Abstract: An object of the present invention is to provide an ESD protection device and the like which offer a reduced discharge starting voltage and improved durability against repeated use. The present invention provides an ESD protection device including a base 2 having an insulating surface 2a, electrodes 3a and 3b disposed on the insulating surface 2a and facing but spaced apart from each other, and a functional layer 4 disposed on at least between the electrodes 3a and 3b, wherein the gap distance ?G between the electrodes 3a and 3b ranges from 0.5 ?m to 10 and the thickness ?T of each of the electrodes 3a and 3b meets a relationship of ?G/?T=1 to 30.

Abstract: Disclosed is a chip scale gas discharge protective device whose metal coupled electrodes are fabricated through processes of yellow light, image formation, and electro casting of metal electrode, and the two electrodes are facing each other in arch lines with the distance of a gap controlled within the range of 0.5˜10 ?m, wherein the entire structure is performed by a bridge process without an extra gas filling procedure in the gap. Due to the fact that the gap is as small as only several ?m, a relevant potential difference existing across there is sufficient to ionize the air thereby suppressing the electro-static discharge (ESD) through the protected electronic device, whereas the fabrication method is disclosed.

Abstract: A housing encapsulating first and second terminals of a surge arrester disconnector becomes structurally weakened before activation of a disconnect device in the disconnector when the disconnector is exposed to heat, thereby preventing the disconnector from producing a projectile with a force sufficient to classify the disconnector as a hazardous material under Department of Transportation regulations.

Abstract: A gas-filled surge arrester includes at least two electrodes, a gas filling and an activating compound applied to at least one of said electrodes. The activating compound can include: (i) nickel powder in an amount of about 10% to about 35% by weight; (ii) potassium or sodium silicate in an amount of about 20% to about 40% by weight; (iii) titanium powder in an amount of about 5% to about 25% by weight; (iv) calcium titanium oxide in an amount of about 5% to about 15% by weight; and (v) sodium bromide in an amount of about 10% to about 20% by weight. Ignition striping process and resulting stripes from ink-jetting of striping material are disclosed.

Abstract: An ESD protection device includes a ceramic multilayer board, a cavity disposed in the ceramic multilayer board, at least one pair of discharge electrodes having ends, edges of the ends being opposed to each other at a predetermined distance in the cavity, and external electrodes disposed on outer surfaces the ceramic multilayer board and connected to the discharge electrodes. The ceramic multilayer board includes a composite portion, which is disposed in the vicinity of the surface on which the discharge electrodes are disposed and is at least disposed adjacent to the opposed ends of the discharge electrodes and to a space between the opposed ends. The composite portion includes a metal material and a ceramic material.

Abstract: The provided is an electrostatic discharging (ESD) inducing apparatus in a mobile communication terminal with a fingerprint recognition function. The ESD inducing apparatus includes: a fingerprint recognizing unit for obtaining fingerprint information by contacting with a fingerprint of a human finger, which is provided to one side of the mobile communication terminal; a printed circuit board provided with a mounting unit contacting with the fingerprint recognizing unit for receiving the fingerprint information from the fingerprint recognizing unit; and a ground unit for inducing a static electricity caused by contacting with the fingerprint, which is provided to the printed circuit board adjacent to the mounting unit.

Abstract: An apparatus, system, and method provide electrostatic discharge (ESD) protection in electronic devices by guiding electrostatic charges to a ground through ESD channels within electrical insulation sheet. The ESD channels are positioned within the electrical insulation sheet to provide electrical paths to ground having a lower impedance than electrical paths to protected areas covered by the electrical insulation sheet. Accordingly, an ESD follows the path of least resistance safely to ground rather than to a critical component within the electronic device. In the exemplary embodiment, the ESD channels are openings in a dome contact layer of a keypad where the openings are positioned over one or more ground areas of a printed circuit board (PCB) and the insulting material of the dome contact layer covers areas of the PCB that are protected from ESD. By implementing dedicated GPIO lines, grounded metal domes cover the signal pads in the target discharge area to protected the GPIO lines from ESD.

Abstract: A method for accessing an electronic circuit in an enclosure using near field induction is disclosed. The method involves attaching at least one local access port connector with an external transformer core partition to a near field induction port on an external non-conductive surface of a panel of the enclosure and generating at least one inductive field between the external transformer core partition and an internal transformer core partition. Without a direct electrical connection, the method provides for communicating with the electronic circuit through the at least one local access port connector of the panel using the at least one inductive field.

