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In practical applications, excessive temperature rise often occurs in thepower transformer's MOS tube and the transformer design itself. Today, we will start from these two aspects to see how to effectively solve the problem of excessive temperature rise in switching power supply transformers.

First, from the transformer itself, once the temperature rises too high and becomes hot, it is mainly caused by four problems: copper loss, winding process issues, transformer iron loss, and insufficient transformer design power. No-load heating is due to transformer insulation failure or high input voltage. Insulation failure requires rewinding the coil, and high input voltage requires reducing the input voltage or increasing the number of coil turns. If the voltage is normal and the transformer heats up under load, it means the load of the power transformer is too large, and the load design needs to be changed.

In the design process of theswitching power supply transformer, the heating of the MOS tube is the most severe, and its excessive temperature rise is caused by losses. The losses of the MOS tube consist of switching losses and conduction losses. Reducing conduction losses can be achieved by selecting a switch tube with low on-resistance. Switching losses are caused by the gate charge size and switching time. Reducing switching losses can be achieved by selecting devices with faster switching speed and shorter recovery time. However, more importantly, losses can be reduced by designing better control methods and buffer technologies, such as using soft-switching technology, which can greatly reduce such losses.

In addition, another possibility that can cause excessive temperature rise in the power transformer itself is the aging of the transformer. When engineers check the transformer itself and theMOS tube and find no abnormalities, they need to make a comprehensive judgment based on the transformer's working time and service life.