Method and apparatus for regulating air ionization
US4951172A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1988 |
| Grant date | Aug 21, 1990 |
| Priority date | — |
| Expiry date | Jul 20, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T23/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Ion content of the atmosphere at a particular location is controlled by generating ions during repetitive period that are initiated by timing signals which reoccur at a predetermined rate. An ion sensor produces feedback signals indicative of the ion content of the air and a feedback circuit varies the duration of the recurring periods of ion generation, if necessary, to maintain the ion content within a predetermined range. Positive and negative ions may be generated during alternate ones of the repetitive periods in which case the feedback circuit inversely varies the periods of positive and negative ion generation to maintain the relative proportions of the two types of ion within a predetermined range. The method and apparatus may be used to suppress accumulation of electrostatic charge by objects, such as in a clean room where electronic components are manufactured, or for other purposes requiring control of the ion content of air.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.