Piezoelectric/electrostrictive device and method of manufacturing same

[0002] This application claims benefit of Prov. No. 60/124,231 filed Mar. 12. 1999.

[0003] The invention relates to the field of air ionizers which may be used as static eliminators, and more particularly to a variable length ionizing bar and method of constructing the same, for neutralizing static electricity on moving materials, often in a form of a web or sheets of paper and/or plastic material.

[0004] Ionizing bars are used to generate positive and negative ions which may be used to eliminate built-up electrostatic charges on various items such as paper and/or plastic film products. Typically, when used to eliminate built-up electro-static charges on paper or plastic film products, long webs or sheets of the paper or plastic film product are passed over or under the ionizing bar in order to remove static charges. Due to the variation in width of a wide variety of paper and plastic film products, the width of the running webs and sheets varies from a few inches to several feet. As a result, a wide range of lengths of ionizing bars must be custom manufactured, usually on a short notice.

[0005] Numerous ionizing bar designs and production techniques have been described in the art, including those set forth in the following U.S. patents: D. Koerke U.S. Pat. No. 3,551,743; D. Simons, U.S. Pat. No. 3,585,448; M. Iosue, et al., U.S. Pat. No. 3,652,897; H. Richardson, et al., U.S. Pat. No. 3,875,461; A. Testone, U.S. Pat. No. 3,921,037; A. Testone, U.S. Pat. No. 3,968,405; A. Testone, U.S. Pat. No. 4,031,599; H. Bennecke U.S. Pat. No. 4,048,667; D. Simons, U.S. Pat. No. 4,216,518; A. Testone, U.S. Pat. No. 4,263,636; B. Metz, U.S. Pat. No. 4,271,451; D. Saureman, U.S. Pat. No. 4,498,116 and U.S. Pat. No. 4,502,091; K. Domschat, U.S. Pat. No. 5,034,651 and U.S. Pat. No. 5,057,966; W. Larkin, U.S. Pat. No. 5,501,899.

[0006] Certain known ionizing bars are comprised of a single elongated central high voltage electrode. The high voltage electrode is covered with an insulative or semiconductive sleeve and conductive sleeves. Emitter pins for generating the positive and negative ions extend outward from the electrode. In this type of known ionizing bar. a tubular metallic grounded housing surrounds the high voltage electrode. The metallic grounded housing includes an arrangement of cylindrical openings through which the emitter pins extend from the high voltage electrode.

[0007] Other prior art ionizing bars are comprised of a metal housing in the form of an elongated hollow metallic channel having a longitudinally extended opening. In this type of prior art ionizing bar, a high voltage electrode consisting of cable with an inner conductive core formed by a plurality of stranded wires is contained within the metallic channel of the housing. Emitter pins are formed on the outer layer of the cable by conductive paint.

[0008] Still other known ionizing bars include two or more parallel rows of metal electrodes with sharp emitter pins extending therefrom for generating, positive and negative ions on alternate rows.

[0009] Most of these prior art ionizing bars have a high voltage cable that is integral to the ionizing bar assembly and which is connected to a remotely-mounted high voltage power supply for providing power to the bar assembly. Second, although several of prior art ionizing bars do have connectors for removeably coupling a high voltage power supply to the ionizing bar, each of these connectors are located at only one end of the bar and are only suitable for a cable connection to the bar. Accordingly, a cable is coupled between the connector and the high voltage power supply. Additionally, in all of these prior art designs, the ionizing electrodes are located in a single row (positive and negative emitter pins alternating) or in two parallel rows with positive emitter pins arranged in parallel with negative emitter pins. Finally, in each of these designs all components of the bar, especially the housing, inner cables or bus rods. and insulators arc custom manufactured to a desired length.

