Abstract: A negative ion generator is provide with a plurality of needle assemblies, each of which has a distinct needle end point. The generator includes a drive circuit for providing high voltages to the needle end points and a selection circuit by which the amount of and/or the frequency at which the ions are produced. The needle assemblies are replaceable by the user by way of plug and socket style connections. An indicating means is provided for indicating to the user of the generator the condition of the needle assemblies and when the needles should be replaced. The drive circuit can include a safety current route in the event of an earth fault.

Abstract: The device disclosed herein relates to an apparatus for obtaining energy from an electric field. The apparatus has a floating electrode connected to a series gap device. The floating electrode is adapted to convert the energy found in an electric field into usable electric energy. The usable electric energy can be stored in an electric storage device.

Abstract: This invention relates to an impulse generator which utilizes the properties of floating electrodes. An exemplary impulse generator comprises a floating electrode with a corona source, a series gap, an output terminal for connecting to a device undergoing electric impulse testing and a ground connection. The present invention generates an electric impulse signal for use in testing the impulse response or static electricity impulse response of an electronic circuit.

Abstract: An apparatus for generating negative ions includes two casings which are coupled each other and respectively have an outer thread on one end thereof, a lid which is fastened to the coupled casings, an electrode rod disposed within the coupled casings, an electrode plate disposed within the coupled casings, a circuit board which is disposed within the combined casings and connected to the electrode rod and the electrode plate and having at least one high voltage discharging plate, a high voltage generator which is connected to the circuit board and the high voltage discharging plate, and a plurality of ventilation slots which are respectively defined in the casings and the lid, such that the apparatus can be easily assembled, installed and utilized as an independent unit.

Abstract: The invention relates to a generator of ions in gaseous medium comprising at least one emissive needle (Ag) disposed in a system of plates (P.sub.2, P.sub.4, P.sub.

Abstract: An apparatus and method for producing positive and negative ions and/or electrons in a gas of any atmosphere without producing dust, a method and structure for neutralizing a charged body in a short period of time and for completely preventing static electricity from being generated, and various apparatuses and structures, such as a conveyor, wet bench, and clean room, which use the neutralizing method and structure. The gaseous ion producing apparatus produces positive and negative ions and/or electrons in a gas by irradiating, with electromagnetic waves in a soft X-ray region, the gas under a high pressure, atmospheric pressure, or reduced pressure. In the neutralizing structure an X-ray unit is arranged at an appropriate place to apply the electromagnetic waves in a soft X-ray region to the atmospheric gas surrounding a charged body.

Abstract: A lightning protection apparatus having a tower which is grounded to the earth, an electronic device mounted onto an area adjacent a top of the tower, and a negative ion production device electrically connected to the area of the top of the tower. The negative ion production device serves to produce solely negative ions around and over the electronic device. An auger rod engages the earth so as to be conductively connected to the earth, and an electrical line serves to connect the auger rod to the tower. A shield member is connected to the tower and extends over the electronic device. The negative ion production device is connected to the shield member so as to pass negative ions through the shield member. The negative ion production device can be one or more batteries that are connected together and having a negative terminal connected to the tower and a positive terminal connected to the electronic device.

Abstract: The present invention releases anion out of a main body of an end product, driven by convection caused by heat from heating parts inside the main body. According to this apparatus, anions are released out of the main body by circulating convective air flow caused by heat from heating parts at the lowest part inside the main body. Thus an extra fan and the related circuits are unnecessary.

Abstract: A neutralizing apparatus is provided to facilitate and efficiently implement electric charge removal from a charged body such as a wafer which is easily charged. When the easily charged body such as a wafer is transported in a housing, a neutralizing charge generator, typically light sources for projecting exciting ultraviolet rays into the housing, are operated. Accordingly, the housing is filled with ions and a gas such as non-reactive gas. The neutralizing charge generator can generate positive or negative ions and electrons. When the charged body is positively charged, the electrons or negative ions move toward the charged body to neutralize the charged body with positive charge. When the charged body is negatively charged, positive ions move toward the charged body to neutralize the negative charge.

Abstract: An electrification removing component comprising:a ceramics for removing electrification of which surface resistivity is in a range of 2.times.10.sup.6 through 10.sup.10 .OMEGA./cm.sup.2 ; and an electric conductive material connected to the ground; said ceramics for removing electrification being electrically connected to the electric conductive material with an area by contact or bonding on surfaces of the ceramics for removing electrification and the electric conductive material.

