| 摘要 |
PURPOSE:To terminate combustion in case of disconnection of a discharging pipe and prevent an erroneous sensing of a flame sensing and a sensing of disconnected discharging pipe by a method wherein a power supply for use in detecting a disconnected discharging pipe is provided, the discharging pipe and a comparison discriminating circuit and a photo-coupler are connected to each other and a microcomputer for use in controlling combustion is connected to the photo-coupler. CONSTITUTION:A microcomputer 32 for use in controlling combustion having a flame sensing means 35 connected thereto is provided. Another power supply 1 for use in detecting a disconnected discharging pipe 23 is provided under an electrical insulated state against a power supply for the microcomputer 32. A discharging pipe 23, a comparison and discriminating circuit 37 for use in discriminating whether an electrical current is flowed in the discharging pipe 23 or not and a primary side 30-a of a photo-coupler for sending a signal from the comparing and discriminating circuit 37 to the microcomputer 32 are connected to the power supply 1. The microcomputer 32 for terminating combustion when a signal having no electrical current in the discharging pipe 23 is received is connected to a secondary side 30-b of the photocoupler. The comparing and discriminating circuit 37 and the photo-coupler 30 may detect an electrical current of the discharging pipe 23, send a signal to the microcomputer 32. The microcomputer 32 may discriminate that if the electrical current flows, the discharging pipe 23 is normally fixed and in turn if the electrical current does not flow, it is judged that the discharging pipe is disconnected and then the combustion is terminated. |
