| 摘要 |
PURPOSE:To enable normal checking of failure in operation of an operational amplifier and to improve safety of a combustion controller, by a method wherein an arbitrary current value is periodically deducted from a flame current detecting means, and a pulse signal is generated. CONSTITUTION:A voltage, equivalent to a flame current A, is generated at opposite ends of a resistor 17 connected between the inversion input and the output of an operation amplifier 16 for amplifying the flame current A. A resistor 21 functions as a current limit resistance produced when the non-inversion input of the operational amplifier 16 is swung to the negative side by a full given voltage by a current deducting means 15. When a flame current is in a given range, a pulse signal is generated from a comparing means 6, and a fuel feeder 7 detects the pulse signal to control a combustion device. A signal level, equivalent to a flame current, and a signal level, deducted by only an arbitrary current value, are alternately generated from a flame current detecting means 14, actuated by a flame rod 1, with the aid of a current deducting means 15. When the parts of the flame current detecting means mechanically fail, no pulse signal is generated. This enables normally checking of failure in operation of the parts. |
