A thermal fuse, also known as a fuse, is an electrical component installed on a circuit to ensure the safe operation of the circuit. Its function is that when the circuit fails or is abnormal, with the increase of current, the increase of current will damage the important parts and valuable parts of the circuit. There is also the possibility of burning the circuit and causing fire. When the fuse is set correctly in the transformer, when the temperature rises above the melting point of the fuse, the fuse blows out and automatically cuts off the power supply. And plays a role in protecting the safe operation of the circuit.

Transformer usually uses two kinds of temperature fuses, one is disposable and the other is recoverable. One-time temperature fuse is unrecoverable and cannot be connected repeatedly when it is protected or operated. The recoverable temperature fuse has the characteristics of recoverability. During protection or operation, the product can be repeatedly connected after it has cooled to a certain temperature.