Abstract: A device for safe dissipation of static electricity or charge from an object, comprising at least one conductive contacting means intended to be applied in contact with the object and to be connected to a point capable of dissipating electric current. The contacting means is connected to the dissipation point via a low conductive material for slow dissipation of current from the object, such that the formation of sparks is avoided. Preferably, the low conductive material comprises an insulating matrix, such as plastics, and a conductive additive mixed therein, such as metallic powder or soot. A potential recharging of the object will then be dissipated relatively slowly during initial contact with the device such that no spark can be released. Thereby, an explosion or fire can be avoided in hazardous environments, particularly in the field of chemical industry.

Abstract: An apparatus, system, and method provide electrostatic discharge (ESD) protection in electronic devices by guiding electrostatic charges to a ground through ESD channels within electrical insulation sheet. The ESD channels are positioned within the electrical insulation sheet to provide electrical paths to ground having a lower impedance than electrical paths to protected areas covered by the electrical insulation sheet. Accordingly, an ESD follows the path of least resistance safely to ground rather than to a critical component within the electronic device. In the exemplary embodiment, the ESD channels are openings in a dome contact layer of a keypad where the openings are positioned over one or more ground areas of a printed circuit board (PCB) and the insulting material of the dome contact layer covers areas of the PCB that are protected from ESD. By implementing dedicated GPIO lines, grounded metal domes cover the signal pads in the target discharge area to protect the GPIO lines from ESD.

Abstract: An anti-surge power adapter comprising: a transformer; a pair of copper sheets which, with a certain gap between themselves, is connected between said transformer and the power input terminal or on the said transformer to release instantaneous surge. The present invention features low cost, simple process and high reliability, and only requires two copper sheets or a PCB or other insulating board with copper sheets to be connected in the circuitry. The anti-surge power adapter uses copper sheets to release instantaneous high voltage, features quick response and can withstand an instantaneous high voltage of 6-17 KV. This invention is applicable to linear or switching power adapter.

Abstract: A system for protecting a composite-body aircraft from damage caused by lightning strikes includes a Faraday cage defined on the exterior surface of the aircraft body by a continuous, electrically conductive grid that extends to the outermost lateral periphery of the body. In one possible embodiment in which the aircraft's body includes a plurality of composite panels that are joined at their adjacent edges by splice plates, the conductive grid may advantageously be formed by electrically conductive splice plates, e.g., of titanium, that have their respective, adjacent ends electrically connected to each other, e.g., with conductive straps and fasteners. The conductive grid provides preferential attachment points and conductive paths for lightning strikes on the surface of the aircraft, thereby shielding the interior of the grid from lightning damage. The conductive grid can optionally function as a ground return path for the aircraft's electrical system.

Abstract: A surge discharging device for releasing electric surge due to high voltage so as to avoid destroy of an electric apparatus having the device, the surge discharging device comprises a body having a hollow space; a channel connected between the hollow space and an exterior of the body; two terminals spaced at two sides of the hollow space; front ends of the terminals being exposed in the hollow space and rear ends of the terminals being exposed out of the body. The body includes a first enclosure and a second enclosure. A plurality of connecting bars are extended from the first enclosure; and the second enclosure is formed with a plurality of connecting holes. An inner wall of each of the first enclosure and the second enclosure has a recess; as the first enclosure and the second enclosure are combined, the two recesses are formed as the hollow space.

Abstract: A housing encapsulating first and second terminals of a surge arrester disconnector becomes structurally weakened before activation of a disconnect device in the disconnector when the disconnector is exposed to heat, thereby preventing the disconnector from producing a projectile with a force sufficient to classify the disconnector as a hazardous material under Department of Transportation regulations.

Abstract: An antenna diode circuit for discharging static charge accumulated during wafer processing is described. The antenna diode circuit includes first and second junctions coupled to a circuit element and substrate. Between the first and second junctions is a diode circuit path with an antenna diode and at least one diode protection circuit coupled in series. The diode protection circuit reduces or prevents EOS current from flowing through the diode circuit path during an EOS event.

