Abstract: A fail-safe device is provided for use with a thyristor having a main body sandwiched between electrically conductive end plates. The fail-safe device includes a spring body formed of electrically conductive material having contact surfaces bent about a central fold. The thyristor is placed between the contact surfaces with the end plates in electrical opposition to each contact surface. A conductor plate is disposed between one of the end plates and one of the contact surfaces. The conductor plate includes a lead for electrical connection to the circuit to be protected. The spring body includes a lead for electrical connection to an electrical ground. A dielectric spacer is disposed between the conductor plate and the contact surface. The dielectric spacer is selected to deform in response to an elevated temperature generated by the thyristor during an over-voltage condition.

Abstract: An overvoltage protector for use with data cables. The protector is connected between the data cable and the piece of equipment to which the data cable is ordinarily connected. The equipment has a chassis ground. The protector includes first and second connectors for connection to the equipment and data cable, respectively as well as a protection circuit and a ground plane. The protection circuit is connected between the data cable connector, the equipment connector and the ground plane. The ground plane is in electrical connection with the conductive shell of the equipment connector. The protector is designed such that the ground plane is brought into electrical connection with the chassis ground when the protector is connected between the data cable and the equipment.

Abstract: A gas discharge arrester in which annular bands are attached to the inside surface of the arrester. The spacing between the bands is equal to or somewhat greater than the width of the interelectrode gap. Each band is in contact with its associated electrode. The bands function to minimize the effect that placing the arrester in a metallic cup has on the symmetry of the electric field in the arrester, and, at the same time, act to lower the impulse breakdown of the arrester.