[0010] Accordingly, it is would be desirable to provide an ionizing bar design which does not have a cable for connecting a high voltage power supply that is permanently hard-wired to the bar. Such a design should preferably include universal connectors at each end of the ionizing bar for coupling the bar directly to a power supply, or for coupling the ionizing bar to a power supply via a disconnectable extension cable. What is further needed is an ionizing bar design wherein the emitter pins are not arranged in a single row or in two parallel rows but are arranged in a more efficient configuration. What is further needed is a ioinizing bar design wherein multiple ionizing bars can be daisy chained together in order to achieve alternate lengths. Finally, what is needed is an ionizing bar design and a manufacturing method with would allow to pre-assemble a long ionizing bar assembly that will be ready to be cut to a customer-specified length and quickly shipped to the customer, rather that having to be custom assembled to a desired length.

[0011] The objective of this invention is to provide an ionizing bar that is, a) more reliable in operation, b) more economical and easy to manufacture, c) easy to connect to a high voltage power supply directly or via an extension cable, and d) a method of fabrication that provides shorter lead time to deliver bars to the customers.

[0012] In accordance with the present invention, an ionizing bar assembly is comprised of a plastic housing and two individual ionizing electrode modules disposed on opposite sides of the housing. The first ionizing electrode module receives voltage of a positive polarity when coupled to a source of high voltage power, thereby generating ions of a positive polarity. The second ionizing electrode module receives voltage of a negative polarity when coupled to the source of high voltage power, thereby generating ions of a negative polarity. The ionizing electrode modules each include a plurality of printed circuit boards having signal traces thereon with ionizing electrodes or pins extending therefrom. The plurality of printed circuit boards are electrically coupled together by conductive rods or tubing which are preferably positioned adjacent to the traces on the boards and soldered at various positions along the traces. The ionizing electrode modules on each side of the housing are placed at opposing angles and are offset laterally from each other in such a way that the ionizing electrodes or pins extending from one side are located between the ionizing electrodes or pins extending from the opposite side, with the tips of each aligned along a common central linear axis.

[0013] Each ionizing bar assembly preferably slides into two end blocks, which are each located at opposite ends of the bar assembly. The end blocks each include a recess having two pins therein and two socket connectors coupled to the pins at 90 degree angles and extending through a base in each of the two end blocks. The opposite ends of each of the pins extend horizontally through a back end of the end block. The pins are designed to engage with the conductive rods or tubing when the ionizing bar assembly is placed into the recess of the end blocks. The sockets are designed to removeably couple to a high voltage power source. The opposite ends of each of the pins may terminate or may be used for coupling to dual cabling for linking multiple ionizing bar assemblies together. Multiple ionizing bar assemblies may be daisy chained together such that a total length of any desired bar length may be achieved by adding or removing tonizing bar assemblies. The end blocks not only allow the length of any desired ionizing bar to be varied for use in different systems: but, the end blocks further allow assemblies to be easily coupled or removed from a high voltage power source because the high voltage power source is not hard wired to the ionizing bar assemblies.

[0014] FIG. 1 shows a side sectional view of the ionizing bar assembly according to present invention.

[0015] FIG. 2 shows an end sectional view of the ionizing bar sub-assembly according to present invention.

[0016] FIGS. 3A and 3B show side views of a printed circuit board electrode module assembly.

[0017] FIG. 4 is a diagram that shows possible locations where the ionizing bar sub-assembly can be cut into shorter sections.

[0018] FIG. 5A shows an isometric view of an end block used in a preferred embodiment of the ionizing bar assembly of the present invention.

[0019] FIG. 5B shows a cross-sectional side view of an end block used in a preferred embodiment of the present invention.

[0020] FIGS. 6A and 6B show isometric views of a preferred embodiment of a cable plug.

[0021] FIG. 7 shows a side view of a double-ended pin assembly.

[0022] FIG. 8 shows the preferred embodiment for using a double-ended pin assembly to engage an end block of the ionizing bar assembly and a cable plug coupled to a high voltage power supply.

[0023] FIGS. 9A, 9B, and 9C each show various interconnecting combinations of a power supply and ionizing bars according to the present invention.

