In daily contact with electronic products, we can find magnetic core components, including the heart of switch power supply - switch transformer. Nowadays, many electronic products are switch mode power supplies, so as practitioners in the electronics industry, they have to have some understanding of the transformers of switch mode power supplies. So what should I do if the temperature of the switch power transformer is too high?
Treatment method for high temperature of switching power transformer:
Step 1
Firstly, from the perspective of the transformer itself, once there is a high temperature rise, overheating, and heating situation, it is mainly caused by four problems.
1. They are: copper loss, winding process issues, transformer iron loss, and transformer planned power too low.
2. No-load heating refers to the insulation of the transformer being damaged or the input voltage of the transformer being high. If the insulation is damaged, the coil needs to be rewound. If the input voltage is high, the input voltage needs to be reduced or the number of coils needs to be increased.
3. If the voltage is normal and generates heat and heat under load, it means that the load of the power transformer is too large and the load design needs to be changed.
Step 2
In the design process of switching power transformers, the heating situation of MOS tubes is severe, and the problem of excessive temperature rise is caused by losses.
1. The loss of MOS transistors consists of two parts: the loss during the switching process and the on state loss.
2. Reducing on state loss can be achieved by selecting a switch transistor with low on state resistance. The switching process loss is caused by the size of the gate charge and the switching time. To reduce the loss during the switching process, devices with faster switching speed and shorter recovery time can be selected to reduce it.
3. But more importantly, designing better control methods and buffering to reduce losses, such as adopting soft switches, can greatly reduce such losses.
There is also a possibility that the temperature rise of the power transformer itself may be too high, which is the aging phenomenon of the transformer itself. When the engineer checks the transformer itself and the MOS transistor and finds no abnormalities, it is necessary to infer based on the working time and lifespan of the transformer.