Analysis and Design of LED Constant Current Source Based on Current Mode Control

A drive module of LED constant current source with the output power of about 50W was designed,and the load is a LED array consisting of multiple hybrid LED tubes,and the power of each LED is 1W.By designing and manufacturing of the current-mode flyback converter and constant current control circuit,tests with different loads under different input voltages indicate that the current change laws are similar for each condition.As the load decreases,the output voltage increases but the output current decreases,the output current stability will be up to 4.6%.Under a certain load and the output voltage maintaining at around 47.2V,the voltage ripple peak-peak value will be approximately 400mV.The current fluctuation is about 0.05A, and the output current is stable and reliable,which can be used for power supply of multiple hybrid LED array.