Surface mount fuses are one of the new varieties with high technical content in the small fuse industry. It includes surface mount current fuses and surface mount self-recovery fuses. When selecting them, the following five techniques need to be considered:

1. Determine the normal current. The normal current is the fuse that flows through the circuit chip and must be less than the rated current and the product's derating factor.

2. Consider the melting current. According to UL standards, surface mount fuses should be twice the rated current that works quickly. However, to ensure reliable fuses, it is recommended that the melting current should be greater than 2.5 times the rated current. In addition, the melting time is also essential, and judgment should be made based on the manufacturer's melting characteristics.

3. Consider the short-circuit current. The short-circuit current is the maximum current value when we call it a short circuit. The rated breaking capacity of various fuses is necessary, and do not choose a fuse circuit current exceeding the rated breaking capacity. Otherwise, it may cause the fuse to break or cause a fire.

4. Consider the impact current. Observe the influence of the current waveform (pulse current waveform) and calculate its energy with the I2t value (Joule integral value). The size and quantity of the effect produced by the current on the fuse are different. The impact is compared with the current value of the fuse's I2t and determines the number of fuse resistances for the time of a single pulse surge current.

5. Consider the open circuit voltage. The open circuit voltage should generally be selected as less than the rated voltage. For example, when the rated voltage is AC100VDC24V fuse circuit, it can ignite the fuse or cause the surface mount fuse to rupture.

These are the selection techniques for surface mount fuses. By paying attention to these five techniques, you can easily deal with fuse selection issues. I hope it will be helpful to everyone.