PolySwitch™ resettable devices are the world’s leading PPTC (Polymeric Positive Temperature Coefficient) devices for circuit protection. PolySwitch devices are commonly called resettable devices to distinguish them from traditional single use fuses that work only once and then must be replaced. While the generic term – resettable fuses – is sometimes used for these devices, technically they are not fuses. They are non-linear thermistors that allow a circuit to return to normal operation after a fault has been cleared and power to the circuit has been removed. Used to help protect against damage from harmful overcurrent surges and overtemperature faults in electronic equipment, they help reduce the need for product service and repair. This means improved customer satisfaction and reduced warranty costs.