PTCs as Resettable Current Fuses

Ceramic PTC thermistors are often used as re-settable current fuses as they offer several benefits over conventional fuses. Over-voltage or over-current conditions cause the PTC thermistor to “switch” from a low resistance to a high resistance state, effectively limiting (switching off) the through current. The PTC acts as a current fuse and protects the electronic circuit, electrical appliance or series load.
Often simpler to incorporate in a circuit than a current fuse, PTC fuses also don’t need replacing and thus help to minimise service calls when nuisance tripping is caused by various transient surges.


  • Applications requiring over-current and/or over-voltage protection


  • A range of 120ÂșC trip available
  • Max voltage: 270VDC
PTCs as Resettable Current Fuses Line Drawing