PTC Resettable Fuse

Positive Temperature Coefficient (PTC) resettable fuses are
simple, cost-effective overcurrent protection devices. These
thermistor-based components protect circuits and downstream
components against too much current due to an overload or
short circuit fault condition. PTCs are compact, self-resetting
fuses that provide reliable circuit protection when replacing a
one-time fuse is either too costly, impractical, or impossible to
perform.