Abstract: A high voltage gap discharge switch is provided with a pair of sphere electrodes 1, projections 2 and a blower 5. The sphere electrodes 1 are separated by a discharge gap and oppose each other. The projections 2 are provided integrally at the mutually facing tips of the sphere electrodes 1, and have a projection length of 1/100 to 1/8 times the diameter of the sphere electrodes 1 and an outer diameter of 1/100 to 1/10 times. The blower 5 gives rise to an air current for expelling products produced on the projections 2 due to the generation of a spark discharge. The blower 5 supplies air to the discharge gap at a wind speed of 0.5 to 25 m/sec.-KW. One objective of the present invention is to stabilize the wave-form of a high voltage pulse and to increase its durability using a simple construction.

Abstract: The present invention releases anions out of a main body, by using convection occurring due to heat from heat elements inside a product. According to this invention, an apparatus for generating anions is positioned at the upper part in a main body, an ascending air stream formed by heat from heat elements which are in the lower part of a product pushes anions out of a product. Thus an extra fan and fan driver are unnecessary.

Abstract: The invention releases anions out of a main body using convection caused by heat from heating elements inside a product without a fan or a blower. To make up for reduction of the amount of released anions due to elimination of the fan, the apparatus according to the present invention can be drawn out from a main body so as to maximize the amount of released anions.

Abstract: Sootless ionizers are provided which greatly reduce the accumulation of ugly black soot on and about the ionizers and adjacent walls or ceiling in the room in which the air is being purified. To this end, the dependable improved ionizers are specially arranged to provide air channels which direct the flow of air past the needles or other ion emitters so that the ions are dispersed through the room for enhanced air purification and the ionized particles are prevented (blown away) from being collected in the ionizers. In one embodiment, the improved ionizers include a plug-in ionizer (PI-1) with an upwardly converging air channel, a curved deflector, and upper and lower sets of air channeling ribs to direct the flow of air past the ion emitters and way from the ionizers. In a second embodiment, the improved ionizer comprises a plug-in ionizer (PI-2) which is similar to the first plug-in ionizer (PI-1) except that it has a single elongated set of air channeling ribs and a motor driven fan to increase air flow.

Abstract: A device for humidifying and ionizing air includes a first chamber for humidifying the air, a second chamber, which is separate from the first chamber, for ionizing the air, and means for aspirating and expelling the air through the two chambers, keeping the streams of ionized air and of water vapor separate.

Abstract: Ionization systems in and for laundry dryers and other contexts, whereby to neutralize static electricity build-up and acidic conditions, and thereby create environmentally friendly systems for drying clothes and other fabrics, generally prolonging fabric life, reducing particle and lint entrainment, and also reducing if not eliminating acidic conditions in dryers and other environs.

Abstract: A self-cleaning, anti-fouling, ionizing air gun for static neutralization and particle blow-off comprises a generally tubular barrel having an open forward or nozzle end and a rearward open end for drawing air therethrough from the atmosphere. A pointed ion emitting electrode is positioned intermediate the ends of the barrel and directs ions toward the forward nozzle end while a plurality of circumferentially spaced air jets direct streams of compressed air in a conical pattern toward the apex thereof in front of the ion emitting electrode so as to induce air drawn in from the open rear end over the electrode to effect cleansing thereof thereby expelling a high velocity ionized air stream through the forward nozzle end.

Abstract: A bar-shaped device for generating electrical charges by corona discharges comprises a high voltage cable surrounded by an insulating casing, extending parallel to the longitudinal axis of the device and adapted to be connected to a high voltage source, a plurality of needle electrodes connected to high voltage via the high voltage cable and arranged in at least one row along the longitudinal axis of the device, an insulating member accommodating the high voltage cable and the needle electrodes and an outer sheath surrounding the insulating member and having a longitudinal slot, wherein the needle electrodes penetrate the longitudinal slot and the edges of the longitudinal slot form counterelectrodes for the needle electrodes. The outer sheath consists of plastic and has grooves at the edges of its longitudinal slot parallel to the row of needle electrodes. A metal stranded wire provided with a casing made of pliable plastic is inserted into each of these grooves as counterelectrode.

