Abstract: A common mode signal attenuator includes a magnetic core, and a communications cable having at least one conductor adapted to transmit a communications signal. The communications cable is magnetically coupled to the core to form an inductive element having a magnetic flux path passing through the core. The inductive element has a volt-time capacity of at least about 0.0001 volt-seconds.An electrical transient suppression system includes an electronic device having a ground path, a communications cable, and a magnetic core. The communications cable has at least one conductor adapted to transmit a communications signal and is connected to the electronic device. The communications cable is magnetically coupled to the core to form a common mode signal attenuator having an inductance of about at least 10 times the inductance of the ground path.A method for reducing electrical transients in a communications cable includes magnetically coupling the communications cable to a magnetic core.

Abstract: A voltage regulator for regulating a power source that supplies an input signal includes input terminals connected across the power supply, a voltage sensor, a reference generator, a variable load unit, and a control unit. The voltage sensor is connected across the input terminals and receives the input signal and generates a scaled input signal from the input signal that is a fraction of the input signal in magnitude. The reference generator receives the scaled input signal from the voltage sensor and generates a reference signal. The variable load unit is connected across the input terminals. The control unit receives and compares the scaled input signal and the reference signal and instructs the variable load unit to dissipate a first portion of the input signal if the scaled input signal exceeds the reference signal.

Abstract: A transient voltage surge suppressor (100) for use in a single or poly-phase power distribution network to protect equipment supplied power from the network from damage caused by line surges or transients. A plurality of surge suppression assemblies (102A-102G) each of which includes a plurality of semiconductors (114) connected in parallel and a fuse wire (118) connected in series with each semiconductor. Each assembly is mounted on a separate circuit board (126A-126G). A fault detection circuit (104) in each assembly includes both a sensor (132A-132G) for sensing when a semiconductor in one of the surge suppression assemblies fails, or when a fuse wire in one of the assemblies clears, and a circuit (152) for providing a visual indication thereof. The fault detector is mounted on a separate circuit board (131).

Abstract: A transient voltage surge suppressor (10) is used in a single or poly-phase power distribution network (P). The surge suppressor connects in parallel between each phase (A, B, C) and neutral (N), each phase and electrical ground (G), and between neutral and ground. An improvement comprises an electrical circuit (30) for monitoring the loss of surge protection due to the occurrence of a current surge or voltage transient in a neutral-to-ground path (32). An MOV-type semiconductor (VR1) is connected in the ground-to-neutral path. The semiconductor is normally non-conducting, but switches into conduction when its voltage threshold is exceeded by a surge current or voltage transient. An excessive surge or transient causes the semiconductor to fail. Respective fuses (F1A, F2B) are connected in series with the semiconductor. These fuses clear (blow) upon a semiconductor failure to create an open circuit neutral-to-ground path.

Abstract: A coaxial cable (10) is for use in a power distribution network (N). The cable connects a surge protective device (SPD) in parallel with feeder lines (W1, W2) of the network. The SPD senses voltage surges on the feeder lines and clamps the voltages to a level at which loads (LD) connected downstream of the SPD are protected from excessive voltage levels. An inner conductor (12) and an outer conductor (14) have a dielectric material (16) separating them. The inner conductor is a round conductor, and the outer conductor forms a hollow cylinder in which the inner conductor and insulation material fit. A ratio of the inner diameter (D) of the outer conductor to the diameter (d) of the inner conductor is approximately 1.05. Thus, the diameter of the inner conductor is relatively large compared with the inner diameter of the outer conductor. A relatively large diameter of the inner conductor serves to minimize the dc resistance of the cable. Also, the dielectric material has a permittivity in the range of 2.0-4.0.