Abstract: The invention is concerned with a bushing for high voltage applications and a bushing arrangement including such a bushing. The bushing includes a conductor defining a longitudinal axis (A) through the bushing where the bushing has a central section and a first and a second peripheral section on opposite sides of the central section along the longitudinal axis (A) and includes an optical fibre with a first part (P1) stretching through the central section, the fibre being adapted to detect physical properties being influenced or caused by the operation of the bushing. The sections are sections of a solid condenser core and the bushing further includes an enclosure for a length of fibre that is to exit the bushing, the enclosure being buried in the central section adjacent the surface of the condenser core and having an interior volume.

Abstract: A housing has electrically conductive top and bottom parts which together form an accommodation chamber. A circuit board is arranged in the accommodation chamber. A bottom side of the circuit board is connected electrically to the top side via conductive bores. The circuit board has circuit components and electromechanical plug components for connecting to components outside the housing. A first electrically conductive separating wall electrically connects the housing top part to the top side of the circuit board. A second electrically conductive separating wall electrically connects the housing bottom part to the bottom side of the circuit board. The first and second separating walls subdivide the accommodation chamber into first and second accommodation-chamber sections that are disposed on opposite sides of the first and second separating walls.

Abstract: A system and method for suppressing EMP-induced electrical system voltage surges due to detonation of a nuclear weapon, the EMP comprising E1, E2, and E3 component pulses. A plurality of shunting assemblies, each including MOVs, gas discharge tubes, other mechanical, electrical and ionization discharge devices and combinations thereof, detect and react to the overvoltage according to timing parameters associated with each of the E1, E2, and E3 components and shunt the overvoltage to decrease to under a predetermined allowable level. Respective shunting assemblies may include automatic self-monitoring of any faults in respective circuitry and also a challenge mode for on-demand circuit monitoring using an optical coupling switch, the optocoupler including an infrared light supplied by an LED flashlight and having a phototransistor light receiver.

Abstract: A sound producing apparatus is provided. The sound producing apparatus includes a sound producing device disposed at a sound producing location and configured to produce a plurality of air pulses according to a driving signal; a driving circuit, receiving an input audio signal and a channel-shaping signal and configured to generate the driving signal according to the input audio signal and the channel-shaping signal, wherein the channel-shaping signal is related to a channel impulse response of a channel between the sound producing location and a sound constructing location; a signal processing circuit, configured to generate the channel-shaping signal according to the channel impulse response.

Abstract: A control module for a motor vehicle having a base plate and electronic modules situated thereon is described. The electronic modules are encapsulated and the insulating compound which protects against environmental influences and is used for this purpose is a distance away from the edge of the base plate over the entire circumference.

Abstract: A heat dissipation device is provided in the present disclosure, where the heat dissipation device includes a hollow heat-sink base and a set of fluid tube. The fluid tube is inserted in the heat-sink base, and a cooling medium circulates in the fluid tube. The heat-sink base includes a heat absorption area configured to absorb heat. A cooling fluid, received in the heat-sink base, may be vaporized at the heat absorption area to absorb the heat taken by the heat absorption area, and condensed at a position that is inside the heat-sink base and away from the heat absorption area and on the fluid tube to release the absorbed heat.

Abstract: A phase-control switchgear includes a circuit breaker, a phase difference detection unit, a storage unit, and a circuit breaker control unit. The phase difference detection unit detects a phase difference between voltages of a specific phase (U-phase) of buses to which three-phase generators are respectively connected, at a plurality of time points. The storage unit stores the detected phase differences. When the three-phase generators are out of synchronization, the circuit breaker control unit estimates a breaking time point at which the phase difference between the voltages of the U-phase of the buses will be in the range of not less than ?80° and not more than 80°, based on the phase differences at the plurality of time points stored in the storage unit. The circuit breaker control unit opens the circuit breaker to break a current at the estimated breaking time point. This makes it possible to suppress a transient voltage generated between electrodes of the circuit breaker after the current is broken.

Abstract: In order to provide a method for regulating a reactive power compensator, which is connected to an alternating current line having multiple phases, wherein for each phase an actual voltage V12, V23 and V31 present thereon is detected and from the actual voltages V12, V23 and V31 a counter system actual fraction is calculated. A control circuit suppresses the counter system actual fraction. A feedback loop determines the level of suppression of the counter system actual fraction with the help of controlled parameters. The method enables an adjustment of the counter system that is largely independent from operating staff. Accordingly, a comparator unit compares the counter system actual fraction to the counter system target fraction and defines the controlled parameters as a function of the comparison.

