| 摘要 |
PURPOSE:To provide a positive termination of combustion if a discharging pipe is disconnected and then provide a prevention of leakage of discharging gas by a method wherein a pulse generating circuit is connected to the discharging pipe through a switching element, a discharging pipe comparing and discriminating circuit is connected and a signal from the comparing and discriminating circuit is inputted to a microcomputer. CONSTITUTION:A pulse generating circuit 36 is connected to a discharging pipe 23 through switching elements 14 and 16 for applying an electric current to the discharging pipe 23 only when a pulse outputted by the pulse generating circuit 36 is set at a predetermined level. A comparing and discriminating circuit 37 discriminating whether an electric current is lowed in the discharging pipe 23 or not is connected to the discharging pipe 23. An output side of the comparing and discriminating circuit 37 is connected to an input side of the microcomputer 32 for terminating operation in case that an electric current is not flowed in the discharging pipe 23. The pulse generating circuit 36 may flow an electric current to the discharging pipe 23 only when a generated pulse is at a predetermined level of 'H' or 'L'. The comparing and discriminating circuit 37 connected to the discharging pipe and the microcomputer 32 receiving a signal from the comparing and discriminating circuit may receive the signal and if the electrical current flows in the discharging pipe 23, the system judges that the discharging pipe is normal and if the electric current does not flow, it is judged that the discharging pipe is disconnected and then the combustion is terminated. |
