| 摘要 |
PURPOSE:To enhance safety, by a method wherein the amount of combustion air supplied or the amount of fuel supplied is controlled according to a signal from a combustion condition detector, and combustion is stopped when a predetermined differential value mode corresponding to a change in air-fuel ratio is detected. CONSTITUTION:The combustion condition detector 4 is connected with a resistor 18, and a flame current flowing between the detector 4 and a burner 1 is converted into a voltage impressed on the part consisting of a resistor 19 and a capacitor 20. The value thus converted is transmitted to a resistor 22, an analog switch 23 and a capacitor 24 through an operational amplifier 21, and is further inputted to a comparator 26 through an operational amplifier 25 for a voltage follower. The comparator 26 inputs the detected level of combustion condition into a port P2 of a CPU7, with an output from an analog-to-digital converter 17 used as a reference input. The CPU7 is so programmed as to perform control actions of the relationship between the flame current If under a predetermined amount of combustion air and the air-fuel ratio m in addition to the If- m characteristic with the concentration of oxygen in air takn as a parameter, and controls a controller 6 for the supplied amount of a gas through a driving part 28. |
