| 摘要 |
PURPOSE:To enable control of an air-fuel ratio with high precision, by providing a relative value computing part which compute a relative value between an output from a flame current detecting part and an output from a flame current memory part when a combustion amount control part outputs a signal, by means of which a fuel amount is changed by a given difference in a fuel amount is fed, to a fuel feed means. CONSTITUTION:Fuel fed from a fuel tank 2 with the aid of a fuel pump 3 is evaporated and mixed with air, fed by means of a blower 4, by the use of an evaporating mixer 5 to burn the mixture by means of a burner 1. In this case, a combustion amount control part 9 controls driving of a fuel pump 3 so that a fuel amount predetermined according to an air amount is fed. A current flame current If1 is outputted from a flame current detecting part 8 to a flame current memory part 10. The combustion amount control part 9 controls the fuel pump 3 so that an amount of fuel being fed is changed finely. A relative value computing part 11 computes a relative value If2/If1 between a flame current If2, detected by the flame current detecting part 8, and a memory content If1, stored by the flame current memory part 10, and outputs a signal, by means of which an amount of fuel being fed is regulated, to the combustion amount control part 9 so that the computing result is adjusted to a predetermined constant K. |
