Method and circuit for balance control of positive and negative ions from electrical A.C. air ionizers

摘要

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. Adjustable means are also provided for varying the by-pass resistance to compensate for changes in positive and negative ion flow that are caused by environmental factors and contamination.