Asea Brown Boveri Ab

Abb Research Ltd.

Tomas Hansson

Per-Olof Karlstrom

Ola Jeppsson

Lars Banghammar

Maria Bijlenga

Device for current limitation and protection against short-circuit

A PTC element has at least one body and two electrodes. The body or bodies has/have and is/are two parallel surfaces, of an electrically conductive polymer composition with a positive temperature coefficient. At least one of the parallel surfaces on the body, or on one of the bodies, of polymer composition is in free contact with an electrode or with a parallel surface on another body of electrically conductive polymer composition. A pressure device exerts a pressure directed perpendicularly to the parallel surfaces on the body, or the bodies, on the electrodes. The pressure device is preferably provided with pressure-exerting devices with the ability to be resilient. After changing from a low resistance to a high resistance state, the PTC element returns to the initial resistance and is reusable after having been subjected to short-circuit currents. The parallel surfaces on the body, or the bodies, of polymer composition may be concentric.

PTC element

Device for motor and short-circuit protection

Growing community of inventors

Enkoping, Sweden

Tomas Hansson