Abstract: Apparatus for measuring corona current in high voltage A.C. ionizers uses an electrical sensor adjacently spaced from at least one of the discharge electrodes and coupled to electronic circuitry for separating capacitive current from the corona current. In one mode, the capacitive current component is measured directly by a first sensor adjacently spaced from one discharge electrode whose corona current flow to such electrode is either obstructed or squelched entirely while a second sensor monitors total current. The signals from the two sensors are electrically subtracted when applied to opposing inputs of a differential amplifier to provide an output signal proportional to just corona current. In a second mode, a measure of corona current is again provided by electrically subtracting from a total current signal input to a differential amplifier a signal equal to the capacitive current component.

Abstract: A balancing system for electrical A.C. air ionizers having at least one discharge electrode adjacently spaced from a proximity ground and connected to the high side of an A.C. high voltage power source includes (a) a capacitor interposed between each electrode and the high voltage source to maintain a bias on each of the electrodes by blocking the D.C. current component across the circuit capacitance between the discharge electrodes and ground, and (b) a by-pass resistor across the circuit capacitance for providing a path to ground to bleed off excess bias so that equal positive and negative ion densities are generated during corona flow, the by-pass resistor having a resistance value which is determined by the parameters of the system's corona characterisitics (including corona onset voltage and average current flow) that will provide a required equilibrium bias for producing the correct ratios of positive and negative ion currents as will balance the ion densities.

Abstract: Static neutralizer for a tape dispenser in which a roll of tape is rotatably supported for drawing off selected lengths in strips comprises first brush means in juxtaposition with a surface of a tape portion radially peeled from the roll, second brush means in juxtaposition with an outer surface of the tape which has just been bared by the tape portion previously peeled from the roll, and a conductive path electrically interconnecting the first and second brush means, whereby any charges developed on the peeled-away portions of the tape are neutralized prior to dispensing. The respective brush means may be made of carbon or stainless steel fibers whose ends can be adjacently spaced from the corresponding charged surface thereby acting as an induction ionizer with respect thereto or in actual contact with such surfaces and defining a passive static eliminator.

Abstract: A method and apparatus for determining ion flow imbalance. High-magnitude positive and negative potential sources, each having a high-magnitude potential output terminal, are provided. Two electrodes are adapted for positioning adjacent the location of ions, the electrodes having areas for exposure to the ions. A supply of operating potential is provided for the high-magnitude potential sources. The operating potential supply is switched to supply operating potential alternately between the high-magnitude potential sources. Neutral terminals are provided on each of the high-magnitude potential sources and the current flows from the neutral terminals of the high-magnitude potential sources to reference potential are sensed to determine the current flows to the electrodes.

Abstract: In combination with electrical ionizing devices (A.C. static neutralizers or D.C. charging systems) in which discharge electrodes, such as emitter points, are connected to a high voltage power supply and in adjacently spaced disposition behind a grounded foraminous grille, wiper means, such as brushes, for cleaning accumulations of particulate material electrostatically adhered to the electrodes themselves. The brushes are preferrably mounted upon the grille and have bristles passing through slots therein to enable the operator before ionization is instituted to sweep the brushes from an out-of-the-way position relative to the emerging ion flow across the electrodes to effect the cleaning and then clear of said electrodes.

Abstract: An instrument for non-contact measurement of electrostatic fields and related parameters, such as electrostatic potential, voltage and charge density of a charged object, includes a sensor for sensing the electrostatic field produced by the object and for producing an electrical signal, a display for producing a visual readout related to the electrical signal and a range scaling circuit for coupling the sensor to the display. The range scaling circuit is coupled to logic which switches the range scaling circuit and the display back and forth between two ranges, one for relatively higher strength field measurements and one for relatively lower strength field measurements. Because the distance at which the instrument is held from the charged object to achieve an accurate reading depends upon the strength of the field, the range scaling circuit is also coupled to circuitry which indicates the appropriate distance from the charged object at which the instrument must be held to provide an accurate measurement.

Abstract: Ionizing gas gun for ultra-clean static neutralization comprises a plastic nozzle enclosing positive and negative ion discharge electrodes and means for blowing a gas, such as air or nitrogen therethrough. A trigger actuates both the release of gas and application of positive and negative high voltage to the respective discharge electrodes, including delay circuitry for suspending discontinuance of the positive high voltage to its electrode for a momentary period subsequent to discontinuance of the negative high voltage when the gas is cut off in compensation of a slight preponderance of negative ion emission otherwise effected at cut-off. Venturi ports at the nozzle tip draw air over the discharge electrodes for admixing with higher mobility nitrogen ions when nitrogen rather than air is employed as the blowing medium. A changeable filter insures cleanliness, including monitoring means to indicate clogged or ruptured filter conditions or improper installation.

