Abstract: A novel semiconductor switching device for use in high voltage applications (typically ranging from 5 kV up to about 50 kV) makes use of the well-known effect of reverse conduction in silicon diodes when exposed to light. Hitherto, photodiodes have been commercial available for relatively low voltage applications. The device disclosed herein is implemented by a high voltage diode having a series of semiconductor junctions and a light emitting diode operable to irradiate the junctions to render the high voltage diode conducting in the reverse bias direction. The switching device finds application in electrostatic spraying devices where the current demands are relatively small, eg up to about 2 .mu.A.

Abstract: A miniature air purifier produces a corona discharge surrounding a needle-like emitter point connected to a novel negative 8,000-volt DC power supply. The power supply operates from a nine volt battery and contains a step-up voltage inverter having a single transformer outputting high voltage spikes with a voltage multiplier operating on the output of the inverter. The production of high voltage spikes of about 200 Hz rather than a sinusoidally varying voltage significantly reduces current consumption. The needle-like emitter point is located about 1/4-inch from an 80% open mesh metallic grid held at ground potential. Corona discharge at the emitter point ionizes the air and creates ozone, and nitric oxide both of which combine with direct electron impact decomposition to detoxify and destroy a wide variety of airborne pollutants including pathogens, chemicals and allergens.

Abstract: Removal of electrostatic charges from a body (3), in particular an article of manufacture submitted to electrostatic painting, is achieved by a device comprising an accumulation mass (2) made of lead and coupled with a copper drainage element (4), both having a ribbon-like structure and being rolled up in the form of a coil (5), upon interposition of an insulating layer (6) between the contiguous turns (5a). The drainage element (4) has an input terminal (7) disposed in the middle of the coil (5) and connected with the body (3), and an output terminal (8) disposed on the coil periphery and connected to the conventional grounding line (T).

Abstract: This invention pertains to an AC charger (10) in which an AC voltage waveform applied to a corona wires (12) has a duty cycle of between 50% and 90%. This increases the efficiency of the charger without increasing the signal-to-noise ratio. In one embodiment, the AC voltage waveform is asymmetric.

Abstract: A device and method for stunning a human or other living animal employs a nozzle or other such means through which a conductive fluid stream can be discharged toward the living animal; a current supply that is electrically coupled to the conductive fluid stream; and a grounding conductor that is coupled between the current supply and a ground potential. When the conductive fluid stream is discharged toward the human or other living animal and impacts the human or other living animal, the current supply passes a current through the human or other living animal when the human or other living animal becomes electrically coupled between the conductive fluid stream and the ground potential. The current is of sufficient magnitude to stun the human or other living animal. As a result, the human or other living animal is stunned when impacted with the conductive fluid stream.

Abstract: An apparatus for applying an electrical charge to a charge retentive surface, wherein a bias contact roll member is situated in contact with a surface of the photoreceptor. The bias contact roll member is supplied with an electrical bias including an oscillating voltage signal having a DC offset, wherein the oscillating voltage is clipped via a rectifier circuit to remove a predetermined polarity component thereof.

Abstract: An air-core transformer device for supplying a high-frequency, pulsating DC voltage on the secondary side of the transformer. The primary side of the transformer has two windings which are bifilar-wound having a mutual phase relationship of 180.degree., where the end of the first winding is connected in series with the beginning of the second winding at a common junction point. The voltage supply on the primary side is controlled by a time-set or time-variable power control signal at the beginning of the first winding and at the end of the second winding. A DC voltage is supplied to the common junction point. Two oscillatory circuits are formed on the primary side by a frequency control signal supplied over a field effect transistor, and are maintained by two capacitors C1 and C2, C1 being connected in parallel with the first winding and C2 being connected in parallel with the second primary winding.

Abstract: An improved power supply for an electrostatic spray gun device having a voltage multiplier circuit adjusts to variations in the output load conditions of the multiplier circuit and dynamically modifies the operational loadline of the multiplier circuit in order to maintain optimal operating conditions for the spray gun device notwithstanding output load variations. The power supply utilizes a loadline manipulation circuit coupled to a feedback circuit that monitors the output load, and the manipulation circuit, in response to a feedback signal from the feedback circuit that is proportional to the output load, varies the input voltage level to the multiplier circuit to modify the loadline of the power supply in response to varying load conditions. The manipulator means of the power supply has memory means to store a variety of external commands which will control the manipulation means and a user interface to enter the external commands into the memory.