[0024] In one preferred embodiment of the present invention, an ionizing bar assembly comprised of a plastic housing and two individual ionizing electrode modules disposed on opposite sides of the housing. The first ionizing electrode module receives voltage of a positive polarity when coupled to a source of high voltage power. thereby generating ions of a positive polarity. The second ionizing electrode module receives voltage of a negative polarity when coupled to the source of high voltage power, thereby generating ions of a negative polarity. The ionizing electrode modules each include a plurality of printed circuit boards having signal traces thereon with ionizing electrodes or pins extending therefrom. The plurality of printed circuit boards are electrically coupled together by conductive rods or tubing which are preferably positioned adjacent to the traces on the boards and soldered at various positions along the traces. The ionizing electrode modules on each side of the housing are placed at opposing angles and are offset laterally from each other in such a way that the ionizing electrodes or pins extending from one side are located between the ionizing electrodes or pins extending from the opposite side, with the tips of each substantially aligned along a common central linear axis.

[0025] Each ionizing bar assembly preferably slides into two end blocks, which are each located at opposite ends of the bar assembly. The end blocks each include a recess having two pins therein and two socket connectors coupled to the pins at 90 degree angles and extending through a base in each of the two end blocks. The opposite ends of each of the pins extend horizontally through a back end of the end block. The pins are designed to engage with the conductive rods or tubing when the ionizing bar assembly is placed into the recess of the end blocks. The sockets are designed to removeably couple to a high voltage power source. The opposite ends of each of the pins may terminate or may be used for coupling to dual cabling for linking multiple ionizing bar assemblies together. Multiple ionizing bar assemblies may be coupled together to achieve a total length of any desired bar length simply by adding or removing ionizing bar assemblies in a daisy-chain type configuration. The end blocks not only allow the length of any desired ionizing bar to be varied for use in different systems; but, the end blocks further allow assemblies to be easily coupled or removed from a high voltage power source because the high voltage power source is not hard wired to the ionizing bar assemblies.

[0026] FIG. 1 shows a side sectional view of an ionizing bar assembly in accordance with one preferred embodiment of the present invention. As shown. the ionizing bar assembly 1 includes an elongated rigid dielectric housing 11 which is preferably fabricated of plastic or any other electrically insulating material using any well known extrusion process. The ionizing bar assembly 1 further includes two identical ionizing electrode modules 13aand 13bwhich are located on opposite sides of the dielectric housing 11, and two identical end blocks 15aand 15b,located at opposite ends of the dieletric housing 11.

[0027] FIG. 2 shows a cross-sectional view of the ionizing bar assembly in accordance with one preferred embodiment of the present invention. As shown, the dielectric housing 11 has two symmetrical slots 22aand 22bwhich extend along the length of the dielectric housing 11. The symmetrical slots 22aand 22bare separated by an insulating barrier 23 located between them which also extends along the length of the dielectric housing 11. The symmetrical slots 22aand 22breceive two high voltage ionizing electrode modules 13aand 13bwhich are inserted securely into the symmetrical slots 22aand 22band extend along the entire length of each slot. Each high voltage ionizing electrode module 13aand 13bincludes a printed circuit board (PCB) component 23aand 23band ionizing electrodes 25 extending therefrom. Components 23aand 23bare absolutely identical and are specified under two numbers for convenience only. It is understood that a single PCB component 23aor 23bhas several ionizing electrodes 25 extending therefrom at regular intervals along the length of the PCB component 23aand 23b.

[0028] The ionizing electrodes 25 are in the form of tapered pins which are electrically coupled to PCB components 23aand 23b—i.e. the ionizing electrodes 25 are preferably soldered to the PCB components 23aand 23balong the length of the module at equal and regular intervals. The sharp ends of the ionizing electrodes 25 protrude through the narrow slots 22aand 22bthat extend along the length of the dielectric housing 11. The ionizing electrode modules 13aand 13bare positioned at opposing angles toward each other and are offset from each other laterally in such a way that the ionizing electrodes 25 of one module 13aon a first side of the ionizing bar assembly 1 are located between the electrodes 25 of the opposing module 13bon the opposite side of the ionizing bar assembly 1, with the tips of each of the opposing electrodes 25 substantially aligned along a common linear axis running parallel to the ionizing bar assembly 1.