Abstract: A system of precipitating dust includes providing a screen arrangement either in the form of a ceiling with walls or in the form of a canopy with the screen being penetrable by air. Inside the screen and particularly adjacent edges of the screen or the canopy there are provided negative ion emitters positioned in rows so as to generate a curtain of ions precipitating the dust from the air onto the ground for collection. Within the screen can be defined either a clean zone or the screen can be used to confine a dust producing process so as to precipitate the dust immediately adjacent the process to prevent it spreading to other areas. Emitters are provided in the form of a carbon fiber yarn which projects outwardly through openings in a channel member with the yarn being doubled back upon itself in some cases to provide a highly directional emission.

Abstract: An ionizer having a pair of electrodes for generating ions by corona discharge when a pulsed DC voltage is applied thereto, wherein each electrode is covered with a microporous glass tube. Release of fine particles is thereby substantially eliminated, the generation of ions not being decreased.

Abstract: Apparatus for conveying a stream of air in a fanned out distribution pattern over a work surface without use of diverting vanes comprises a duct having an inlet end coupled to the discharge of a tangential blower and an open outlet end for delivering a predetermined volume of air therethrough. The shape of the duct gently flares outwardly from the inlet to the outlet to provide a wider but flattened configuration in the direction of the air path although the cross-sectional areas of the inlet and outlet ends of the duct are substantially equal, whereby air exiting from the duct covers a broader yet extended range. Incorporating an A.C. static eliminator in the duct adjacent the outlet yields a uniform field of air ionization.

Abstract: A radon decay product remover for use in a conventional, residential lamp. The remover screws into the light bulb socket of a lamp and provides a replacement socket for a light bulb. The flow of electric current to the light bulb is controlled by an on-off switch in the radon decay product remover. When used in a table lamp, an ion generator includes electrodes (from which negative and/or positive ions are emitted) that attach to the exterior of the lamp shade.

Abstract: An improved discharge wire for use in an electrostatic precipitator which is used for collecting pollutant particles contained in a flow of exhaust gas. The improved discharge wire is a chain having a plurality of chain links made of conductive material. There is provided at least one needle-like member made of conductive material on at least one of the chain links. As an electric potential is applied to the chain, the needle-like member emits corona current. The corona current charges the pollutant particles such that the pollutant particles are forced by the electric field to a collecting member.

Abstract: A surface cleaning apparatus and method is disclosed for disbonding, removal and collection of undesired matter from product surfaces, particularly in controlled process environments. The apparatus includes a negatively chargeable staging surface for receipt thereat of a product having a surface or surfaces to be cleaned, a gas stream nozzle having an electron generation source, usually a negative ion source, adjacent to its outlet, and a positive electrostatic field generator having a collector surface spaced from the staging surface. The electrostatic field generator may optionally include pulse generating circuitry for generating pulsations of selected frequency within the positive electrostatic field. Controls are provided for selectively controlling negative charge at the staging surface, ion output, field strength and, when provided, field pulsation frequency.

Abstract: A self-balancing ionizing circuit for electrical static eliminators having high voltage (pointed) discharge electrodes employs an insulative duct spaced peripherally thereabout. The duct has at least an open exit end with a non-conductive protective grille at the duct terminus in longitudinally spaced disposition from said electrodes. One side of an ungrounded secondary coil of an A.C. high voltage transformer is directly or resistively connected electrically to the discharge electrodes while the other side of the transformer secondary is electrically coupled to an ungrounded conductive band supported within the insulative duct adjacently spaced from the discharge electrodes to define a floating reference electrode with respect thereto. The electric field for ionization is produced between the discharge electrodes and the reference electrode.

Abstract: A system for precipitating dust includes providing a screen arrangement either in the form of a ceiling with walls or in the form of a canopy with the screen being penetrable by air. Inside the screen and particularly adjacent edges of the screen or the canopy there are provided negative ion emitters positioned in rows so as to generate a curtain of ions precipitating the dust from the air onto the ground for collection. Within the screen can be defined either a clean zone or the screen can be used to confine a dust producing process so as to precipitate the dust immediately adjacent the process to prevent it spreading to other areas. Emitters are provided in the form of a carbon fiber yarn which projects outwardly through openings in a channel member with the yarn being doubled back upon itself in some cases to provide a highly directional emission.

