| 摘要 |
PURPOSE:To enable a checking operation to be performed if an incomplete combustion sensing circuit is normally operated or not in advance before a combustion unit is normally operated by a method wherein the incomplete combustion sensing circuit is assembled with an operating element for producing a pseudo-condition which is similar to the case in which a concentration of gas higher than the specified value is sensed. CONSTITUTION:An incomplete combustion sensing circuit 10 is assembled with a checking operation element 30 for producing a pseudo condition similar to the state in which a concentration of gas more than the specified value is sensed with an incomplete combustion sensing element. A normal-opened switch 301 acting as an operating element 30 is connected in parallel with a CO sensor 11 acting as an incomplete combustion sensing element constituting a voltage divider 13. Before the combustion unit is normally operated, the normal-open switch 301 is closed to produce a state in which a pseudo-condition similar to that a concentration of gas more than the specified value with CO sensor 11, i.e. a relative high voltage of a voltage dividing point D of the voltage divider 13 is attained and at this time if a contact point 5a of a latching relay 5 installed in the driving circuit 6 opens, the circuit 10 may judge this device normal and if it closes, it may judge said device a troubled unit. |
