Why Scan When The Controller Input Part Of The Control Power, Scan To The Second Set Of First LED When The LED Cannot Be Completely Destroyed?

Scanner controller has been disconnected from the power supply input voltage, but due to the inside of the power supply electrolytic capacitors have a discharge process, it will keep the whole power continues to work and for a period of time, the power LED lights of the group will delay for some time to completely destroy, so after a second set of LED light, LED the first group are not destroyed.

In LED projects, scans the controller output power must be controlled with individual LED lights the input line is the middle of the group, this power does not affect LED the top group. Process of scanning all lights set to synchronization.