Design of a New Multi-output Constant Current Source Based on Power Allocation Control Strategy

In order to reduce the cross-regulation rate of multi-output constant current source and further improve the stability and accuracy of output current, a new design method based on power distribution control strategy is proposed. The system adopts the flyback converter as the main topology of the multi-output constant current source. The ARM system samples the real-time load value of the multi-output and combines the target current to determine the total power of the multi-output at this time. The total output power is the total input power. Ideally, combining the energy transfer of each output switch state of the multi-output flyback converter, the conduction time of the main switch transistor and the secondary side switch transistor of the flyback converter can be calculated, so as to distribute the power rationally on the transformer, thereby achieving reduced cross-regulation and improved current accuracy and stability. The experimental results show that a new multi-output constant current source system based on power distribution control has lower cross-regulation rate and the output current accuracy is within ±2% mA, which improves the accuracy and stability of the output current.