Abstract: This invention provides a means for restoring the output waveform of a DC capacitive tip clearance sensor 26 which has been effected by electrical noise in an ion rich environment such as for example a gas turbine engine turbine section 16. The means comprises a pair of electrodes 28,30 each of which is polarized to either a high positive or a high negative potential. The probes 28,30 are situated upstream of the sensor 26 and act to remove any charge carriers from the gas stream before the gas reaches the sensor 26. The sensor 26 may then operate without experiencing undesirable fluctuations in its voltage output.

Abstract: An apparatus for sterilizing and deodorizing rooms comprises a circuit part and an ionization part. High voltage of up to 3 kV necessary for forming corona discharges is produced in the circuit part. The ionization part comprises electrodes, which are arranged on both sides of an insulator plate. An electron emission is produced on the second in operation, which leads to negative oxygen ions, which destroy bacteria and spores and remove odors from the air.

Abstract: An air ionizing cell has an elongated, hollow dielectic cylindrical body member, one end of which defines a greatly restricted orifice (relative to the inside diameter of the cylindrical body member). An elongated metallic electrode having an end tapered at a constant rate and terminating at a microscopically sharp point is disposed coaxially within the cylindrical body member. The point of the electrode is positioned concentrically within the orifice and an electrical potential is applied to the electrode without defining a corresponding ground within the cylindrical body member.

Abstract: A clean non-hydrogen-containing dry gas flows through the corona points of a clean room corona air ionizer in order to suppress the generation of particles.

Abstract: An arrangement for transporting air with the aid of so-called electric ion wind with an air flow duct (1) in which a corona electrode (K) and a target electrode (M) are arranged in mutually axial spaced relationship, with the target electrode located downstream of the corona electrode. The corona electrode and the target electrode are each connected to a respective terminal of a d.c. voltage source (3), the voltage of which is such as to engender an air-ion generating corona discharge at the corona electrode.

Abstract: A portable personal air ionizer includes a dielectric housing small and lightweight enough to be hand carried. The housing contains a circuit for deriving a negative voltage having sufficient value to ionize air molecules, electrodes having pointed ends connected to the high voltage and a ground plane electrode. The negative ions collect airborne particulates which fall by gravity to a collecting pad beneath a stand for fully supporting the housing. Three electrodes are on each of two sheet metal strips, each having an elongated base mounted on a dielectric board. Each electrode is formed as a triangle extending upwardly from the base. The housing includes a central region having an interior wall spaced from an exterior wall. The interior wall forms a well where the circuit is located, surrounded and held in place by a potting compound. An edge of the dielectric board abuts against a dielectric wall between the ground plane electrode and the pointed electrodes.

Abstract: Air ionizing apparatus that produces both positive and negative ions has a housing with air inlet and outlet passages, a plurality of spaced apart air ionizing electrodes and a high voltage supply which applies positive and negative voltages to separate electrodes. A fan creates an airflow that carries the ions out of the housing, the fan preferably being between the electrodes and the outlet passages to promote intermixing of positive and negative ions. The high voltage region of the high voltage supply is isolated from any direct current path to ground. The electrodes then inherently acquire a D.C. voltage bias, when necessary, that maintains an equal output of positive and negative ions without requiring use of an air ion sensor and feedback circuit for the purpose.

Abstract: An apparatus for removing static electricity from charged articles existing in a clean space, particularly in a clean room for the production of semiconductor devices, includes an AC ionizer having a plurality of needle-like emitters disposed in a flow of clean air. A discharge end of each emitter is coated with a dielectric ceramic material. Opposite conductors are also included which are respectively positiond apart from each emitter by a predetermined distance. A DC voltage (or voltages) is applied to the opposite conductors. By adjusting the DC voltage (or voltages), the positive and negative ion concentration generated by each emitter is controlled. Further, a bias voltage may be added to the DC to increase the ion concentration.

Abstract: An apparatus and method for selective environmental conditioning of a substantially enclosed utilization area is disclosed for removal of undesired matter therefrom while more readily establishing predetermined naturally occurring environmental characteristics therein. The apparatus includes negative ion generators and positive electrostatic field generators positioned relative to each other so that the field generators are adjacent to, and spaced a preselected distance from, the ion generators to enhance more even distribution of the positive electrostatic field and negative ions within the enclosed area and particularly adjacent to units and structural surfaces, such as walls, work surfaces, people, equipment, and the like in the area.

