I do 12V2A switching power supply when the 2A load, under normal circumstances work is normal. But is the beginning of the load that moment, when adding more than 1.3A, the output voltage dropped first low and then quickly returned to normal, what reason?
This is of course not normal, the same load, for someone else's power but not the problem. How should we solve this problem? Just test a phenomenon is that when the sudden removal of the load when the voltage is also the first drop and then return to normal state. How to solve it?
this is normal phenomenon. The load becomes larger, to maintain the same voltage, the power output impedance will become smaller, power duty cycle to become larger, the adjustment is the time required, the dynamic response speed of the voltage drop will be relatively small.
Before the load, the current is not large, switch on and off time ratio is to meet the capacitor charge, discharge balance, to maintain the output voltage unchanged. When the load is connected, the load is mainly from the capacitor, the capacitor discharge quickly, the voltage drop is very low, the switch has not adjusted conduction and turn-off time than the capacitance of the charge and discharge balance, this adjustment is gradually It takes time. So the output voltage, that is, the voltage on the capacitor, the first rise after the rise.
To increase the dynamic dynamic response speed of the power supply, it is necessary to increase the power supply bandwidth. With external feedback can adjust the feedback power supply bandwidth (bandwidth is easy to instability, to ensure stable power), or increase the output capacitor can also increase the power supply bandwidth.
