Littlefuse Ireland Development Company Limited

Littelfuse Ireland Limited

Michael O'Donovan

Neil McLoughlin

John Matthew Kennedy

John R Foster

Nathan Siegwald

Brian Walaszczyk

Thomas Novak

Neil Mcloughlin

An integrated fuse device () includes a varistor stack (), a thermal fuse (), and a current fuse () within an enclosure () having device terminals (). The varistor stack () is connected to the thermal fuse () by a Cu terminal () and is connected to the device terminal () by steel terminal () of smaller cross-sectional area. Being of Cu material and having a greater cross-sectional area, the terminal () connected to the thermal fuse () has greater thermal conductivity than the steel terminal () to the end cap (). The thermal fuse () comprises a plurality of links having a melting point to melt with sustained overvoltage, the links having a diameter in the range of about 2 mm to about 3 mm. The links pass through an elastomer plug (), which exerts physical pressure on them to assist with opening during sustained overvoltage. Hot melt () around solder () of the thermal fuse limits heat conduction to back-fill sand.

Transient voltage surge suppression device

A varistor has a thermal fuse between a lead and an electrode. The fuse includes a link extending between the surface of an insulator and the fused electrode. The electrical connection of the link and the electrode is maintained by a low temperature solder fillet. That part of the link between the electrode and the insulator is surrounded by hot melt electrically insulating material. Upon sustained over-voltage conditions, the link and the solder fillet melt, and an insulating gap is rapidly created by molten hot melt material.

Thermally protected metal oxide varistor

Growing community of inventors

Dundalk, Ireland

Michael O'Donovan