[0029] Preferably, the electrodes 25 are arranged at an angle facing each other so that the tips of the ionizing electrodes 25 are substantially aligned along the common linear axis which extends parallel to the center of the housing 11. Positioning the ionizing electrodes at an angle preferrably ranging from 30° to 120° toward each other and substantially aligning their tips along a straight central axis has several advantages over conventional electrode designs in which the electrodes are arranged in a row along the same plane. First, this arrangement helps maximize electrical field intensity between emitter pins of two electrodes of opposite polarity in order to improve ionization efficiency. Second. this arrangement also physically separates positive and negative electrode modules, increasing clearance and creepage distances between the conductors of opposite polarities and thus improving the reliability of the device.

[0030] The dielectric housing 11 and the high voltage ionizing electrode modules 13aand 13bcan be made as long as necessary and practical. For example, the dielectric housing 11 can be extruded as long as tens of feet and longer, and then cut to a manageable length of 10-12 feet. Furthermore, even though it is possible to fabricate long strips of the PCB components 23aand 23b,it is not very practical. Accordingly, the PCB components 23aand 23bof the high voltage ionizing electrode modules 13aand 13bwill be manufactured in smaller lengths, such as 12″ or so, and multiple PCB components are then linked together, as will be further described later herein. In another embodiment of this invention, high-value high-voltage rated resistors are connected in series with the ionizing electrodes 25. The purpose of these resistors is to limit short-circuit current from the electrodes for safety, as well as to help stabilize corona discharge at the ionizing electrodes 25.

[0031] FIG. 3A shows a side view of a PCB component 23awith ionizing electrodes extending therefrom in accordance with a preferred embodiment of the present invention. FIG. 3B shows a close-up view of the PCB component 23ain order to illustrate how a single PCB component and ionizing electrodes 25 extending therefrom are coupled. Referring now to FIG. 3A, the PCB component 23acomprises a two-sided printed circuit board strip 33. Surface mount resistors 41 and electrodes 25 are mounted on one side of the printed circuit board strip 33. A bus trace 35 is located on the opposite side of the circuit board strip 33.

[0032] Referring now to FIG. 3B, the first side of the printed circuit board strip 33 is shown. with a cut out showing the bus trace 35 located on the opposite side of the board strip 33. As shown several smaller traces 37 are included on the first side of the board strip 33 and are positioned perpendicular to the bus trace 35 and extending from the bus trace 35. These smaller traces 37 are positioned at equal and regular intervals that can range from ½″ to 4″ apart from each other along the bus trace 35 depending upon the required density of ionization along the length of the bar. The smaller traces 37 are coupled to the bus trace 35 on the opposite side of the board strip 33 by a plated through hole. The smaller traces 37 electrically coupled the bus trace 35 to first ends 39aof surface-mount resistors 41 which are preferably soldered on the first side of the circuit board strip 33.

[0033] As further shown in FIG. 3B. additional small traces 43 connect opposite ends 39bof the surface mount resistors 41 to individual electrode pads 45. The ionizing electrodes 25 are soldered to these pads on the first side of the board strip 33. In this way, each of the ionizing electrodes 25 is electrically coupled to the bus trace 35 through a surface mount resistor 41. In a preferred embodiment, the ionizing electrodes 25 are made of stainless steel, tungsten, or some other metal. The electrodes 25 are machine tapered to a tip. Alternatively, the tip may be tapered using any electro-chemical etching process known in the art of wafer fabrication. Electro-chemical etching is preferred for tapering the electrodes 25 since this process provides a smoother surface that stabilizes ion current over time and helps lower the rate of emitter point contamination. If the electrodes 25 are made from stainless steel or tungsten, these metals may be difficult to solder to the first side of the board strip 33. In order to overcome this problem, the electrodes 25 can be electro-chemically plated with a nickel or gold layer. The plating of the electrodes 25 makes it possible to solder the electrodes to the electro pads 45 on the first side of the board strip 33. In applications characterized by dusty, chemically-aggressive environment, different plating material may be used for positive or negative electrodes. For example, negative ionizing electrodes may have emitter points plated with nickel, and positive electrodes which are typically more prone to contamination, may have emitter points plated with gold.