Abstract: An apparatus and method for establishing selected environmental characteristics in a substantially enclosed area is disclosed for removal of undesired matter therefrom while establishing selected predetermined desired environmental characteristics therein. The apparatus includes structure establishing the substantially enclosed area, the structure having units for negative ion production and positive electrostatic field establishment positioned therein. The electrostatic field establishing unit includes a field collector and pulse generating circuitry for pulsating the positive electrostatic field at a selected frequency, the field collector preferably having a collector surface which is removable and subject to processing to enable analysis of matter collected thereat.

Abstract: An arrangement for transporting air, with the aid of an ion-wind, includes a corona electrode (K) at least one target electrode (M) located at a distance from the corona electrode, and a d.c. voltage source (4) connected between the corona electrode and target electrode. The arrangement includes a housing (1, 5) with an inlet opening (2) in which the corona electrode (K) is disposed centrally, and an air-flow path extending from the inlet opening and containing the target electrode (M). The target electrode is located spaced form and symmetrical with the center line through the inlet opening. The housing is configured so that the air-flow path downstream of the inlet opening (2) and the corona electrode (K) branches outwardly towards the target electrode (M), thereby forcing air entering through the inlelt opening (2) out towards the target electrode (M) and preventing at least the major part of this air-flow from continuing straight forwards along the extension of the center line.

Abstract: An air conditioner has a negative ion-filtering device in union for purifying function which comprises a PC board to produce negative ions, a high voltage lead, high voltage electric sheets, and a dust mesh, being positioned behind air blow direction adjusting grill of the air conditioner's front upper face. In use after the temperature adjustment is made, the electric sheets which produce negative ions make the passing dust particles of the air carry negative charges and be sucked attached to the dust mesh producing positive ions, this way achieving purification of the air passing therethrough.

Abstract: A self-balancing circuit for convection air ionizers with a passively balanced ion emitter and collector including a circuit in which the ion emitter and the collector are capacitively isolated from external charge sources or sinks for maintaining balance in the positive and negative charge for producing a zero average current flow and a charge balanced ionized airstream.

Abstract: An improved apparatus for generating a negative charge effect in the environment, in which opposite charged spaced electrically conductive plates are dielectric material. A relatively high alternating voltage is applied between alternate spaced plates with sufficient dielectric strength and dielectric constant to withstand the generation of a cold glow discharge or plasma, and withstand the deposit of dirt on them, and withstand exposure to corrosion, humidity, high temperatures, corrosive gases and fumes. A process is disclosed for the separation of undesirable gases and particulates in polluted areas or airstreams. The present invention relates to the excitation, dissociation, and breakdown of gases and other pollutants.

Abstract: A gas ionization system for use in an enclosure having an inlet and an outlet. The system includes at least a pair of spaced electrodes, each electrode being formed of a wire screen, and the wire screens being parallel to each other. A stream of gas is passed through the enclosure and between and parallel to the wire screen electrodes. An electrical power source applies positive and negative voltages to the electrodes to generate an electric field between. The wire screen electrodes have discharge points for field emission of electrons. Free electrons are movable between the electrodes in a direction substantially perpendicular to the direction of travel of the gas stream. The intensity of the electric field is sufficiently large to cause substantially all free electrons in the electric field other than those electrons which ionize gas molecules to be retained in the space between the electrodes.

Abstract: An area ionization system which includes a first set of positive emitters and a second set of negative emitters for providing a supply of positive and negative ions to a work area. A control circuit or computerized control system simultaneously provides high voltage to the positive emitters and to the negative emitters. This "steady state DC" system has been found to be superior to previous systems which provide alternating current or pulsed direct current to emitters. The steady, balanced supply of positive and negative ions allows faster charge decay rates within the work area as well as reduced foreign material contamination. The system also distributes power to the emitters throughout the work area via low voltage lines. The low voltage is stepped up in the emitter arrays in order to supply 8-12 kilovolts to the emitters.

