Abstract A heavy duty PTC resistor with a pressed and sintered hollow cylindrical body of a ceramic composition which has two end faces in a radial plane with a connection contact on each end face. A heavy duty PTC resistor sintered body of a ceramic composition which has two end-faces carrying a connection contact; the invention also concerns a method of manufacturing such PTC-resistor. High duty PTC-resistors are required for some purposes. If for example a PTC-resistor is used as a starting device for a single-phase motor, it has to be designed to deal with almost the entire mains voltage and to carry power of 500 W or more. The usual cylindrical bodies, provided at their two end-faces with connection contacts, frequently exhibit cracks under loads of this kind. A high-duty PTC-resistor is thus known (German Patent Specification OS 1 465 349) which is made up of a stack of solid or hollow flat cylindrical discs, the end-faces of the superposed discs being interconncted by a contact layer.
A heavy duty PTC resistor comprising two pressed and sintered bodies of a ceramic composition, each of said bodies having two end faces each carrying a connection contact, said end faces extending parallel to the direction of the force with which the associated one of said bodies was loaded during pressing, said resistor having the form of two halves of a hollow cylinder, said end faces being in radial planes of said cylinder.
Claim 2
Dependent Claim
73 words
A heavy duty PTC resistor comprising two pressed and sintered bodies of a ceramic composition, each of said bodies having two end faces each carrying a connection contact, said end faces extending parallel to the direction of the force with which the associated one of said bodies was loaded during pressing, said resistor having the form of two halves of a hollow cylinder, said end faces being in radial planes of said cylinder.
Claim 3
Dependent Claim
26 words
A PTC resistor according to claim 1 wherein said two halves of said hollow cylinder are joined together with contact pieces interposed between said end faces.
Claim 4
Dependent Claim
24 words
A PTC resistor according to claim 2 wherein said contacts consist of metal pieces which extend externally of said bodies in an axial direction.