Flame monitoring apparatus
US3936648A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1974 |
| Grant date | Feb 3, 1976 |
| Priority date | — |
| Expiry date | Mar 18, 1994 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF23N5/082
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A filter having a cut-off frequency of the order of 50Hz is included in the circuit of flame monitoring apparatus to remove signals below the cut-off frequency. In the circuit shown, a silicon p-n junction photo-electric pick-up is capacitively connected to an amplifier, the amplifier is connected to a high-pass filter, the output of the filter is connected to a further amplifier, the output of the further amplifier is applied to a detector integrator, the output of the detector integrator is connected to a Schmitt trigger, and the output of the trigger is applied to an output circuit giving a warning signal if the flame being monitored is extinguished. The use of sighting tubes for the photo-electric pick-ups is disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.