PTC (positive temperature coefficient) fuses are safety devices used to protect electrical circuits from overheating or short circuits. PTC fuses, which have the feature of automatically cutting the electric current in case of exceeding a certain temperature, prevent damage to the electric circuit and reduce the risk of fire.

PTC fuses are widely used in various electrical and electronic devices such as power supplies, chargers and electronic devices. It is generally made of a conductive polymer material that becomes more resistant as its temperature rises, and has the ability to automatically cut off the electric current if a certain temperature is exceeded.

PTC fuses are often used in conjunction with other protective devices such as circuit breakers and thermal breakers and provide a multi-layered protection to electrical circuits. They are preferred over other types of fuses because they are relatively small and light and do not require the use of a separate fuse.

In general, PTC fuses are an essential component of electrical and electronic systems and are used to protect the safety of these systems and damage caused by overheating or short circuits.