Abstract: Ion content of the atmosphere at a particular location is controlled by generating ions during repetitive period that are initiated by timing signals which reoccur at a predetermined rate. An ion sensor produces feedback signals indicative of the ion content of the air and a feedback circuit varies the duration of the recurring periods of ion generation, if necessary, to maintain the ion content within a predetermined range. Positive and negative ions may be generated during alternate ones of the repetitive periods in which case the feedback circuit inversely varies the periods of positive and negative ion generation to maintain the relative proportions of the two types of ion within a predetermined range. The method and apparatus may be used to suppress accumulation of electrostatic charge by objects, such as in a clean room where electronic components are manufactured, or for other purposes requiring control of the ion content of air.

Abstract: A portable ion generator has a housing with a high tension source therein. The high tension source has two output connections of which one is electrically conductively connected to a high voltage needle electrode while the other is electrically conductively connected to a counterelectrode disposed around the needle electrode. So that the housing of the generator can be worn without being obtrusively visible, without adversely affecting operation of the electrodes, the needle electrode and the counterelectrode are carried by a relatively small carrier member and connected to the high tension source by means of flexible electrical conductor elements. The ion generator has a contact element which is at the potential of the counterelectrode and which may be provided on the housing and/or the carrier member.

Abstract: Air quality control systems for rooms or other enclosed spaces relying on generators which supply charges to particles present in the air thereby purifying or otherwise controlling the condition of the air. A source of high voltage is connected to radiating surfaces of various configurations carrying electrostatic charges. A fan or other air circulating device including natural air movement insures adequate contact of the air with the charges generated to thereby achieve the desired quality control. Operating mechanisms provided in the system include voltage varying circuitry to permit adjustment of the generating intensity. A sensor is provided to detect variations in conditions thereby permitting automatic voltage variations. A remote control station is comtemplated where independent environments may be involved and where separate control of these environments is desired.

Abstract: A compact environmental modification apparatus and method are disclosed for selectively supplementing predetermined characteristics of substantially enclosed environments, for example in rooms, and/or vehicles, to thereby more nearly simulate desirable naturally occurring environmental conditions, and to enhance the performance and/or physical and mental well-being of occupants of the enclosed environment. The apparatus preferably includes operator regulated negative ion and electrostatic field generators, as well as an electrostatic field pulsator for establishing, and regulating the frequency of, pulsations in the electrostatic field, and the apparatus may be incorporated with a system for environmental modification which includes filters for filtering of air circulated through the enclosed environment. The apparatus is particularly well adapted for convenient and advantageous location in vehicles, including, but not limited to, ground craft, aircraft, spacecraft, marine craft.

Abstract: In a device for the electroclimatization of the inner space of a motor vehicle, a first high voltage generator is provided whose output voltage is applied to two substantially oppositely disposed windows of the vehicle chassis. These windows act as electrodes which create an electric field in the inner space of the vehicle. An ion generator powered by a second high voltage generator is mounted in a fresh air conduit of the venting device of the vehicle. The ions which are generated by the ion generator are fed together with the fresh air into the interior of the motor vehicle and are carried therein by the electric field. Seats, steering wheel, safety belts and similar objects which are regularly and permanently contacted by the passengers of the vehicle are connected to ground potential.

Abstract: Ion content of the air in a clean room or the like is controlled by generating positive and negative ions during alternating time periods using positive and negative high voltage generators connected to ionizing electrodes. Ion generation periods are followed by off intervals during which the ions disperse away from the electrodes before ions of opposite polarity are generated. In one aspect of the invention, each period of actuation of a high voltage generator of one polarity is followed by a momentary actuation of the high voltage generator of opposite polarity. This produces ions that are attracted to the electrode of the one polarity and then neutralize residual charge on the capacitors of the generator of the one polarity thereby assuring an abrupt termination of ion generation which can otherwise extend into the subsequent off period.

Abstract: A small personal appliance is wholly contained within a unitary housing that is fully supported by its contact blades being plugged into a wall outlet. The housing includes needles for ionizing the ambient atmosphere and a carbon foam pad for collecting the ionized air. A drive circuit generate cyclically recurring pulses having a voltage which is high enough to ionize the air and low enough to preclude a formation of ozone.

Abstract: An air conditioning system has a negative ion-filtering device in union for purifying function which comprises a PC board to produce negative ions, a high voltage lead, high voltage electric sheets, and a dust mesh, being positioned in the air blow direction path of the air conditioner for use after the temperature adjustment is made. Electric sheets which produce negative ions make the passing dust particles of the air carry negative charges and be sucked attached to the dust mesh producing positive ions, this way achieving purification of the air passing there-through.