Abstract: A bushing assembly including a first bushing element, a second bushing element, and a locking subsystem. The first bushing element has a first end, a second end, a first outer surface with a first outer diameter, a first inner surface defining a first channel, and a first flange positioned proximate the first. The second bushing element has a first end, a second end, a second inner surface having a second inner diameter greater than the first outer diameter, a second outer surface, and a second flange positioned proximate the second end. The second inner surface defines a second channel that receives a portion of the first bushing element. The locking subsystem is proximate the first end of the first bushing element and secures the first bushing element to the second bushing element.

Abstract: An apparatus for controlling a volume of an audio signal and method thereof are disclosed, by which a volume of an input signal can be controlled by using a non-linear gain curve and a target volume of the input signal. The present invention includes receiving an input signal and reference information controlling a volume of the input signal; and adjusting a volume of the input signal with the reference information, wherein the reference information comprises at least one of metadata indicating characteristics of the input signal, output environment information indicating characteristics of an environment in proximity to the apparatus and stored reference information being transmitted from memory. Therefore, the present invention is able to control a volume of an input signal adaptively by using reference information, for example metadata, outside environment information and stored reference information.

Abstract: The invention relates to distribution of electrical power, supervision and security. The invention comprises a power feeding station PFS for delivering electrical power. The PFS comprises a low voltage side LVS, a high voltage side HVS and a transformer TF which is configured to deliver high voltage single phase alternating current on the high voltage side, The power can be distributed, via a cable, to one or more power receiving stations PRS. The cable is configured to distribute current-symmetrical single phase current delivered by the power feeding station. The cable can preferable be a coaxial cable with the shield as current return path. The invention also comprises a current sensor unit CSU which is situated on the high voltage side. The means for measuring characteristics of the current CD can comprise a coil without galvanic contact with the high voltage side. A circuit break unit CBU suitable for breaking the current is situated on the low voltage side.

Abstract: A device for limiting loads on towers that limits loads only in the longitudinal direction and does not affect the manner in which vertical and transverse loads are resisted by the structure. The device incorporates a shield to prevent ice buildup that could affect its operation. It also has optional antifriction bearings to provide a consistent release force independent of the amount of ice that may accumulate on the wires. The device is of simple construction. The device includes an optional energy absorber, such as that used in U.S. Pat. No. 3,211,260 that can provide a resisting force that is within the longitudinal strength of the tower. The device includes both a mechanical fuse and an energy absorbing mechanism that is used to arrest the wire movement. The energy absorber can extend as much as 50 ft to safely absorb the energy released by broken wires with heavy ice coatings.

Abstract: Dead-end-to-dead-end overhead electrical power transmission line with at least two different conductors, and method of selecting and installing the conductors.

Abstract: A signal shielding box with a plurality of shielding covers is provided. The shielding covers are pivotally connected with a shielding case and cover one another so as to respectively conceal or expose the opening. A connector is positioned at the shielding case and is electrically connected with the wireless communication device within the shielding case. The connector is electrically connected with a measurement and analysis device out of the shielding case. The shielding covers are respectively opened and closed so as to expose and conceal the opening. Thus, a plurality of shielding effects are formed so as to shield and measure signals of the wireless communication device.

Abstract: A high frequency signal transmission line having reduced noise. Particularly, a signal transmission line of the current invention has reduced radiation noise and reflection noise, because a conventional ground guard fence line disposed between signal lines is separated into a plurality of ground line blocks that are spaced apart from each other to shield against noise.

Abstract: A support assembly for supporting a high voltage electrical conductor suspended from a lattice-type tower during maintenance and repair includes a pair of elongate support arms, each of the support arms having an aperture extending therethrough intermediate its ends, the aperture opening in a direction transverse to the length of the support arms, and an elongate conductor support bar slidably received in the apertures of the support arms and extending between the support arms to define with the support arms a generally H-shaped support assembly, the support arms being slidable on the support bar for adjusting the distance between the arms and being movable on the support bar between a first position wherein the arms are parallel to each other and a second position wherein the arms are arranged at an angle to each other.

Abstract: A motor controller includes: an estimated temperature calculating section that calculates and stores an estimated temperature of a motor, and a control section that can perform a drive control of the motor only when this estimated temperature is not larger than a predetermined value. When the motor is stopped, a second temperature gradient while the temperature of the motor decreases from a stop-time temperature to a predetermined first set temperature is stored in correspondence to the stop-time temperature. The first temperature gradient corresponding to the estimated temperature at a time when the motor is stopped is calculated by using the first temperature gradient storing means, if the estimated temperature stored in the estimated temperature storing means when the motor is stopped is larger than the first set temperature.

