Polymeric Positive Temperature Coefficient (PPTC) is an electronic fuse device that combines the functions of overtemperature protection with those of a relay.
A PPTC device is a temperature-dependent device with a low resistance that rises rapidly at a certain temperature rise and limits the current. In this function, the PPTC locks and remains in this state even when the temperature load drops. It is not reset until the supply voltage has been switched off and on again. Because of its function, the PPTC is also called a resettable fuse.
The PPTC serves equally as a thermal fuse and also as overcurrent protection. It is designed for different voltages and does not have to be replaced like a fuse in the event of damage.
PPTCs are used on transformers and motors, especially in industrial plants, household appliances, as circuit protection in automotive technology for electric window regulators or mirrors, and as overload protection in cable harnesses.