The present approach relates to generating seed electrons at a spark gap in the absence of .sup.85Kr. The present approach utilizes electron emission from a triple-point instead to provide seed electrons to reduce the statistical time lag of a spark gap. In one such implementation, a spark gap a spark gap may be fabricated and/or operated without a radioactive component without otherwise changing its overall form or function of the spark gap.

The design of the triggering circuit 1 of the overvoltage protection, connected via three poles 4 to the spark gap of the overvoltage protection, provided with the first input terminal 2 and the second main terminal 3, whose principle consists that an auxiliary electrode 7 of the spark gap 4 is connected in series to the first varistor 8 and one end of the secondary winding 14 of the transformer 13, the other end of which is connected to the second main electrode 6 of the spark gap 4 and the second input terminal 3, whereas one end of the primary winding 15 of the transformer 13 is connected in series to the gas discharge tube 10, the second varistor 9, resistor 11 and capacitor 12, connected to the other end of the primary winding 15 of the transformer 13, connected to the second input terminal 3, whereas the junction connecting the second varistor 9 to the resistor 11 is interconnected with the junction, connecting the first input terminal 2 to the first main electrode 5 of the spark gap 4. The advantage of such a design of the triggering circuit 1 of overvoltage protection resides in the thermosensitive disconnector 17 coupled with the thermal coupling 16 to the second varistor 9, is either connected in series to the second varistor 9, or connected to the link of the junction connecting the second varistor 9 to the resistor 11 and the junction connecting the first input terminal 2 to the first main electrode 5 of the spark gap 4, or that the thermosensitive disconnector 17 is connected between the primary winding 15 of the transformer 13 and the gas discharge tube 10.

The design of the triggering circuit 1 of the overvoltage protection, connected via three poles 4 to the spark gap of the overvoltage protection, provided with the first input terminal 2 and the second main terminal 3, whose principle consists that an auxiliary electrode 7 of the spark gap 4 is connected in series to the first varistor 8 and one end of the secondary winding 14 of the transformer 13, the other end of which is connected to the second main electrode 6 of the spark gap 4 and the second input terminal 3, whereas one end of the primary winding 15 of the transformer 13 is connected in series to the gas discharge tube 10, the second varistor 9, resistor 11 and capacitor 12, connected to the other end of the primary winding 15 of the transformer 13, connected to the second input terminal 3, whereas the junction connecting the second varistor 9 to the resistor 11 is interconnected with the junction, connecting the first input terminal 2 to the first main electrode 5 of the spark gap 4. The advantage of such a design of the triggering circuit 1 of overvoltage protection resides in the thermosensitive disconnector 17 coupled with the thermal coupling 16 to the second varistor 9, is either connected in series to the second varistor 9, or connected to the link of the junction connecting the second varistor 9 to the resistor 11 and the junction connecting the first input terminal 2 to the first main electrode 5 of the spark gap 4, or that the thermosensitive disconnector 17 is connected between the primary winding 15 of the transformer 13 and the gas discharge tube 10.

A method for protecting an electrical transmission system having an electrical transmission line coupled to electrical equipment from hazardous EMI comprises receiving at least one pulse of hazardous EMI on the transmission line, and shunting current induced on the electrical transmission line by the at least one pulse of hazardous EMI to ground through at least one static series spark gap apparatus in such manner as to bypass high speed transient voltages from the electrical equipment to ground via a low impedance means and prevent damage thereto, wherein the static series spark gap apparatus has a rise time that is typically 2 nanoseconds or less.

A method for protecting an electrical transmission system having an electrical transmission line coupled to electrical equipment from hazardous EMI comprises receiving at least one pulse of hazardous EMI on the transmission line, and shunting current induced on the electrical transmission line by the at least one pulse of hazardous EMI to ground through at least one static series spark gap apparatus in such manner as to bypass high speed transient voltages from the electrical equipment to ground via a low impedance means and prevent damage thereto, wherein the static series spark gap apparatus has a rise time that is typically 2 nanoseconds or less.

A spark plug is provided which includes a hollow cylindrical center electrode disposed inside a metal shell and a ground electrode joined to the metal shell. The ground electrode has an inner peripheral surface facing an outer peripheral surface of the center electrode. At least one of the outer periphery of the center electrode and the inner periphery of the ground electrode has formed therein at least one recess whose ends lies in a center-to-ground electrode facing region where the outer peripheral surface of the center electrode faces the inner peripheral surface of the ground electrode in a radial direction of the center electrode. This decreases voltage required by the spark plug to achieve discharge.

An electronic apparatus and an overvoltage protection structure thereof are provided. The overvoltage protection structure includes a first signal transmission end and a second signal transmission end. The first signal transmission end has at least one first side, and couples to a protected component through a conductive wire. The second signal transmission end has at least one second side, wherein the at least one second side corresponds to the at least one first side and is adjacent to the at least one first side. Therein, there is at least one gap between the at least one second side and the at least one first side, and the gap is positively related to a threshold voltage of the overvoltage protection structure.

An electronic apparatus and an overvoltage protection structure thereof are provided. The overvoltage protection structure includes a first signal transmission end and a second signal transmission end. The first signal transmission end has at least one first side, and couples to a protected component through a conductive wire. The second signal transmission end has at least one second side, wherein the at least one second side corresponds to the at least one first side and is adjacent to the at least one first side. Therein, there is at least one gap between the at least one second side and the at least one first side, and the gap is positively related to a threshold voltage of the overvoltage protection structure.

A spark plug is provided which includes a hollow cylindrical center electrode disposed inside a metal shell and a ground electrode joined to the metal shell. The ground electrode has an inner peripheral surface facing an outer peripheral surface of the center electrode. At least one of the outer periphery of the center electrode and the inner periphery of the ground electrode has formed therein at least one recess whose ends lies in a center-to-ground electrode facing region where the outer peripheral surface of the center electrode faces the inner peripheral surface of the ground electrode in a radial direction of the center electrode. This decreases voltage required by the spark plug to achieve discharge.

An approach is disclosed for generating seed electrons at a spark gap in the absence of .sup.85Kr. The present approach utilizes the photo-electric effect, using a light source with a specific nominal wave length (or range of wavelengths) at a specific level of emitted flux to generate seed electrons.