Abstract: The present invention provides a set of circuits which is capable of performing an automatic check on main components of a circuit interrupting device when the circuit interrupting device is properly powered and the device is at a tripped state to determine whether these main components function normally. The results of the automatic check can be detected by depressing a reset button in the circuit interrupting device. If the reset button can be depressed, the main components function normally. Alternatively, the results can be automatically displayed by a showing on the face lid of the circuit interrupting device of either a green light, which means that the main components function normally, or a red or yellow light or no light, which means that at least one of the main components in the circuit interrupting device does not function properly.

Abstract: The present invention provides a circuit interrupting device, preferably a ground fault circuit interrupter (GFCI), which contains a dual-function test button having a short pole and a long pole positioned underneath the dual-function test button. When the GFCI is properly wired and powered, a depression of the dual-function test button allows the short pole to operatively connect to a conductive pin and generate a leakage current to test the components of the GFCI. If all of the components are functioned properly, the GFCI can be reset. If not, the GFCI cannot be reset. When the GFCI is miswired or reverse wired and not powered, a depression of the dual-function test button does not test the components of the GFCI. However, a further depression of the dual-function test button allows the long pole presses against a tripping lever on a locking member in a tripping device which mechanically trip the GFCI.

Abstract: An audio compensation system (20) for producing a sound compensated output signal (So). The system comprises a volume control circuit (24) for producing a volume-adjusted signal (Sic) by applying a volume adjustment to an audio signal in response to a volume setting, wherein the sound compensated output signal is responsive to the volume-adjusted signal. The system also comprises circuitry (26, 30, 32) for producing an amplified signal (Sifa) by amplifying a selected bandwith of signals in response to the volume setting. The sound compensated output signal is also responsive to the amplified signal.

Abstract: Three single-phase transformers are provided, the primary sides connected in a Wye configuration. One terminal on the primary side of each transformer is coupled to a reference node and the other terminal on the primary side of each transformer is coupled to one phase of the power supply bus. The secondary sides of the transformers are connected in a delta configuration through a resistor. The circuit connecting the secondary sides of the transformers is not electrically connected to ground.

Abstract: A distributive capacitor 205 and impedance matching network 201 and transmitter 101 that use the capacitor and are suitable for high density integration applications include a printed circuit substrate 303 comprising one of a printed circuit board and a silicon based substrate, a first conductive layer 305 disposed on the printed circuit substrate, a layer of dielectric material 307 disposed on the first conductive layer and having a thickness, the dielectric material having a dielectric constant more than five times greater than the dielectric constant of the printed circuit substrate; and a second conductive layer 309 disposed on the layer of dielectric material and having a second length 311 and a second width 603 that are selected so that the distributive capacitor operates as a transmission line.

Abstract: A distributive capacitor 205 and impedance matching network 201 and transmitter 101 that use the capacitor and are suitable for high density integration applications include a printed circuit substrate 303 comprising one of a printed circuit board and a silicon based substrate, a first conductive layer 305 disposed on the printed circuit substrate, a layer of dielectric material 307 disposed on the first conductive layer and having a thickness, the dielectric material having a dielectric constant more than five times greater than the dielectric constant of the printed circuit substrate; and a second conductive layer 309 disposed on the layer of dielectric material and having a second length 311 and a second width 603 that are selected so that the distributive capacitor operates as a transmission line.

Abstract: A grounding and testing device for power distribution systems includes an electrically insulated housing with a bore that extends from an aperture at a front of the housing towards a rear of the housing. An electrical contact is disposed at least partially within the bore, and the bore, aperture, and conductive contact are adapted to mate with a bushing. A current interrupter, such as a current limiting fuse, is electrically connected between the contact and a grounding cable. An annunciator is connected to the current interrupter such that the annunciator provides an indication when a current flows through the current interrupter. A lead is electrically connected to the contact to provide a connection point for a permanent ground connection.

Abstract: A hybrid semiconductor circuit adjustable by a control current for controlling voltage comprising a single high-voltage reversely polarized diode surrounded by at least two diodes emitting infrared radiation fed in series by the control signal and arranged to allow optical interaction with the high-voltage diode, wherein the diodes are encapsulated with a coating resin having a high transmission rate in an infrared domain.

