| 摘要 |
PURPOSE:To prevent an erroneous discrimination for the presence of flame by a method wherein an input terminal end of an optical transmitting line is arranged at a place where a light of flame of an electrical discharging igniter is directly reached and an opposite output terminal end is arranged at a position where atmosphere having a specified temperature is placed. CONSTITUTION:An electrical discharging igniter 2 is placed near a pilot flame 1 and an electrical discharging high voltage is supplied from a high voltage generating unit 4 to the electrical discharging igniter 2. A high voltage generator 4 is constructed such that an electrical discharging high voltage is generated at a control signal from a control part 8. The flame 1 is present at an extremity end of a fuel passage 3, and extremity end of a light transmitting line 5 is arranged at a position where the light reaches. An opposite output terminal end of the light transmitting line is set in atmosphere with a temperature less than 150 deg.C. After a light from the flame 1 is changed into an electrical signal by a light sensing element 6, it is changed into a stable electrical signal by a converter circuit 7 and a state of the flame 1 is transmitted to a control part 8 with an electrical signal. Due to this fact, a high frequency electromagnetic field from the electrical discharging igniter is hard to reach an electrical signal for use in discriminating a presence or absence of the flame. |
