Polymerbasierende Rückstellbare Sicherungen

Resettable fuses or PPTCs (Polymeric Positive Temperature Coefficient) are known under the trade names PolySwitch®, Multifuse®, Polyfuse® or Everfuse®. They protect the electronics connected in series in the event of a fault or against overcurrent by rapidly increasing the internal resistance. The fault current flow is limited by this increased internal resistance.

This is made possible by a conductive polymer, which changes due to the internal temperature increase (Pv=I²xR) caused by the higher current and ‘switches’ to the so-called tripped state. If the fault is rectified, the temperature of the polymer drops and the conductive carbon chains reconnect.

The device is ‘reset’ and the application is ready for use again.

Together with the manufacturer Polytronics, we offer resettable fuses under the trade name Everfuse® in SMD designs 0603 to 2920.

The fuses are available with holding currents from 40mA to 7.5A.

For portable or battery-operated devices, we offer a special series (SLR - Super Low Resistance) with particularly low internal resistance in housing types 0402 to 1210.

Their properties make polymer PTCs a cost-effective solution for short-circuit and overload protection.

All Everfuse® products are halogen-free and UL or TÜV certified. Automotive versions, tested according to AEC-Q200, are also available on request.

In addition to ISO 9001 and ISO 14001, Polytronics also has IATF 16949 automotive certification for its plants in Taiwan and China.

Samples are available and can be requested free of charge.