[0034] In a preferred embodiment, several PCB components 23 are coupled together in order to form a single high voltage ionizing electrode module 13aand 13b.The PCB components are arranged in a row with the bus traces on each individual PCB component 23 are butt-ended one to another inside the dielectric housing 11. Referring now again to FIG. 2, where a cross-section of the ionizing bar assembly 1 is shown, the dielectric housing 11 has two symmetrical details 27aand 27bwhich extend the length of the housing 11. Conductive rods 29aand 29b,or lengths of copper or brass tubing are disposed inside the details 27aand 27b.These conductive rods 29aand 29bare positioned in close contact with the bus traces 35 on each of the circuit board strips 33 of the PCB components 23aand 23b.Accordingly, multiple PCB components 23aand 23bare electrically coupled to one another by the engagement of the bus traces 35 on each of the circuit board strips 33 with the conductive rods 29aand 29b.In order to ensure reliable coupling of the conductive rods 29aand 29bwith the bus traces 35, the conductive rods 29aand 29bmay be soldered to the bus traces 35 at regular intervals along each of the PCB components 23aand 23b.

[0035] After the high voltage ionizing electrode modules 13aand 13bare securely inserted into the slots 22aand 22bwithin the dielectric housing 11, the outer walls 21 of the housing 11 close over the high voltage ionizing electrode modules 13aand 13b,locking the PCB components 23aand 23binside the housing 11 and narrowing the slots 22aand 22bsubstantially to the diameter of the ionizing electrodes 25 which extend outward from the PCB components 23aand 23b.After the high voltage ionizing electrode modules 13aand 13bare each inserted into their respective slots 22aand 22bthe slots are filled with an insulating sealant (not shown) in order to prevent industrial dirt and residue from entering inside the ionizing bar assembly 1. In a preferred embodiment, room temperature curing adhesive or heat curing or light curing adhesive is used as the insulating sealant.

[0036] It is noted that the ionizing bar assembly 1 may be manufactured in a long standard length of several feet. Once assembled. the ionizing bar assembly 1 can be cut into any desired length. FIG. 4 shows the preferred locations where the ionizing bar assembly 1 can be cut into shorter lengths. The locations where the ionizing, bar subassembly could be conveniently cut are indicated by numerals 48athrough 48i.These locations preferably repeat at increments equal to the distance between neighboring ionizing electrodes in the electrode module on one side of the bar in order to ensure that there will always be an equal number of pairs of positive and negative electrodes. The cuts are made exactly in the center between the neighboring ionizing electrodes on both sides of the ionizing bar assembly 1 at locations where there are no surface mount resistors.

[0037] Referring again to the ionizing bar assembly 1 shown in FIG. 1, after the bar is cut to a desired length assembly of the bar is completed by placing two identical end blocks 15aand 15bon each end of the cut assembly. The end blocks 15aand 15bsafely terminate the bus traces 35 on the high voltage ionizing electrode modules 13aand 13band insulate the ends of the conductive rods 29aand 29b.The end blocks 15aand 15bfurther provide reliable electrical connection of a high voltage power supply to the bus traces 35 of the high voltage ionizing electrode modules 13aand 13bthrough the slotted pin assemblies contained within the end blocks 15aand 15b.Finally, the end blocks 15aand 15bfacilitate the mechanical attachment of the ionizing bar assembly 1 to the production equipment where the bar is to be installed and utilized.

