RUEF400K, Resettable Fuses - PPTC 4A 30V 40A Imax

PolySwitch Resettable Devices Littelfuse PolySwitch and POLY-FUSE Devices are Polymeric Positive Temperature Coefficient (PPTC) devices that offer a resettable overcurrent protection alternative, reducing warranty, service, and repair costs. PTCs increase resistance as temperature increases due to increased flow. The components are designed to limit unsafe currents while allowing constant safe current levels, resistance will "reset" automatically when the fault is removed, and temperature returns to safe levels. The ability of the PTCs to reset themselves after exposure to a fault current makes them ideal within circuits that are not easily accessible. PTCs are typically used as circuit protection in applications where sensitive components are at constant risk of damage from overcurrent conditions. The components are also ideal for situations where frequent overcurrent conditions occur or constant uptime is required. Littelfuse Resettable PTCs (PPTCs) are typically used in consumer electronics, power line, telecom, I/O port, process control and medical equipment protection applications.