A terminal block for interconnecting conductors in telecommunications circuits is disclosed. The terminal block allows a plurality of telecommunication wires to be progressively connected to a connector member. The terminal block includes a conductor transporting driver module having passageways that customer wires and service wires are inserted into and a connector chamber housing two insulation displacing connector members for the tip and ring lines. Wires are connected to the connector member progressively through a cyclical motion of the driver module relative to the connector members along a path of travel having an angle relative to a mounting surface which facilitates easy access to both wires and a threaded fastener actuating the driver module even in the most demanding telecommunications housing environments.

Telecommunications terminal block

A cold-cathode, plasma discharge modulator switch (Fig. 2). A corssed-field discharge plasma (30) supplies charge carriers for the switch. A dc magnetic field (25) is employed to provide a highly localized cusp magnetic field near the cathode (7), so that plasma ionization occurs primarily in the cathode-source grid gap. The region between the cathode (7) and anode (1) is filled with a relatively low pressure gas. A highly transparent control grid (8) with small apertures is closely spaced from the anode (1). The switch is closed through application of positive potential (relative to the plasma) to the control grid (8), and opened through application of negative potential relative to the plasma to the control grid (8). The application of negative potential to the control grid (8) creates an ion sheath around the control grid (8) which permits plasma cut-off to the anode region provided the sheath size is larger than the control grid aperture radius. Upon plasma cut-off, the switch current is interrupted as the remaining plasma in the control grid-anode gap decays. Low pressure operation insures that ionization cannot sustain the plasma in the narrow, isolated control grid-anode gap.

Modulator switch with low voltage control

An electrical device in which a first resistive element which is composed of a first electrically non-linear composition is in electrical contact, and preferably in physical and electrical contact, with a second resistive element which is composed of a second composition which has a resistivity of less than 100 ohm-cm. The first composition has a resistivity of more than 10 9 ohm-cm and contains a first particulate filler. The second composition contains a second particulate filler which (a) is magnetic and electrically conductive, and (b) is aligned in discrete regions in the second polymeric component. The device also contains first and second electrodes which are positioned so that current can flow between the electrodes through the first and second resistive elements. Devices of the invention have relatively low breakdown voltages and can survive high energy fault conditions.

Laminar non-linear device with magnetically aligned particles

A surge suppressing device includes a voltage-dependent resistor having an opening formed therethrough. A pair of preformed pads formed of an electrically conductive material is located adjacent a first and second side respectively of the voltage-dependent resistor proximate the opening. The electrically conductive material flows through the opening creating an electrical short between the first and second sides when the voltage-dependent resistor is heated in response to excessive leakage current flowing therethrough.

Surge suppressing device

Disclosed herein are surge arrester configurations employing non-metallic and preferably plastic fusible elements which normally insulate biased short circuiting members from shorting the surge arrester but which, in the event of certain forms of excessive overloads, fuse to thereby permit the shorting elements to short circuit the arrester gap. In addition, the embodiments include integral backup air gaps to provide additional backup protection covering certain gas tube failure modes. In the illustrated embodiments, the shorting elements each take the form of a conductive clip with one set of spring fingers in electrical contact with the line (end) electrode and another set urged in the direction of the ground electrode but separated therefrom by an annular plastic fusible sleeve coaxially coupled to the center body housing. Fusion of the sleeve in the presence of a sustained overload causes it to yield, thereby permitting the respective spring fingers to move into contact with the ground electrode, causing a short circuit.

Fail-safe/surge arrester systems

In an excess voltage arrester comprising a pair of spaced electrodes housed in a gas-filled enclosure the electrodes extending towards one another from end caps through respective tubular insulating portions of the enclosure so that the gap between the electrodes lies within a central conductive tubular portion of the enclosure, the radial dimensions of the electrodes and the tubular portions of the enclosure are chosen so that the d.c. ignition voltage of the arrester is lower than the breakdown voltage between the electrodes and sputtered coatings which may form on the internal surfaces of the insulating portions of the enclosure.

Excess voltage arresters

A heat-operated short-circuiting arrangement comprising an enclosure formed at least partly of a heat-shrinkable material; a pair of terminals for external connection of the arrangement which provide spaced surfaces within the enclosure; and at least one element of a fusible, electrically conductive material housed within the enclosure; the arrangement being such that the fusible element or elements melt on heating of the arrangement and the resultant molten material is caused to flow due to shrinking of the heat shrinkable material to a position where the molten material establishes electrical connection between said spaced surfaces of the terminals. The arrangement finds application in combination with an electrical device for short-circuiting a pair of terminals of the device in the event of overheating of the device.

Heat-operated short-circuiting arrangements

An electric circuit interrupting device comprising a gas-filled envelope containing an anode and a cathode, and between them a screen with an aperture through which a discharge can pass between anode and cathode. Means are provided for producing a magnetic field adjacent the aperture, and directed parallel to the path of the discharge, the maximum transverse dimension of the aperture being sufficiently small so that, when a discharge is passing, the presence of the magnetic field causes the discharge to be quenched.

Basil Offor Baker

Papers

Excess voltage arresters

Heat-operated short-circuiting arrangements

Gas-discharge device with magnetic means for extinguishing the discharge