Abstract: A monitor for sensing any break in electrical continuity between a body and earth when the body is coupled to earth by way of a grounding tether used to prevent build-up of static charges on such body. The monitor includes an oscillator circuit for generating A.C. output voltages which are adapted to actuate an alarm. Body capacitance and resistance are coupled by way of the tether across an impedance network either in the tuned circuit determining oscillator frequency or in the output load thereof whereby the resistance or inductance of the impedance network provides the path to ground for the body through its tether. With body capacitance and resistance components of the total impedance, variable elements in the impedance network are adjusted to diminish the circuit output voltage below the threshold voltage required to actuate the alarm when continuity exists while developing an output voltage level sufficient to actuate the alarm when a break in continuity occurs.

Abstract: A panoramic electrostatic field sensor includes a central monitoring electrode for detecting an electrostatic field oriented about a 360.degree. arc peripheral thereto. An apertured housing is concentrically arranged about the monitoring electrode, the housing having circumferentially spaced windows through which the central electrode can "see" any electrostatic field radially disposed with respect to the sensor. A cylindrical shielding cap is rotated in the annular space between the monitoring electrode and the housing, the cap incorporating at least one slot to expose the monitoring electrode periodically to any fields viewed through the housing windows. Electronic means for measuring the voltage in response to the field detected is adapted to activate a static neutralizer for emission of positive and negative ions into the field or to actuate a variety of peripheral indicating or triggering devices which provide signals, alarms or readout functions.

Abstract: A conductive strap for tethering personnel to electrical ground comprises a stretchable band of an elastomeric non-conductive fabric for resiliently embracing a body member in a closed loop. At least one row of a continuous conductive thread is embroidered to the interior surface of the band by a line of stitching which includes a non-conductive thread component penetrating through the fabric from the outside and interlocking with the interior conductive thread component, preferrably sewn in a zig-zag pattern. The conductive thread is coupled to a clasp for electrical connection to ground through a cable tether.

Abstract: A controlled emission static eliminator system (wherein an A.C. high voltage is applied to the discharge electrodes of a static bar by way of a transformer) employs a biasing circuit in series with the primary of the transformer to control the amplitude and/or duration of the alternating potentials imposed on the corona discharge points. The biasing circuit includes a series-connected diode and variable resistance in one leg of a parallel network and a capacitor in the other leg. Selecting appropriate time constants for the resistance and capacitance will narrow the first half of the sine wave and broaden the second half to produce an excess of positive or negative ions, as desired, depending upon the direction of the diode. The ion emission can be controlled to yield an equal number of positive and negative ions or a predominance of ions of one polarity and can be accomplished regardless of whether the A.C. high voltage is directly connected or capacitively coupled to the points.

Abstract: In a shockless type static eliminator having pointed discharge electrodes capacitively coupled to the high voltage side of an A.C. power source and a grounded conductive member or housing adjacently spaced from the discharge points, the improvement comprising the interposing of a high voltage shield about the capacitor plates from which the discharge points project in order to minimize the capacitance between such capacitor plates and ground. The reduced plate-to-ground capacitance, C.sub.g, enables a greater portion of the supply voltage, V.sub.s, to be applied to the discharge points without increasing the discharge electrode-to-high voltage capacitance, C.sub.p, thereby permitting the use of smaller and less expensive power supply and static bar constructions.

Abstract: An extended range static eliminator for impinging a stream of ionized air upon light-sensitive articles to be neutralized includes a housing for directing air through an opening therein toward the articles and a plurality of pointed discharge electrodes supported in the housing across the opening and facing opposite the air stream. The electrodes are preferably capacitively coupled to the high side of an A.C. power source to reduce likelihood of arcing while a conductive casing connected to the other side of the power source partially encircles the discharge electrodes to shield the high voltage field at the base of the electrodes from the ions emitted from the points thereof and further shield the sensitive articles from corona developed around the points.

Abstract: A balanced ion emission system for "shockless type" static eliminators (wherein pointed discharge electrodes are capacitively coupled to one side of an A.C. high voltage source) employs pointed needles which are adjacently spaced from at least some of the pointed discharge electrodes and connected by way of a conductive path to the other side of the A.C. high voltage source. The points of the needles are adapted to be adjustably positioned with respect to the discharge electrodes so that an equal number of ions of each polarity are discharged into the atmosphere for impingement upon the articles to be neutralized.