[0038] FIG. 5A shows an isometric view of an end block 51 used in a preferred embodiment of the ionizing bar assembly of the present invention. The end block 51 can be molded out of dielectric polymer materials, such as ABS, PVC, or any other dielectric polymer known in the art. The end block 51 includes a recess 53 in the cross-sectional shape of the dielectric housing 11, such that the ends of the housing slide inside the recess 53 in each of the two end blocks 51. The end block 51 further includes two pin connector assemblies 55 that can be either insert-molded or inserted into a rear side of the end block 51. The pin connector assemblies 55 engage with the conductive rods 29aand 29b(i.e. the slotted pins 56 will fit securely within the copper tubing) when the housing 11 slides into the recess, thereby electrically coupling the pin connector assemblies 55 to the bus traces 35 of the high voltage ionizing electrode modules 13aand 13b.

[0039] FIG. 5B shows a cross sectional side view of an end block 51 used in a preferred embodiment of the ionizing bar assembly of the present invention. As shown, the pin connector assemblies 55 are preferably slotted pins and socket assemblies which include a slotted pin 56 that fits securely into the metal tubing (i.e. the conductive rod 29a) while the socket 59 extends vertically upward through the end block 51 when the end block 51 is secured to the end of the ionizing bar assembly 1. The sockets 59 are accessible via holes or openings molded into the end blocks 51. In a preferred embodiment, the end block 51 is designed in two individual portions, a bar-side portion 60 (where the recess is located) and mount-side portion 62 (where the bar may be coupled to the apparatus or to another bar using cabling, as will be described further hereinafter). The two portions will telescope into each other and be secured together using epoxy or another type of adhesive.

[0040] A source of high voltage can be connected to the ionizing bar assembly 1 directly via the sockets 59 or may be coupled to the ionizing bar assembly 1 via a cable connected between the power supply and the sockets 59 in the end block 51. If cabling is used, the cable will preferably have cable plugs on each end for coupling to the sockets 59. FIG. 6 shows a preferred embodiment of a cable plug 61 with a cable attached to it which may used to couple a high voltage power supply to the ionizing bar assembly. As shown, the cable plug 61 consists of a base 63 and a cover 65 which are formed as two plastic molded parts. In the base, there are two socket connectors 67aand 67binserted into two holes. The sockets in the cable plug 61 are identical to the sockets 59 in the end blocks 51, and the distance between the sockets in both components is identical. The two cables 69aand 69bare cut to the desired length and their ends are stripped of insulation. The center conductor of each cable 69aand 69bis inserted into a through hole 71 formed at the outer end of the corresponding socket and then secured with a set screw 72. The base of the cable plug and the cover are joined together with two self-tapping screws from the base side of the assembly.

[0041] In an alternative embodiment, the socket connecters on the end blocks 51 may be converted into male pins using double-ended pin assemblies. FIG. 7 shows a double-ended pin assembly 73 which may be is used to change the female socket connectors in the end blocks 51 into male pin connectors. A first end 75 of the double-ended pin 73 has a machined groove 77. A second and opposite end 79 of the double-end pin 73 is preferably smooth. A grommet 81 made of an elastic material is securely fastened around the middle portion of the double-end pin 73. In a preferred embodiment, the sockets used in the end blocks 51 are each equipped with a contact, such as #08 contact manufactured by Mill-Max Mfg. Corp., which is press fit inside the barrel of the socket. The machined groove 77 located at the first end 75 of the double-ended pin 73 is formed to slip through the contact when engaged in the sockets in the end block 51. The fingers of the contact will engage into the machined groove 77 and prevent easy removal of the double-ended pin out of the socket in the end block 51. When the grooved end 75 of the double-ended pin 73 is engaged into the socket it may sustain up to a 20 lb force tension without coming loose in order to insure a fail safe connection. The second and opposite end 79 of the double-ended pin 73 has a smooth surface which preferably couples to the cable plug of a high voltage power supply or an extension cable.

