED current will be larger, however, that is very easy to damage all LED. How to solve it? We can do our best to adopt multi-parallel LED. When switching off a branch LED, the other LED current will not too large and not influence the other LED working.