Abstract: An improved electrostatic precipitator system is provided for use in high-grease atmospheres in which the grease is electrically conductive. The precipitator includes high-voltage insulators that are both located in areas unlikely to accumulate electrically-conductive grease and that, in themselves, can operate in a high-voltage system without tracking, even when a certain amount of conductive grease has accumulated on the insulators' surfaces. In a multi-cell precipitator system, a high-voltage insulator is provided as part of a cell-to-cell assembly that receives high-voltage electricity on one side of its insulator, and conducts that electricity to its opposite side, and is placed in a specially-shaped cut-out in the bulkhead between the cell chambers, in which the cut-out is shaped so as to minimize the amount of grease that may accumulate upon the cell-to-cell assembly's insulators.

Abstract: Electrical apparatus for removing ecologically noxious substances from gases which includes an electrical precipitator having a reaction chamber through which a stream of the gases to be cleaned passes, and which includes an elongated electrode extending into said reaction chamber for producing a corona discharge within the chamber. The apparatus of the invention includes a multi-stage Fitch generator connected to the electrode which produces a high level pulsating voltage superimposed on a constant direct current voltage. The pulsating voltage causes the electrode to produce the corona effect in the chamber, and the constant direct current voltage sets up an electrostatic field which removes unwanted products of the corona discharge from the gas stream passing through the chamber. The Fitch generator is adapted to provide pulsating voltages of sufficient amplitude and steepness to produce a high density, high energy corona discharge within the chamber.

Abstract: Air purification system where air is subjected to complex electrical field resulting from a DC voltage and AC frequency in kilovolt and kilohertz range respectively, applied to screen assembly in air path. DC amplitude and AC frequency self regulate to selected parameters. Parameters are selectable independently of one another.

Abstract: A small, battery-powered air purifier can be clipped to a wearer's front shirt pocket or worn suspended from a cord about the wearer's neck. The device includes a housing containing a compact circuit that transforms direct current provided by the battery into a negative high voltage pulsating current which is connected to a sharp metal point contained within a chamber inside the hollow housing. A corona discharge forms on the sharp point, ionizing air molecules and any particulates, and generating ozone. An opening into the chamber is covered by a noncorrosive metal grid connected to the positive terminal of the battery. The negative ions are attracted to this grid, thereby completing an electrical circuit. Movement of the ions to the grid results in mass movement of air which causes a stream of air to emerge through the grid. As the air passes the grid, negatively charged particulates are deposited on the grid.

Abstract: Method and apparatus for releasing a workpiece, such as a semiconductor wafer, from an electrostatic chuck. A "dechucking" voltage is applied to the chuck electrode having the same polarity as was used to retain the workpiece, but having a different magnitude selected to minimize the electrostatic attractive force between the workpiece and the chuck. There is an optimum value for the dechucking voltage which minimizes this force. The optimum value can be determined empirically, or it can be determined by a method based on the value of the current pulse produced when the workpiece is first mounted on the chuck.

Abstract: An image forming apparatus comprising a body to be charged, and a central processing unit for processing based on oscillation clock pulses from a crystal oscillator, including a timer for generating a pulse signal having a predetermined period based on the oscillation clock pulses. A charging member performs a charging operation on the body to be charged, and first applying means applies a first AC voltage to the charging member, wherein the first applying means generates the first AC voltage based on a pulse signal from the timer in the central processing unit.

Abstract: A pulse train generating circuit for accurately controlling the ozone production of an ozone generator, is disclosed. The ozone generator may be an electrode type ozone generator or a laser type ozone generator. The circuit generates a first signal indicative of the target rate of ozone production. A control signal of a predetermined length first time period having enable and disable portions is then generated. The temporal sum of the enable portions in each separate time period of the control signal is representative of the target rate of ozone production. A train of pulses corresponding to the enable portions of the control signal is passed by a pulse train gate, and is fed to the ozone generator so as to cause generation of ozone. The amount of ozone generated during the first time period is directly related to the temporal sum of the pulses in the train of pulses, so as to thereby provide accurate control of the amount of ozone being generated.