[0042] FIG. 8 illustrates double-ended pins 73 engaged between an end block 51 of an ionizing bar and a cable plug 61 coupled to a high voltage power supply for supplying power to the ionizing bar assembly 1. As shown, the end block 51 has two sockets 59. and the cable plug 61 also has two sockets 67. The double-end pins 73 are inserted into the end block 51 of the ionizing bar with the grooved ends 75 inside. The fingers of the contact 83 allow the grooved end 75 to pass through. However, the double-ended pins 73 are securely held in place by the fingers of the contact 83 which engage into the groove 77 and prevent extraction of the pin. Therefore, the end block of the bar becomes a male connector in the illustrated configuration. The socket 67 of the cable plug 63 accepts the smooth end 79 of the double-end pin 73. The extraction force of the pin inserted with its smooth end is low, and upon separation of the cable plug from the end block 51 of the ionizing bar assembly 1 the double ended pins 73 remain locked within the end block 51. In other words, the cable plug will remain a female connector. As a result, the cable plug that attaches the high voltage cables to the ionizing bar will not have any exposed high voltage pins if the cable plug is disconnected from the ionizing bar assembly 1. This provides an additional safety measure and makes it easier and safer to connect/disconnect the ionizing bar from the application system. The grommet 81 that is placed over the middle portion of the double-end pins 73 engages and seals the interface between the end block 51 and the connector plug. In a preferred embodiment, the two parts are mechanically held together with a plastic snap-in fastener 90.

[0043] Referring to FIG. 9, the ionizing bar assembly of the present invention has several advantages. First, a removeable power supply 92 with output sockets can be directly connected to one of the end blocks 93 of the ionizing bar 1a,with double-ended pins coupled between the sockets in the end block 93 and the high voltage power supply 92 in order to safely secure the removeable power supply 92 to the end block 93. The opposite end block 94 may terminate with sockets at the end block 94 without any double-ended pins inserted therein. This configuration is illustrated in FIG. 9a.

[0044] Alternatively, a high voltage power supply 92 with output sockets can be directly connected to one of the end blocks 93 of the ionizing bar 1a,with double-ended pins coupled between the sockets in the end block 93 and the high voltage power supply 92. The second end block 94, located at an opposite end of the ionizing bar 1a,always terminates with connector sockets for safety. A cable plug 95. of an extension cable 96, can be used at the end block 94 in order to couple a second ionizing bar 1bassembly to the first ionizing bar assembly 1a.The cable plug 95 has pins. A cable plug 97 has sockets that would connect to the pins in the end block 98 of the second bar 1b.An extension cable, similar to a bar, always has sockets at the open energized end. An opposite end block 99 in the second ionizing bar assembly 1bterminates with sockets at the end block 99 without any double-ended pins inserted therein. This configuration is illustrated in FIG. 9b.

[0045] Finally, a high voltage power supply 92 with output sockets may be connected to a first cable plug 101 at a first end of a first extension cable 102. The first cable plug 101 has double-end pins inserted into its sockets with the grooved ends inside in order to safely secure the first cable plug 101 to the power supply 92. A second cable plug 103, located at the other opposite end of the first extension cable 102 preferably has output sockets. The second cable plug 103 connects to a first end block 93 of a first ionizing bar 1a,the first end block 93 preferably has double-ended pins inserted into its sockets with the grooved ends inside. The first cable plug 95 of the second extension cable 96 is connected to the second end block 94 of the first ionizing bar 1a,located at the opposite end of the ionizing bar 1a.The second cable plug 97 on the other end of the second extension cable 96 connects to the first end block 98 of the second ionizing bar 1b.The opposite end block 99 of the second ionizing, bar 1bterminates with output sockets. This configuration is illustrated in FIG. 9c.

[0046] From the above description. it will be apparent that the invention disclosed herein provides a novel and advantageous ionizing bar assembly and method of fabricating the same. The foregoing discussion discloses and describes merely exemplary methods and embodiments of the present invention. As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.