PURPOSE: To enable a misfire of a burner to be detected rapidly and accurately by a method wherein a variation rate of decreasing in burner temperature and its temperature after a fuel valve is opened.
CONSTITUTION: It is defected by a temperature sensing block 2 if a burner temperature is less than a predetermined value. AND gate 4 is not opened unless a time elapses more than a specified period of time by an on-delay timer 3B so as to make a misfire sensing signal null. In addition, an output of an on-delay timer 3A and another output of AND gate 4 are given to an OR gate 5. Accordingly, when the variation rate of decreasing of burner temperature is continued for more than a predetermined time in its state more than a specified value, or after a specified time (t1) elapses after a fuel valve is opened and the burner temperature is decreased to a value less than its predetermined value, it is judged that this is a misfire state. With such an arrangement, it is possible to prevent any erroneous operation.
SHIGENO TOSHIO
YOSHIOKA HIDEKI
FUJI ELECTRIC CO LTD
| JPS61165521A | 1986-07-26 | |||
| JPS62118948U | 1987-07-28 | |||
| JPH02219911A | 1990-09-03 |