In order to achieve adjust color temperature, set conduction voltage drop of Cool white、 warm white led module with input voltage to the same . use power transistors(MOS1& MOS2) to control open and closed for the Cool white、warm white led module . The signal of PWM2 interfaced GATE of MOS1to control Cool white led array . The signal of PWM3 interfaced GATE of MOS2 to control warm white led array.

Operation process：

Each of the first and second switches alternatively performs a turn-on operation and a turn-off operation. First cool white led array is turn-on when PWM2 as high logic level and or PWM3 as low logic level . Then to do the opposite。 the warm white led array is turn-on and the cool white led array is turn-off. Use the duty-cycle of PWM to modulate the turn-on time of Cool white、 warm white led module . Linear LED dynamic display system based on linetype array, which is the effect of persistence of vision, is manufactured. So can implement the effects of change Of color temperature.