Abstract

A method of constructing a self-regulating electric heater particularly useful for heating compressor lubricant and the like is disclosed in which a cylindrical body of electrically insulative ceramic is formed with an axially extending generally parallelepiped shaped slot in communication with an end of the body. A positive temperature coefficient of resistivity (PTC) resistor, configured slightly smaller and complementary with the slot, is disposed therein. Axially extending grooves are formed in two opposed parallel walls of the body which, with two other cooperating walls, define the slot. The grooves are located on opposite sides of an axial plane perpendicular to the opposed walls. A platform is formed in each groove to serve as a stop surface to limit the insertion of spring biased terminals which are inserted in the grooves to provide electrical connection with the PTC resistor. The grooves are coextensive in length with the slot to permit reception of an injection nozzle to facilitate injection of thermal transfer material from the inside of the device to the outside to obviate trapping of air pockets. Finally, sealant material is disposed in the open end of the body with the terminal leads extending therethrough.