04757422 is referenced by 50 patents and cites 14 patents.

A dynamically balanced ion generator is provided which incorporates a detection screen and feedback loop to ensure that the number of positive and negative ions emitted from the generator are substantially equal. The detection screen is located between the ion generating electrodes and the exit port of the device, and is contructed of conductive material which captures a predetermined percentage of ions emitted by the electrodes. The detected imbalance is corrected through a feedback loop comprising an operational amplifier circuit, a low pass filter, a balance control comparator, variable duty cycle oscillator. By varying the duty cycle of the variable duty cycle oscillator, the voltage applied to the primary of a high voltage transformer is controlled such that the relative concentrations of positive and negative ions generated may be altered to compensate for any detected imbalance.

Title
Dynamically balanced ionization blower
Application Number
6/906907
Publication Number
4757422
Application Date
September 15, 1986
Publication Date
July 12, 1988
Inventor
Michael R Betker
Holland
PA, US
Robert H Dunphy Jr
Holland
PA, US
Peter R Bossard
Langhorne
PA, US
Agent
Nixon & Vanderhye
Assignee
Voyager Technologies
PA, US
IPC
H05F 3/04
View Original Source