Abstract: Three electrodes are disposed at lateral sides of a plasma generating chamber of an etching apparatus serving as a plasma generating apparatus. A sample stage is disposed at a lower part of the plasma generating chamber, and an opposite electrode is disposed at an upper part thereof. High frequency electric power having a first frequency is supplied to the sample stage and the opposite electrode. Respectively supplied to the three electrodes 4, 5, 6 are high frequency electric powers which are oscillated by a three-phase magnetron, which have a second frequency different from the first frequency and of which respective phases are successively different by about 120.degree. from one another, thus forming a rotational electric field in the plasma generating chamber.

Abstract: On the inner surface of a chamber are circumferentially disposed three lateral electrodes at regular intervals. To the lateral electrodes are applied three high-frequency electric powers of 50 MHz, each differing in phase by approximately 120.degree.. On the bottom of the chamber is placed a sample stage serving as a second electrode, around which is provided a ring-shaped earth electrode. To the sample stage is applied high-frequency electric power of 13.56 MHz. The distance between each of the three lateral electrodes and the earth electrode is longer than the distance between the sample stage and the earth electrode.

Abstract: Air purification system where air is subjected to complex electrical field resulting from a DC voltage and AC frequency in kilovolt and kilohertz range respectively, applied to screen assembly in air path. DC amplitude and AC frequency self regulate to selected parameters. Parameters are selectable independently of one another.

Abstract: An image forming apparatus having both an image data carrying member for carrying and forwarding image data rendered into a visible image by a developer and a device requiring high voltage in the form of a unit separable from a body of the image forming apparatus, wherein, inside the separable unit are a high voltage generator for the device and an electrically conductive member, the high voltage generator being disposed within the image data carrying member, the electrically conductive member being interposed between the image data carrying member and the high voltage generator and between the device and the high voltage generator, insulating members being interposed between the electrically conductive member and the image data carrying member and between the electrically conductive member and the device, the electrically conductive member being grounded.

Abstract: A charging device for producing a voltage potential on a photoconductive member including a corona generator for charging a portion of the image receptor to a substantially uniform potential; a corona generating potential source electrically connected to the corona generator; a sensor for determining the potential on the image receptor; and a microprocessor including an analog to digital converter interconnected to the corona generating potential source; the sensor; and the controller for regulation of the potential on the image receptor.

Abstract: A contact charge supply device for externally controlling the charges, which are supplied to a member to be charged by bringing a contact member appled with an external voltage into contact with the member to be charged, which at least includes an underlayer, and holds the following inequalitylog (R).gtoreq.log {Rp.times.(Va-Vt)/Vt}+(.alpha.-.beta.).times.log(S/s)+.gamma..times.log (i/I)where .vertline.Va.vertline..gtoreq..vertline.Vt.vertline.,Va (V): voltage applied to a contact member in contact with the member to be charged; I (.mu.A): current flowing from the contact member to the member to be charged; S (cm.sup.2): contact area of the member to be charged and the contact member; R (.OMEGA.): resistance of the contact member when current I (.mu.A) is fed to an area corresponding to the contact area S (cm.sup.2) of the contact member; .gamma.: current dependency of the resistance of the contact member; 1-.beta.: area dependency of the resistance of the contact member; s (cm.sup.

Abstract: An image forming apparatus is provided with a photosensitive member; a charger including a corona ion generator and a grid electrode provided between the photosensitive member and the corona ion generator, and adapted for charging the surface of the photosensitive member while regulating the surface potential of the photosensitive member by the grid electrode; a current supply circuit connected to the charger and capable of supplying to the charger a first current not lower than a specified level for charging the surface of the photosensitive member at a first voltage at which an image of high contrast can be formed and a second current lower than the specified level for charging the surface of the photosensitive member at a second voltage at which an image having an intermediate gradation thereof emphasized is formed, the second voltage being lower than the first voltage; and a current switch circuit for switching the level of the current to be supplied to the charger means according to needs.

Abstract: The present invention relates in particular to electrostatic holding devices for holding semiconductor wafers and other materials during processing operations, such as vacuum sputtering, for example.One problem with such holding devices is that a residual electrostatic charge tends to build up on the surface of the device. This can lead to problems in the release of the wafer when processing is completed, as this electrostatic charge will tend to grip the wafer.The present invention overcomes this problem by determining a value of drive voltage to be applied to the electrostatic chuck to cancel out the holding effects of at least most of the residual electrostatic charge and thus enable release of the wafer. The value of drive voltage to be applied to allow release is determined by monitoring motion of the wafer as the drive voltage is varied, the motion of the wafer being indicative of whether it is being gripped by the body or not.