Abstract: A capacitor structure having a dielectric layer disposed between two conductive electrodes, wherein the dielectric layer contains at least one charge trap site corresponding to a specific energy state. The energy states may be used to distinguish memory states for the capacitor structure, allowing the invention to be used as a memory device. A method of forming the trap cites involves an atomic layer deposition of a material at pre-determined areas in the dielectric layer.

Abstract: One embodiment in accordance with the invention includes a capacitive sensor apparatus that includes a sensing element and a ground element. The capacitive sensor apparatus also includes a floating strike ring that is electrically isolated from the sensing element. The floating strike ring and the ground element form a spark gap. The spark gap is for reducing potential damage to the capacitive sensor apparatus that can be caused by an electrostatic discharge encountered by the capacitive sensor apparatus.

Abstract: A capacitor structure having a dielectric layer disposed between two conductive electrodes, wherein the dielectric layer contains at least one charge trap site corresponding to a specific energy state. The energy states may be used to distinguish memory states for the capacitor structure, allowing the invention to be used as a memory device. A method of forming the trap cites involves an atomic layer deposition,of a material at pre-determined areas in the dielectric layer.

Abstract: A downhole tool includes a device to be activated by electrical energy and a micro-switch that includes conductors and an element between the first and second conductors selected from the group consisting of: a dielectric element capable of being modulated to provide a conductive path in response to receipt of electrical energy; and an element moveable in response to application of an electrical energy. The micro-switch may be formed of microelectromechanical system (MEMS) technology or microelectronics technology.

Abstract: A waveguide which is particularly suitable for transmitting electrical signals between or to and/or from electronic circuits, for example between integrated circuits disposed on a printed circuit board, has an over-voltage protection region. The over-voltage region of the waveguide region is specifically formed by the actual geometric configuration of the waveguide.

Abstract: Surface mounting caps 14 are placed onto both ends of a cylindrical housing 12 of a surge absorber element 10. The surface mounting cap 14 is formed by pressing a phosphor bronze plate, and comprises a cap bottom section 30 and a flange section 16. The flange section 16 grabs the outer peripheral end of the cylindrical housing 12 and lead lines 26 of the surge absorber element 10 are snapped and maintained by a binding section 38 provided at the cap bottom section 30.

Abstract: An overvoltage protection device for an electronic apparatus having a plug-in device which has at least one plug-in element and is designed for insertion into a housing of the electronic apparatus. In overvoltage protection in which there is no need for any additional shielding measures from the electronics, a protection board which has a spark gap in order to dissipate overvoltages is arranged on the plug-in element.

Abstract: The invention relates to a circuit array with an antenna input (1), a signal input (2) and a signal output (3), and having a switch unit (4) which has a control line (5), with which the optional connecting of the antenna input (1) to the signal input (2) or the signal output (3) can be controlled, in which the antenna input (1) is connected to a first protective device (6) against electrostatic discharges and the control line (5) to a second protective device (7) against electrostatic discharges. As a result of the protective device in the control line, the ESD safety of the circuit array can be improved. The invention also relates to a circuit module and its use as a front-end module in a mobile telephone.

Abstract: The invention relates to a spark gap arrangement for use in power supply systems, especially in low-voltage systems, comprising an arcing chamber in which an electric arc is formed between two electrodes of the spark gap. An intermediate chamber (5) is provided downstream of the arcing chamber (3). Said intermediate chamber has a much greater volume than the arcing chamber (3). A pressure-proof flow channel (4), preferably consisting of metal, is provided as the connection between the arcing chamber (3) and the intermediate chamber (5).

Abstract: An electrostatic discharge device (ESD device) of the surface mount type and a method of fabricating such devices are disclosed. The ESD device includes an upper cover plate made of an insulating material, a middle insulating plate made of an insulating material and laminated on the lower surface of the upper cover plate, and having a discharge opening, with first and second discharge terminals formed in the middle insulating plate at opposite edges of the discharge opening, and a lower cover plate made of an insulating material and laminated on the lower surface of the middle insulating plate, and hermetically sealing the discharge opening of the middle insulating plate in cooperation with the upper cover plate, and having a second signal electrode brought into electric contact with the first discharge terminal, and a second ground electrode brought into electric contact with the second discharge terminal.

Abstract: An electronic component is described and has a dielectric layer which is constructed on a substrate, conductive surfaces that are constructed on the dielectric layer, and an electrically conductive guard structure. The guard structure is disposed in a plane above the conductive surfaces such that the conductive surfaces are not completely covered by the guard structure.

