Patent ID: 7177133

Claim:
A method of generating positive and negative ions comprising: generating AC high voltage; providing different polarity of the high-voltage to at least one pair of ionizing electrodes mounted in separate conducting cages located adjacent to each other, each of the cages provided with an opening opposite the electrode; balancing ion currents emitted by each of the electrodes by providing a balancing unit, output from the AC high voltage being provided via the balancing unit to the electrodes, each electrode provided with different polarity; and generating an external electric field by providing electrical potential difference between the cages, wherein the electrical potential difference between the cages, with reference to the ground is provided using the ion current from each electrode across to the cage in which the electrode is mounted, passing through an element for producing a voltage drop, whereby some of the ions generated from the electrodes escape outside the cages due to the presence of external electric field.