Abstract: A protective system for reducing the possibility of injury to individuals or damage to electrical equipment due to a fault in a coaxial drop cable connected between a tap unit receiving both RF signals and AC power from a main distribution line and a premise unit coupling the RF signals to RF receiving equipment and the AC power to other AC powered equipment at user premises. The tap unit includes a circuit having a first line connected at spaced points to an inner conductor with the RF signals flowing through the inner conductor and the AC power flowing through the first line. A regulated monitoring current flows from an AC to DC converter in the first line to a difference amplifier having a pair of inputs with a resistor connected between the two, whereby the difference amplifier serves to monitor the monitoring current by measuring the voltage drop across the resistor.

Abstract: An arc-fault detecting circuit-breaker system includes a normally closed line circuit breaker in series with a protected electrical circuit element whose current flow is to be interrupted upon the occurrence of an arc fault. A detector senses the rate of change with time of the current flow in the protected electrical circuit element. A silicon-controlled rectifier has a gate of the silicon-controlled rectifier in electrical communication with a detector output signal of the detector. The silicon-controlled rectifier shorts the current flow in the protected electrical circuit element in the event that the detector output signals that the rate of change of current with time in the protected electrical circuit element is in excess of a permitted maximum rate-of-change value, thereby activating the line circuit breaker.

Abstract: A less expensive power cord with a safety device detects the damage of the power lines in a cord at an earlier stage, shuts off the power, and guarantees the safety of an electric appliance and its environment. The power cord has two power lines and a detection line provided between them, and the sheath portion between the detection line and the power line is thinner than the insulating sheath material of the cord contact portion. When the power line becomes half-broken and damaged by the fatigue with the passage of time due to bendings and pulls, the broken ends of the thin lines of the power line are untwisted and contact the thin sheath portion of the detection line, a current flows through the detection line, a current difference occurs in the power line, the power shutdown device detects the difference, releases a latch, and opens a constant close interlocking switch, thereby shutting off the power.

Abstract: A coaxial surge protector includes a housing in which is situated a transmission line in the form of a two-sided printed circuit board. The surge protector includes input and output signal connectors mounted on a housing and connected to the transmission line, and a gas discharge tube electrically coupled between the transmission line and circuit ground. A thermally activated shunt assembly is thermally coupled to the gas discharge tube and senses when the gas discharge tube is in an overheating condition. Upon such condition, the shunt assembly provides an electrically conductive shunt in parallel with the gas discharge tube to divert current flowing through the gas discharge tube to flow through the shunt assembly to ground in order to minimize further overheating of the gas discharge tube.

Abstract: A surface mounted receptacle assembly for use in a motor vehicle having a cabin includes a cover, a mounting plate adapted to be mounted to the vehicle, a wire harness and a backing plate removably secured to the cover to conceal at least a portion of the wire harness wherein the cover is selectively attachable to the mounting plate.

Abstract: A data surge protection module can be added to data and control networks not having such surge protection. The use of quick connect/disconnect connectors allows for the rapid installation and/or replacement of such modules. A built-in ground plate and a braided low impedance conductor offer alternative grounding for the module. The module employs two or more diode steering bridges and uses a diode as a surge suppression element.

Abstract: A broadband coaxial overvoltage protector includes a short-circuit line segment connected in parallel with a coaxial line section, a transforming coaxial line section with a length <&lgr;/4, with one end of the transforming coaxial line section connected in series to the coaxial line section, and an open-circuit line segment connected in series to the other end of the transforming line section. The length of the transforming line section is selected in such a way that the curve representing the frequency dependence of the reflection coefficient for two different operating frequencies, which may be widely spaced, has a respective minimum at each of the two frequencies.

Abstract: A multi-potential guarding technique for preventing electrical charge exchange to or from an electrical system containing potential gradients and sources of electrical noise. An inner electrically conductive guard shield surrounds the system to be guarded. The electrical potential of the inner electrically conductive guard shield is such that there is ideally no net current flow to the guard shield from the electrical system therewithin. An outer electrically conductive guard shield surrounds the inner electrically conductive guard shield. An operational amplifier drives the outer electrically conductive guard shield to an electrical potential that is substantially equal to that of the inner electrically conductive guard shield so that there is substantially no potential difference between the inner and outer guard shields which has the effect of producing a high insulation impedance around the guarded system.