Abstract: In a production system included in a power modulator for the protection of a load connected to the power modulator, comprising a charging system, a power impulse former, a control arrangement and a pulse transformer with a first protection circuit in the form of a crowbar circuit connected to the input side and the load connected to the output side of the pulse transformer, a second protection circuit is connected to the output side of the pulse transformer between the low potential and the ground potential connections thereof wherein the second protection circuit includes a controlled switch with a resistor arranged in parallel therewith.

Abstract: Disclosed is an optical disc drive sharing switching device, method and associated application system. The optical disc drive sharing switching device integrates a personal computer and an optical disc player together inside an information-processing appliance. The personal computer and the optical disc player share the use of an optical disc drive. The user is free to switch connections between the personal computer and the optical disc player with the optical disc drive. The device uses a simple switching program and the computer functions normally even if the optical disc drive is not under its control.

Abstract: The present invention relates to a passive electronic component architecture employed in conjunction with various dielectric and combinations of dielectric materials to provide one or more differential and common mode filters for the suppression of electromagnetic emissions and surge protection. The architecture allows single or multiple components to be assembled within a single package such as an integrated circuit or connector. The component's architecture is dielectric independent and provides for integration of various electrical characteristics within a single component to perform the functions of filtering, decoupling, fusing and surge suppression, alone or in combination.

Abstract: A chip-type surge absorber and method for producing same, wherein the chip-type surge absorber includes an insulating substrate in the shape of a rectangular parallelepiped; an insulating hermetic cap open at a bottom side thereof, for forming, together with the insulating substrate, a box-shaped hermetically sealed cavity filled with a discharge gas; terminal electrodes disposed at both ends in the hermetically sealed cavity; a pair of discharge electrodes which are formed in the hermetically sealed cavity such that a discharge gap is formed between the discharge electrodes and such that the discharge electrodes are electrically connected to corresponding terminal electrodes; and connection surfaces for increasing the connection area for the connection between the discharge electrodes and the terminal electrodes.

Abstract: The present invention provides an over-voltage surge protection device comprising a printed circuit board having a signal carrying conductive member having a plurality of nodes positioned therealong, and a conductive member running to ground also having a plurality of nodes positioned therealong. The nodes on the signal carrying member and ground member extend along a common path with corresponding ones of the signal carrying nodes positioned in adjacent, but spaced relation to the ground nodes. Preferably, the nodes are shaped in the form of triangles due to this particular geometry's favorable ability to accumulate and discharge voltage.

Abstract: A chip-type surge absorber and method for producing same, wherein the chip-type surge absorber includes an insulating substrate in the shape of a rectangular parallelepiped; an insulating hermetic cap open at a bottom side thereof, for forming, together with the insulating substrate, a box-shaped hermetically sealed cavity filled with a discharge gas; terminal electrodes disposed at both ends in the hermetically sealed cavity; a pair of discharge electrodes which are formed in the hermetically sealed cavity such that a discharge gap is formed between the discharge electrodes and such that the discharge electrodes are electrically connected to corresponding terminal electrodes; and connection surfaces for increasing the connection area for the connection between the discharge electrodes and the terminal electrodes.

Abstract: A surge-gap device (300) includes two electrodes (310, 315), having an inside portion and an outside portion, and an insulator material (320), which secures the two electrodes (310, 315). The insulator material (320) has an opening through the material to expose an open-air gap (325) that is defined by the space between the two inside portions of the electrodes (310, 315). In cases of a voltage surge, the surge-gap device permits an arc to pass between the proximate inside portions of the electrodes (310, 315) across the open-air gap (325), which gives a current surge a low impedance path to ground. Also included is a fastener (305) for electrically coupling the surge-gap device (300) to a ground plane (220) of an external electrical device (300) for suppressing the voltage and current surges.

Abstract: The invention relates to a surge absorber provided with; a surge absorber element composed of a columnar non-conductive member and a conductive film formed dividedly via a discharge gap on a peripheral surface of the non-conductive member, a pair of sealing electrodes disposed at opposite ends of the surge absorber element and touching the conductive film, and a glass tube with opposite ends closed by the sealing electrodes, and the surge absorber element and an inert gas encapsulated thereinside. In the surge absorber of the invention, a face of each sealing electrode which contacts with the surge absorber element is formed in a concave shape symmetrical with a central axis of the glass tube. As a result the surge absorber element can be positioned in the center of the glass tube with high accuracy, the life span and the surge current capacity of the surge absorber can be improved, and low cost and small size becomes possible.

