Raychem Limited

Martin A Wright

David Crofts

A circuit protection device comprising a chalcogenide glass threshold switching element connected or arranged to be connected between a current carrying line and earth, and a capacitor connected in a series with the switching element.

Overvoltage protection device

An arrangement for protecting an electrical circuit from a voltage transient having a fast rise time, e.g. in the order of 20 Vns.sup.-1 comprises a number of semiconductive threshold foldback switching elements preferably formed from a chalcogenide glass, in parallel with one another between the current carrying line of the circuit and earth. An additional, non-linear, circuit protection device is connected in parallel with the switching element between the current carrying line and earth, in order to pass high frequency components of the transient to earth.

Circuit protection arrangement

An arrangement for protecting an electrical circuit from a voltage transient having a fast rise time, e.g. in the order of 20 Vns.sup.-1 comprises a number of semiconductive threshold foldback switching elements, preferably formed from a chalcogenide glass, in parallel with one another between a current carrying line of the circuit and earth. One or more capacitors are connected in series with the switching elements between the current carrying line and earth in order to prevent any direct currents in the current carrying line holding the switching elements in their low resistance state.

Growing community of inventors

Swindon, United Kingdom

Martin A Wright