Abstract: A protector which is coupleable with a coaxial transmission line. The protector includes a gas tube assembly. The gas tube assembly has a first electrode which is coupleable with the inner conductor of the coaxial transmission line such that the first electrode becomes substantially aligned with the transmission line. The gas tube assembly also includes a second electrode which is coupleable with the outer conductor of the coaxial transmission line. Each of the first and second electrodes of the gas tube assembly has a discharge area, and the discharge areas are spaced apart from each other. A body portion is attached to the discharge areas defining a sealed chamber therebetween.

Abstract: A protective overload device (POD) that absorbs energy and reduces the damage to transmission towers resulting from sudden conductor, shield wire, insulator, or conductor suspension failures is herein disclosed. The POD is positioned between the non-energized end of the insulator and the tower or support structure, or between the energized end of the insulator and the conductor. The POD consists of a top lid, a bottom plate, and a ductile load fuse refill disk. The top lid is slotted at regular intervals to allow for transverse deformation of the individual fingers that hold the bottom plate. The ductile load fuse refill disk consists of a filler material in which a steel cable is embedded. The POD acts as a passive rigid link under normal conditions. In the event of a dynamic shock that could fail a tower or tower arm, the fingers of the top lid will move outward along the sliding plane of the bottom plate until the bottom plate separates from the top lid.

Abstract: A current limiter arrangement particularly adapted to be positioned at a substation of an electrical power system for limiting the fault current for a predetermined period of time to permit protective devices positioned downstream in the network to clear the fault. If the fault is not cleared and the fault persists for a predetermined period of time the current limiting arrangement acts as a circuit breaker to open the load circuit. The arrangement includes an SCR bridge having a superconducting coil connected across two nodes. A novel gate pulse firing circuit generates two pulses per ac cycle for application to the gates of the SCR's of the bridge at 90.degree. and 270.degree. of each 360.degree. cycle and is ON at all times to provide for prompt dc charging of the super conducting coil with no ac load current and non-fault conduction of ac current at less than the maximum current limit.

Abstract: A coaxial drop cable safety device is used for cable television, data and telephony applications. The device is used on buried drop cable where 60 Hz powering voltages applied to the drop cable exceed low voltage safety limits and where the drop cable is buried at depths which is less than the minimum required to meet electrical safety codes. Tap end and premise end units are connected to the drop cable. The tap end unit applies a DC voltage to the center conductor of the drop cable. A monitoring circuit in the tap end unit monitors the center conductor DC voltage to a fault from the center conductor to ground along the drop cable. The tap unit will immediately remove the powering voltage In the event of either an open or faulted condition on the center conductor along the entire length of the drop cable.

Abstract: The present invention features a method and an apparatus for distributing electrical power from a power source to a distribution transformer, using at least one hot-phase conductor, a neutral conductor and an independent ground conductor. The neutral conductor is connected to the ground conductor at only one point in the distribution system, preferably at or near the power source. Normal imbalance current flows only in the neutral conductor. Return current flow in the earth is eliminated by the single point neutral-to-ground connection. Magnetic field (MF) generation in this power distribution system is thus reduced and stray voltage problems eliminated. In addition, high-impedance faults are easily detected because the only current ever flowing in the ground conductor is fault current. A method is also described for converting existing power distribution systems to the independent ground topology of the present invention.

Abstract: A surge protector (1) for a coaxial transmission line is constructed with a pair of coaxial connectors (2) mounted on a conducting hollow body (4), and a transmission line conductor (3) with a resilient beam portion (12) to engage and urge a surge protection element (5) against the hollow body (4).

Abstract: A method and apparatus for suppressing surges in an electrical power distribution system utilizing stripline techniques. The apparatus includes an input terminal which connects a phase electrical power source to a TVSS device. A stripline circuit connects the input terminal to the TVSS device to greatly reduce the inductance of the connection. Consequently, the clamping voltage rating of the TVSS device is substantially maintained at the input terminal during the occurrence of a power surge.

Abstract: A power transmission system includes a transmission line unit for three phases connected to three gas insulated transmission lines and a standby transmission line unit for a phase connected to a standby gas insulated transmission line connected with each other. A connection bus is provided at a branch part of each breaker in the transmission line unit for three phases, via the breaker. The connection bus is connected to a branch bus provided between the breaker in the transmission line unit of a gas insulated switch gear for three phases and the main buses, and to the standby transmission line unit.

