Eaton Corporation

Cutler-Hammer, Inc.

Roy Hyink

Herman P Schutten

Robert W Lade

Gordon B Spellman

Stanley V Jaskolski

John W Kroll

A shutter 4 is movably mounted in a housing 6 for actuation between given positions by an SME (shape memory effect) element 8 in response to a given level of current flow through the SME element 8 causing I.sup.2 R heating of the latter above its transition temperature. The shutter 4 may be an indicator flag exposed by a window 10 in the housing 6, or may interrupt an optic beam 22.

SME shutter mechanism

A semiconductor device is disclosed comprising a temperature sensitive thyristor thermally coupled to a power switching thyristor and electrically connected in parallel with the gate of the latter. The temperature sensitive thyristor senses the temperature of the power switching thyristor and automatically responds thereto above a predetermined temperature by shunting the gate current to prevent overheating of the power switching thyristor. The device may additionally include a second temperature sensitive thyristor having a lower switching temperature than the first mentioned thyristor and connected in series with the gate of the power switching thyristor whereby the latter may be triggered into conduction only within a defined temperature range bounded by the switching temperatures of the temperature sensitive thyristors. Normally off and normally on devices are also disclosed.

Thermally self-protected power switching semiconductor device

Growing community of inventors

Wauwatosa, WI, United States of America

Roy Hyink