Regarding the use of common mode inductors in switching power supplies, it has been asked more in recent days, and one of the more popular problems is that the common mode inductors of switching power supplies are burned out in use. If it is burned out in use, it is necessary to pay attention to the observation that it is an occasional case, not an incidental case. If the defective rate of burnout is relatively large, it may be more serious, and we can analyze and find the cause from the following aspects:
1. Whether the input voltage is unstable: If the input voltage exceeds the rated voltage range of the inductor, it will easily cause the inductor to burn out. Of course, too low an input voltage can also cause such a fault;
2. Check whether the circuit is burned due to overload or short circuit: whether the circuit is overloaded or short-circuited, a large current will be generated, and the sudden increase in current will lead to overheating of the inductor, causing a burnout fault;
3. Check whether it is burned out due to environmental factors: the influence of the inductor application environment on the use is a factor that is easy to ignore
4. It may be the burning caused by the quality problem of the inductor: the quality problem contains many factors, which may be the problem of the production material, or the problem of the manufacturing process, which will have an impact on the use of the inductor
5. It may be a circuit design problem: if it can be ruled out whether it is caused by an inductance problem, it may be a circuit board design defect, or a fault caused by other electronic components.
The above is the analysis of the possible causes of the heating and burning of the common mode inductor of the switching power supply, in addition to the above aspects, what do you think may be the cause?