Fast-acting spark-over detector
US4644439A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 2, 1984 |
| Grant date | Feb 17, 1987 |
| Priority date | — |
| Expiry date | Nov 2, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/903
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A spark-over detector for an electrostatic precipitator has a current sensor (3) which provides a signal (a) which is differentiated twice to produce a signal (c). If the level of the signal (c) is above a predetermined level then a level-detecting circuit (7) passes a signal (d) to an AND-gate (8). A second level detecting circuit (9) receives the signal (a) and if this signal is above a predetermined level passes the signal (e) to a timing circuit (10) which provides a signal (f) from a first preset time after having received the signal (e) until a second preset time after the signal (e) has ceased. Thus, if a spark over starts to occur signals (d) and (f) occur simultaneously and the AND-gate produces an output signal (g) which can be used to trigger the thyristor switch circuit of the pulse generator to conduction to prevent thyristor damage or destruction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.