Abstract: A broadband communications network having an uninterruptible power supply. The power supply has one input connected to AC line voltage and another input connected to a gas powered electrical generator. The power supply contains an uninterruptible power supply module having a controlled ferroresonant transformer and a battery. The power supply also contains a bypass module having a controlled ferroresonant transformer. Switches are provided to allow either of the inputs to be connected to either the UPS module or the bypass module for the generation of power signals for supplying power to the broadband communications network.

Abstract: A protection arrangement for an electronic device sensitive to electromagic radiation comprises a single printed circuit board which is disposed within a metal casing so that it passes perpendicularly through a metal partition separating an upstream zone in which electromagnetic fields prevail from a screened downstream zone, the board thus having a first part situated in the upstream zone and a second part, which is intended to carry the electronic device, situated in the downstream zone. Electrical signals are conveyed from the upstream zone to the downstream zone by means of conductive lines printed on at least one inner layer of the printed circuit board, and the board is provided with means for filtering the electrical signals comprising surface-mounted components in the vicinity of the metal partition and capacitive elements integrated in the printed circuit board where it passes through the partition.

Abstract: Apparatus and method are supplied for an electrical power substation used to interconnect an input three-phase power line to one or more poly-phase output distribution power lines. The teaching of the subject application shows that parasitic losses in prior art substation wiring that uses coaxial cables to conduct power into and out of the substation can be reduced by using an individual grounding rod for each outer conductor instead of following conventional practice and connecting all three conductors together at a common grounding rod. Moreover, if the three input coaxial cables to the distribution substation or the three output coaxial cables from the substation have the current in a center conductor precisely matched to the return current in the associated outer conductor, there will be neither an electric potential gradient nor a magnetic intensity outside of the transmission lines.

Abstract: The method of power transmission and distribution aims to mitigate the magnetic fields generated at a right of way and at distances which extend beyond the right of way. The transmission and distribution lines use various line parameters including the relative locations of the conductors around the axis of symmetry of the right of way, the current magnitudes and the phase angles of the currents flowing in the conductors in optimum asymmetric fashion. The use of magnetic field mitigation bodies placed adjacent to the current bearing conductors increases the scope and the effectiveness of the mitigation. A mitigation technique is also provided for mitigating the magnetic field generated by current bearing sources used in power distribution, with unknown or difficult to characterize current distributions, such as transformers.

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.

Abstract: A thyristor controlled series capacitor (TCSC) system, including a method and apparatus, uses phase controlled firing based on monitored capacitor voltage and line current. For vernier operation, the TCSC system predicts an upcoming firing angle for switching a thyristor controlled commutating circuit to bypass line current around a series capacitor. Each bypass current pulse changes the capacitor voltage proportionally to the integrated value of the current pulse. To damp the natural oscillatory response of the inductive commutating circuit and the capacitor, a bypass mode firing angle is introduced to create a nonlinear response. The harmonic distortion on the commutating circuit current waveform is determined from the capacitor voltage, which is then used to determine the magnitude of the firing angle. Preferably the firing angle magnitude decreases in response to decreasing capacitor voltage, eventually returning to steady-state conditions.

Abstract: A series-capacitance compensated shielding circuit is located physically adjacent and parallel to a polyphase power transmission line for the purpose of partially cancelling the electromagnetic fields created by current flow through the transmission line. The shielding circuit forms a loop circuit around substantially the entire transmission line or a portion thereof, and is positioned such that a current is induced therein by the magnetic field produced by the alternating currents in the transmission line. Such induced current is tuned by the series capacitance to produce an optimized cancelling magnetic field, thus reducing the net electromagnetic fields created by the power lines along a right-of-way.

Abstract: A grounding device is automatically operable to create a short circuit in the event of a mechanical fault on a pole line. The grounding device is placed below, and close to, each phase line on a pole line. When the phase line moves down, because of a broken wire or the like, the wire engages a sensing member which moves down and causes projection of a grounding tongue. The sensing member has surfaces that direct the wire to a contact area; and, the wire moves the sensing member down, causing projection of a grounding tongue, which will contact the phase line. Before actuation, the tongue, and all portions at ground potential, are enclosed within an insulating housing. A transmitter may also be actuated to broadcast the location of the grounding device.

Abstract: Extraneous electric and magnetic fields, which may be public health risks associated with electric power transmission, are avoided by using an improved power transmission cable and wiring arrangement that uses coaxial transmission lines configured so that the return current flows in the outer conductor. A cable structure is taught that both provides the desired shielding and maintains protection against lightning strikes. The coaxial transmission lines eliminate radiation of 50-60 Hz electromagnetic waves.