Abstract: An overvoltage protection element for diverting transient overvoltages, with two electrodes (3, 4), each of which has a current terminal (1, 2), an air-breakdown spark gap (5) between the electrodes (3, 4) and a housing (6) which holds the electrodes (3, 4). The overvoltage protection element with an air-breakdown spark gap (5), with reference to the operating voltage, the lightning surge current and network follow current carrying capacity behavior and the network follow current extinguishing behavior meets current requirements in a special way by the electrodes (3, 4) being located parallel to one another.

Abstract: A protective device for deflecting or reducing short duration, large current, electromagnetic impulses which may occur along a RF cable while allowing desired RF signals to pass through comprises in one embodiment an outer conductor having a main body section, a first connector and a second connector. The main body section is cylindrically shaped, has a cylindrically shaped inner sidewall and includes a first end and a second end. The first connector extends out from the first end of the main body section. The second connector extends out from the second end of the main body section. An inner conductor is axially disposed within the outer conductor and extends through the main body section into the first and second connector interface. Insulators provided for mechanically supporting and electrically insulating the inner conductor from the outer conductor.

Abstract: An electrostatic discharge device (ESD device) of the surface mount type and a method of fabricating such devices are disclosed. The ESD device includes an upper cover plate made of an insulating material, a middle insulating plate made of an insulating material and laminated on the lower surface of the upper cover plate, and having a discharge opening, with first and second discharge terminals formed in the middle insulating plate at opposite edges of the discharge opening, and a lower cover plate made of an insulating material and laminated on the lower surface of the middle insulating plate, and hermetically sealing the discharge opening of the middle insulating plate in cooperation with the upper cover plate, and having a second signal electrode brought into electric contact with the first discharge terminal, and a second ground electrode brought into electric contact with the second discharge terminal.

Abstract: The invention relates to an overvoltage protection device for an electronic apparatus having a plug-in device which has at least one plug-in element and is designed for insertion into a housing of the electronic apparatus. In overvoltage protection in which there is no need for any additional shielding measures from the electronics, a protection board which has a spark gap in order to dissipate overvoltages is arranged on the plug-in element.

Abstract: Surface mounting caps 14 are placed onto both ends of a cylindrical housing 12 of a surge absorber element 10. The surface mounting cap 14 is formed by pressing a phosphor bronze plate, and comprises a cap bottom section 30 and a flange section 16.

Abstract: An overvoltage protection system with an overvoltage protection element (1) and an ignition aid which triggers the overvoltage protection element (1), the overvoltage protection element (1) having two main electrodes (2, 3) and an air-breakdown spark gap (4) which acts between the main electrodes (2, 3). An overvoltage protection system having a relatively small and also largely constant operating voltage is implemented by there being an ignition circuit (5) with an ignition voltage output (6) as the ignition aid, the overvoltage protection element (1) having an ignition spark gap (7) which acts between the main electrodes (2, 3) with at least one ignition electrode (8) and the ignition electrode (8) being connected to the ignition voltage output (6) of the ignition circuit (5).

Abstract: A circuit arrangement for limiting the current at make for a transformer wherein, in order to avoid the current peak at make when switching a transformer on, resistors are connected between operating voltage and the primary winding of the transformer. A test winding at the secondary side of the transformer is connected via a rectifier to the supply input of a contactor, so that the switches of the contactor close after the transformer is turned on and the resistors therefore no longer lie between operating voltage of the primary winding. PTC-resistors connected in series with the resistors assure that the resistors are not overloaded by the high-operating current of the transformer if the switches do not switch.

Abstract: For protection against electrostatic discharge in electronic apparatuses, a circuit or a component having a connected signal conductor and a discharge conductor connected thereto, is provided with a pointed free end facing and spaced from a pointed free end of a feed conductor together forming a spark gap between the discharge conductor and the feed conductor. Each of the feed conductor and the discharge conductor is arranged with several points forming multiple spark gaps between them.

