Resettable Fuses - PPTC (Polymeric Positive Temperature Coefficient) are circuit protection components designed to limit excessive current by transitioning from a low-resistance state to a higher-resistance state when an overcurrent condition causes self-heating. Unlike single-use fuses, PPTC devices are intended to recover toward their original conductive state after the fault is removed and the device cools.

These components provide a reusable form of overcurrent protection and are commonly categorized within circuit protection for their ability to help reduce damage risk from abnormal current events while enabling automatic restoration of operation.

• Function: Overcurrent limiting through a temperature-dependent resistance increase
• Reset behavior: Returns toward normal operation after the fault condition clears
• Technology: Polymeric PTC material-based protection element