Switching power supply is a device that converts the direct current energy in the mains into high-frequency, high-voltage alternating current energy, which is composed of a switch tube and several rectifiers. So do you know what is the reason for the voltage drop when the switching power supply load is disconnected? Next, Mingjinfang will give you a detailed introduction to this problem.
Reasons for the voltage drop when the switching power supply load is disconnected:
The switching power supply generally has an output voltage for feedback, and the duty cycle of the switching power supply is adjusted according to the size of the voltage, and its working process is as follows
When the output voltage is detected to be small, the duty cycle becomes larger, the energy transmitted from the primary side of the switching transformer to the secondary side becomes more, and the output voltage increases.
When the output voltage is detected to be large, the duty cycle becomes smaller, the energy transmitted from the primary side to the secondary side of the switching transformer becomes more, and the output voltage decreases.
When the switching power supply is working, the above two processes are carried out alternately, so that the output voltage is stabilized at a certain value.
Suppose the switching power supply has two outputs, one output is 15V and the other output is 12V. 15V for feedback, and both voltages have a certain load, due to 15V for feedback, the voltage accuracy of this channel is higher, and the voltage change range is smaller when the load changes. If the coupling of these two windings is not very good, when the 15V load is disconnected, it is equivalent to the output power of the switching power supply is reduced, and the duty cycle is reduced, but because the 12V load is not reduced, the 12V voltage will be reduced. But how much it will be reduced, I think it has to do with the design of the transformer.
The above reasons for the disconnection voltage drop of switching power supply load are shared here for you, I hope this article will be helpful to you. If you have other questions about switching power supply, you can pay attention to Mingjinfang or leave a message, we look forward to working with you!