PTC panel heater with small rush current characteristic and highly heat insulating region corresponding to heater location to prevent local overheating

摘要

PCT No. PCT/JP92/01069 Sec. 371 Date Apr. 8, 1993 Sec. 102(e) Date Apr. 8, 1993 PCT Filed Aug. 25, 1991 PCT Pub. No. WO93/04490 PCT Pub. Date Mar. 4, 1993A panel heater comprising, on an upper surface of a metallic sheet (2) provided with PTC ceramics (1) on the back side thereof, a highly insulating material or an open space (4) at the portion corresponding to the back side portion to which the PTC ceramics are provided, with a material (3) for conducting heat from the metallic sheet being thus provided to the rest of the surface side of said metallic sheet, and a finishing sheet (5) being established on the upper surface of the whole structure. More preferably, the metallic sheet (2) is provided with equally spaced concave grooves with PTC ceramics (1) on the back plane of said grooves and a highly insulating material or an open space (4) inside said grooves, and a finishing sheet (5) established thereon. Accordingly, a simply structured panel heater resistant to heavy loads yet free from local overheating is provided.