| 摘要 |
PURPOSE:To make it possible to accurately judge the condition of combustion, by computing the ratio of flame electric current and electric power voltage impressed on a flame rod sensor by means of an operational element so that the condition of combustion can be judged by said ratio. CONSTITUTION:Conditions of combustion are detected by detecting ionization current of flame by means of a flame rod sensor 9 inserted into burning flame, while voltage is applied between electrodes 10 and 11 of a sensor 9 by means of an electric power circuit 12. And, electric current passing through the sensor 9 is detected by a flame electric-current detecting circuit 17, whereas in a combustion judging element 28 the condition of combustion of flame is judged by the output of the circuit 17. Furthermore, the flame electric-current detecting circuit 17 is composed of a standard voltage element 19 producing output in proportion to the voltage impressed on the sensor 9 from the circuit 12, an electric-current measuring element 18 producing output in response to electric current passing through the sensor 9, and an operational element 20 producing output, computing the ratio of those values of output as stated above. As a result, output of the circuit 17 is equivalent to the value of ratio of flame electric- current and impressed voltage, so that the combustion judging element 28 can accurately judge the condition of combustion. |
