| 摘要 |
A safety circuit 31 , which compulsorily closes an on-off valve for supplying a gas to a burner when a microcomputer for performing a combustion control is in an abnormal condition, does not operate unless abnormality occurs to the microcomputer 1 , and therefore even when the safety circuit 31 is out of order, an ignition operation is performed as it is. A transistor 4 is not turned off until a fixed time elapses from a start of an ignition sequence in the safety circuit 31 , but the fixed time is shortened by a timer acceleration circuit 32 , and if the transistor 4 is turned off by a transistor 2 being turned on, the safety circuit 31 is determined as normal, so that the normal ignition sequence is executed thereafter.
|
