Basic characteristics of self‐control corona discharge air ionizer

We propose a self-controlling corona discharge air ionizer for the static neutralization of electronic products in manufacturing processes. This air ionizer automatically generates only the quantity of ions required to neutralize a charged product, without the need for a control system. This is possible as the device generates ions based on the combination of the electric field of the ionizer emitter, to which a threshold voltage is applied, and the electric field of the product. In this study, the required threshold voltage values were determined by assessing the relationship between the neutralization current and the emitter voltage. The neutralization speed and the final product voltage after neutralization obtained from the ionizer operating on AC voltage were investigated using a charged-plate monitor. The time span required to reduce the charge on a metal plate with a capacitance of 20 pF from 1000 to 100 V was found to be less than 1.0 s, indicating that this device has practical applications. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.