Abstract: A power amplifier for use in medical and veterinary testing and therapy. A tunable pulse-width-modulated signal generator is connected to a gating element to provide a digital waveform suitable for comprehensive control of the waveform shape and average output power provided by the apparatus. The digital waveform controls a power driver. Through use of a high-Q resonant circuit including a capacitor and a primary winding of a coil assembly, a voltage of about 150-400 volts is increased to about 10 kilovolts at the primary winding. The coil assembly has a secondary:primary turns ratio of 10:1, resulting in a signal of about 100 kilovolts at the output of the secondary winding. This arrangement produces a corona discharge at a discharge pin connected to the secondary winding. A manual tuning embodiment and a self-tuning embodiment are disclosed.

Abstract: An electrostatic clamp or chuck and method uses soft square wave, slew rate limited, A.C. clamping voltages and a balanced, differential drive for clamping flat articles such as semiconductor wafers to pedestals, wafer transfer blades, and the like, with a large ratio of clamping force to clamping voltage, reduced decay of the clamping force and associated nearly constant maximum clamping force, instantaneous elimination of remnant clamping force when the clamping voltage is removed (instant off operation), isolation of the clamped article from the clamping voltage, and substantial elimination of vibration. Preferably the A.C. frequency is 0.1 to 60 Hz. The instant off operation is enhanced by increasing the frequency as the clamping voltage is decreased.

Abstract: A tester applies a high-voltage test signal across the probes of a high-voltage measuring apparatus, wherein at least one of the probes is mounted at a probe end of an elongated insulated pole. The tester includes a battery-powered generator for generating the test signal which is applied across two contact terminals, respectively adapted for connection to the probes. One of the contact terminals is disposed at the bottom of an elongated tubular socket which receives the probe end of the pole, the contact terminal including two conductive members spring-biased apart until the pole is inserted in the socket. The generator is energized through a switch which may be mounted on the generator housing. In one embodiment the other contact terminal is an alligator clip and in a second embodiment the other contact terminal is disposed in a second socket.

Abstract: A scorotron charging device applicable to electrophotographic image forming equipment and having a main charger with discharge wires and a grid and applying voltages to the wires and the grid by respective power sources. The two power sources are controlled by the same control signal. In response to the control signal, a voltage starts being applied to the grid before a voltage is applied to said wires and ends being applied to the grid after the voltage application to the wires has ended. This allows the charge potential of a photoconductive element to rise and fall rapidly.

Abstract: An electrostatic chuck having an electrostatic holding member arranged on an upper surface of the chuck main body for holding a semiconductor device during a plasma etching process. The electrostatic holding member includes a pair of insulating polyimide members and a conductive member interposed between the polyimide members. In operation, a voltage is applied to the first conductive member in order to generate static electricity to be applied to the electrostatic holding member for holding the semiconductor device.

Abstract: An image forming apparatus capable of preventing a toner from depositing on non-charged part of an image carrier just after the start of an image forming operation even when implemented with a contact reversal development system and a contact charging system. A charge power source assigned to a charging roller feeds a current great enough to prevent toner deposition on the non-charged part of the image carrier to a constant voltage generation circuit which is connected to the image carrier.

Abstract: A surface discharge plasma cathode electron beam generating assembly (1) includes an anode (2) maintainable at a substantially constant first potential, a cathode device (3) having a first electrically conductive member (4), a dielectric member (5) at least partially surrounding the first member (4) and electrically conductive means (6) located on the outer surface of the dielectric member (5) and insulated therefrom. A capacitative divider circuit (7) is provided for maintaining the first electrically conductive member (4) at a second potential different from the first potential and for maintaining the electrically conductive means (6) at a high negative third potential relative to the first and second potentials.

Abstract: In an electrostatic paint spray gun having a built-in high-voltage cascade that is cast into an insulator member together with a transformer, a carrier tube is provided that is composed of a tube section and of an annular flange, whereby the electrical component parts of the high-voltage cascade are arranged and fixed at the outside jacket of the tube section and the output resistors are arranged and fixed at the annular flange. The inside bore of the tube carrier can serve as a receptacle for the high-voltage stranded electrode conductor.

