Patent ID: 6922131

Claim:
An electrical assembly comprising (A) first and second electrical devices, each of which devices comprises (1) a laminar PTC element which (a) comprises a conductive polymer composition which exhibits PTC behavior, (b) has first and second major surfaces, (c) has a thickness t mm which is at most 2.5 mm, and (d) has a perimeter p mm which is at most 50 mm; (2) a first metal foil electrode which is attached to the first surface of the PTC element; (3) a second metal foil electrode which is attached to the second surface of the PTC element; and (4) a first insulating layer which comprises an electrically insulating material which conforms to at least part of the perimeter of the PTC element; each of which devices (a) having an initial resistance at 20° C. of at most 6 ohms; (b) having a capacitance of at most 150 pF; and (c) meeting the requirements of UL1950 power contact test M-1, and (B) an additional insulating layer which surrounds the first and second devices, the first device, after being subjected to a 250 VAC/3 A test for a period of 15 minutes followed by a period of at least 1 hour during which no power is applied to the device, having a resistance which differs by at most 1.5 ohms from that the second device subjected to the same electrical test.