Circuit protection device having thermally coupled MOV overvoltage element and PPTC overcurrent element

摘要

In a composite electrical circuit protection device, thermal coupling between a planar PPTC element and a planar MOV element is controlled by insertion of a thermal mass material for regulating heat transfer from the MOV element to the PPTC element, such that a PPTC resistor hot zone forms consistently away from the planar major foil electrode confronting the MOV thereby regulating heat transfer from the MOV to the PPTC resistor.