| 摘要 |
PURPOSE:To make liquid fuel leakage detectable surely with simple constitution by controlling an ignition heater of a petroleum atove or the like and a light source for optical transmission according to the output signal levels of a photoelectric conversion means. CONSTITUTION:When an ignition switch 2 and a transistor 17 go on, electric current flows from an electric power source 1 to an iginition heater 18, and an apparatus using liquid fuel is ignited. An optical fiber 19 is provided between an LED15 and a phototransistor (TR) 5, and an oil leakage detecting part 20 is provided in the midway part of the fiber 19. When oil sticks on the part 20, the output of the TR5 decreases and the output of a voltage comparator 7 decreases, then the outputs Q, Q' of an FF11 go to the low level, and the heater 18 is put out and the LED goes on. |