Abstract: A grounding arrangement for a normally ungrounded multi-phase powerline system, which also carries dc information signals. A resistance and a spark gap device are provided in a path between system neutral and a ground. Upon the occurrence of a predetermined fault condition the spark gap device will conduct, and if the voltage developed across the resistance is of a predetermined value, a current bypass path is established around the spark gap device after a predetermined time delay.

Abstract: As a reserve series gap for a gas-filled three-electrode diverter, an arrangement is used that consists of two disk-shaped electrodes arranged axially behind one another with the same outer diameter and of an insulating foil arranged between these electrodes, these three parts being held together by means of a shrink tube. When such a reserve series gap is associated with an end electrode of a three-electrode diverter, the reserve series gap can also serve as a movable contact element of an overload path, given an appropriate design of the foot of the end electrode and the outer-lying electrode and upon combination with a fusible pellet.

Abstract: A gas-filled surge voltage protector with a high current-carrying capacity. The protector has electrode contacts implemented as strip clamps which in the areas of the end electrodes also surround contact rings that are placed on the base part of the end electrodes. The strip clamps are made of tin-plated sheet metal. One end of the metal strip is designed as a contact element.

Abstract: An overvoltage protection device connected between an AC plug and an electronic device, comprises a first AC pattern having first and second concave circular arc sections and a first peak point, a second AC pattern having third and fourth concave circular arc sections and a second peak point, and a frame ground pattern having a fifth concave circular arc section with the first peak point as a center and a sixth concave circular arc section with the second peak point as a center, both ends of the fifth concave circular arc section being located at centers of the first and second concave circular arc sections, and both ends of the sixth concave circular arc section being located at centers of the third and fourth concave circular arc sections. If an overvoltage is applied to any of the first and second AC patterns, a discharge occurs across any of the AC pattern and the frame ground pattern, allowing the overvoltage to escape to ground.

Abstract: A traveling-wave tube protection circuit prevents faults in its associated power source from damaging it. The power source supplied DC voltages to the collector, slow-wave circuit, anode and cathode of the traveling-wave tube. A power source control circuit is provided between the anode electrode and the anode power source circuit and is used for applying a control voltage to the anode electrode. The control voltage stops the operation of the traveling-wave tube during the transient times which occur responsive to the initiation and the termination of the power source circuit operations. On shutdown, the power source control circuit also stops the supply of the control voltage to the anode electrode after the transient response is terminated. The power source control circuit has a high-frequency oscillator driven in response to either the initiation or the termination of the operation of the power supply means.

Abstract: A circuit for protecting an AC driven load that is controlled by a solid state device, such as a triac, or inverse SCR's, or the like. Whenever the AC power output of the control is asymmetrical to the load, the circuit produces a signal capable of shutting down the AC power to the load, sounding an alarm, switching to a different controller, or signaling another load protecting reaction. The protection circuit continuously measures each individual half cycle of the AC output from the controller to the load and provides for phase shifting about a reference point, resulting in summing (or nulling) of the AC output half waves (positive and negative) at the reference point. The summing (or nulling) reference point is coupled to the gate of a switching element connected across the AC input line, the switching element being responsive to a positive or negative voltage above a predetermined threshold value.

Abstract: To prevent excessive voltages from interfering with a switching transistor supplying a fluorescent tube circuit with alternating pulses from a d-c supply upon removal of the fluorescent tube from the tube transformer, a voltage detector is connected to the primary or input winding of the fluorescent tube transformer to determine occurrence of excessive voltages upon removal of the tube from the secondary, the sensed excessive voltage being applied to a switching circuit to remove the transformer from the supply. The system is particularly applicable to emergency supply connections in which the tubes are, normally, supplied from an alternating current network and from a transistor inverter and a battery under conditions of network power failures.

Abstract: Spark gap apparatuses are provided at the receiving end or the sending end of an electric power substation, in order to protect electric apparatus in the electric power substation against the surge voltage incoming from the power transmission lines. In the case where the gap of such a spark gas apparatus is placed in electronegative gas, for example SF.sub.6 gas, the spark voltage vs. spark time characteristic varies depending on the polarity of the surge voltage and thus the protecting performance of the spark gap apparatus is poor. The improvement in the protecting performance of the spark gap apparatus is provided by substantially equilizing the maximum electric field developed between the end surfaces of a pair of electrodes which are oppositely disposed to each other to form a spark gap therebetween.