Abstract: An image forming apparatus includes a corona charger, a surface electrometer and a memory provided around a photoreceptor drum. When power supply of the image forming apparatus is turned on, an image adjusting process is carried out. In the image adjusting process, level of charging the corona charger is changed stepwise, the surface potential on the photoreceptor drum at the time is measured by the surface electrometer and the result of measurement is stored in the memory. When image forming process is carried out subsequently, the charge level of the corona charger is set based on the data stored in the memory.

Abstract: An arc preventing electrostatic power supply suitable for operating an electrostatic paint atomizer such as a rotary atomizer. High voltage control is based on the high voltage current, as measured in the ground return path. The power supply is controlled to provide a substantially constant high voltage DC output up to a predetermined current and an output voltage which rapidly drops off as the current increases above the predetermined current. The magnitude of an AC component superimposed on the high voltage DC current is detected to determine incipient arcing. Upon detecting an incipient arcing condition, the output voltage is interrupted for a predetermined short time. When the output voltage is turned back on, it is ramped up from a low level back to the normal high voltage level. While the output voltage is less than a predetermined low level, the sensitivity of the incipient arc detection circuit is increased.

Abstract: A self-resonating power supply for controlling operation of an electrostatic air cleaner wherein the ouput voltage to the cell is limited to a desired value by means of a regulated feedback circuit so as to prevent nuisance arcing in the cell and to minimize generation of ozone. The feedback circuit detects changes in the output voltage and responds to such changes by changing the biasing of a switching transistor so as to cause the output voltage to return to the desired value.

Abstract: A first voltage is first applied to the electrode or electrodes of an electrostatic chuck for electrostatically attracting a workpiece such as a silicon wafer. Then, before the workpiece is removed from the electrostatic chuck, a second voltage which is of opposite polarity to the first voltage is applied to the electrostatic chuck for eliminating a residual attractive force from the electrostatic chuck. The second voltage has a voltage value which is 1.5 to 2 times higher than the voltage value of the first voltage. The second voltage is continuously applied for a period of time which is in inverse proportion to the voltage value of the second voltage.

Abstract: A grid electrode voltage control aparatus is for a scorotron charging device having a corona discharge electrode operatively connected to a corona producing power source and disposed opposite a counter electrode, and a grid electrode disposed between the corona discharge electrode and the counter electrode. A shunt-regulated stabilized power supply is operatively connected to the grid electrode and has an output variably responsive to the intensity of current flowing through the grid electrode. A series-regulated stabilized power supply (preferably comprising a dc-dc converter and a current limiter) is operatively connected to the shunt-regulated stabilized power supply.

Abstract: An electrostatic chuck for semiconductor wafers (10) uses at least three electrodes (12, 13, 14). Two electrodes (13, 14) defining a substantially planar surface and embedded in a thin dielectric film (11), are respectively excited by a low-frequency A.C. supply (15, 16, 17, 18, 23) to produce sinewave fields of controlled amplitude and phase, provided a low resultant voltage on the wafer surface. A third electrode (12) acts as a shield electrode or as a reference point for the other two electrodes (13, 14). In addition, by controlled rates of voltage application and removal, low voltage gradients are obtained on the wafer (10); and no retentive forces exist in the dielectric medium (11). A low A.C. amplitude excitation of the chuck enables capacitive current sensing of the relative positions of the wafer (10) and the dielectric film (11), enabling simple control of voltage application to the two electrodes (13, 14).

Abstract: An equal voltage is applied to a corona shielding case and a screen grid, when a normal mode is set, while a switch is changed over to connect the shielding case to ground when a photo mode is set. Therefore, part of a discharge voltage from a corona discharger is grounded in the photo mode. It is therefore possible to make the surface potential of a photosensitive body in the photo mode in which the shielding case is grounded lower than that in the normal mode in which the shielding case of the corona discharger is placed at a potential corresponding to an output direct-current voltage of a high-tension transformer. As a result, half-tones of photographs can be reproduced effectively.

