Abstract: A PTC heater for securely positioning resistors is disclosed. The PTC heater has two insulating plates having a plurality of square or rectangular through holes, a conductive position plate having a plurality of square or rectangular through holes facing toward those in the insulating plates and a resistor cavity defined by four angular-shaped fixing chips fixed on each of the four inside faces for positioning a PTC resistor therein, and a conductive elastic plate having a plurality of square or rectangular through holes facing toward those in the insulating plates. The elastic plate has an elastic projection on each of the four inside faces of a through hole for pressing a lateral surface of a PTC resistor positioned in a through hole of the position plate after the elastic plate and the position plate have been sandwiched between the two insulating plates.

Abstract: A pair of plates of good heat and electric conductivity have a plurality of openings and a plurality of foraminous areas. The plates are secured to one another with the openings and foraminous areas of the two plates aligned with one another. The plates are connected to terminals of opposite electrical polarity and are insulated from one another. A plurality of perforated PTC thermistor elements are clamped between the plates and in electrical contact therewith. Each element is aligned with openings in the plates. The openings and foraminous areas are so disposed that the openings associated with the elements are surrounded on at least two sides by foraminous areas.