Corona current monitoring apparatus and circuitry for A.C. air ionizers including capacitive current elimination
US5017876A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1989 |
| Grant date | May 21, 1991 |
| Priority date | — |
| Expiry date | Oct 30, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/0061
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus for measuring corona current in high voltage A.C. ionizers uses an electrical sensor adjacently spaced from at least one of the discharge electrodes and coupled to electronic circuitry for separating capacitive current from the corona current. In one mode, the capacitive current component is measured directly by a first sensor adjacently spaced from one discharge electrode whose corona current flow to such electrode is either obstructed or squelched entirely while a second sensor monitors total current. The signals from the two sensors are electrically subtracted when applied to opposing inputs of a differential amplifier to provide an output signal proportional to just corona current. In a second mode, a measure of corona current is again provided by electrically subtracting from a total current signal input to a differential amplifier a signal equal to the capacitive current component. However, while the total current signal in this case is again obtained by a single sensor adjacently spaced with respect to one electrode, the capacitive current signal is generated independently of a sensor through electronic circuitry coupled to the A.C. line voltage. In a third mode, a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.