Abstract: An image recording apparatus in which a constant current is supplied from a high voltage source to a charging unit to charge a photo-sensitive material, and the constant current is further supplied to a peeling unit to peel a printing sheet off the photo-sensitive material on which an image has been recorded is provided with a high voltage supply current stabilizing circuit which comprises; a first resistor for stabilizing a constant current supplied to the peeling unit, the first resistor being larger in resistance than the peeling unit; and a second resistor for stabilizing a constant current supplied to the charging unit when the resistance of the first resistor is larger than the resistance of the peeling unit, whereby a constant current is stably supplied to the peeling unit even when the resistance of the latter changes.

Abstract: A system and method for applying charge to a photoconductive surface wherein an electrode is spaced between the surface and a shield including applying a voltage to the electrode such that current therein is the sum of surface charging current and shield current, utilizing the shield current to obtain a signal proportional to the surface charging current and utilizing that signal to control the application of voltage to the electrode. The shield current and the sum of shield current and surface charging current flow in different directions relative to a current summing node and the signal proportional to surface charging current is obtained from the node. That signal is compared to an input control signal to control the application of voltage to the electrode. A high voltage supply has an output, a return input and a control input and variations in a signal applied to the control input cause variations in the output of the supply.

Abstract: A safety circuit arrangement for the high-voltage generator of an electrostatic filter, in particular of an electrostatic soot trap for diesel internal-combustion engines including a grounded filter housing and a filter electrode, has a power supply (15) which is connected to the high voltage generator (20) via controllable switching means (34). A and a shielded high-voltage cable (17), the high-voltage line (18) of which connects an output (24) of the high-voltage generator (20) to the filter electrode (14). To eliminate the risk to people caused by components carrying high voltage, the shield (19) of the high-voltage cable (17) is connected at one end to the filter housing (11), and at the other end to a control device (25) in such a way that an interruption of the shield (19) leads to the generation of a control signal for the switching means.

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: A brush type charging unit having a constant-current regulated power supply for supplying a constant current to a moving photosensitive medium through a conductive brush fiber contacting the moving photosensitive medium for charging the photosensitive medium uniformly such that the charged potential varies within a range smaller than 10 V when an atmospheric condition changes from 5.degree. C.-20% RH to 35.degree. C.-80% RH. The constant-current regulated power supply has a pulse removing circuit for charging the moving photosensitive medium uniformly even when a few pin-holes exist in the photosensitive medium. A fiber element has a resistance between 4.5.times.10.sup.7 ohm and 1.times.10.sup.13 ohm when the fiber element has 1 denier in size and 1 mm in length, for charging the photosensitive medium and avoiding burning of the fiber element.

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 electrophotographic image forming apparatus for forming an image on a recording sheet comprises a photosensitive drum for holding a toner image thereon, in developer for forming the toner image on the photosensitive drum, an image transfer device for electrostatically transferring the toner image from the photosensitive drum to the recording sheet, and a sheet separator for separating the recording sheet from the photosensitive drum as the recording sheet advances. The sheet is controlled to generate a discharge voltage which includes separator at least alternating currents at various duty factors.

Abstract: An electrostatic spray gun having an internal alternator-turbine power supply is provided with an air circuit which divides the air passages to the front end of the gun on one hand and to the power supply in the other hand at the trigger valve to prevent paint or solvent leakage into the power supply. The power supply is completely encapsulated or potted such that the only parts of the power supply extending through the containment are heat sinks, electrical connectors and a voltage indicator. Lastly, as C-clip is provided to attach the turbine alternator to the rest of the power supply which utilizes an interior groove on the alternator turbine and an exterior groove on the main body of the power supply.

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: A system (10) is provided for etching a surface (14). A vacuum enclosure (12) is provided to create a vacuum around containers (13) and the surface to be etched (14). A pressurized gas source (16) is utilized to input gas into the containers (13). A wire coil (38) is wrapped around the containers (13) and provided with an oscillator (40) to generate radio frequency energy. The radio frequency energy excites the gas within the containers (13) which is then discharged through an output opening (46) toward the surface to be etched (14). A vacuum pump (20) is provided to evacuate the enclosure (12).

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 power source device including a lower voltage inverter transformer having plural secondary windings and a higher voltage inverter transformer having a primary winding connected directly to one of the secondary windings of the lower voltage inverter transformer without any rectifying circuit or inverter circuit interposed therebetween. The lower voltage and higher voltage transformers are contained in the same casing, the internal space of which is filled with an electrically insulative material to provide a unit device.