| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas warm air heater capable of executing a stable ignition operation even when a tenuous gas left in a gas hose is supplied to a burner by continuously operating an ignition means until thermoelectromotive force reaches a threshold value larger than one used in determining ignition. SOLUTION: A control circuit 21 is so structured as to continuously operate the ignition means 9 until a detection value of a flame sensor comprising a thermocouple 10 reaches a threshold value Vb2 exceeding a threshold value Vb1 for determining ignition even after the detection value reaches the threshold value Vb1, and the ignition state is recognized in an ignition operation. Even when gas concentration transiently lowers and the flame goes out after the ignition is determined with a tenuous gas, the ignition means 9 continuously works until the thermoelectromotive force reaches the threshold value Vb2 and is stabilized after the ignition determination, so that a gas having proper concentration is supplied in that period, and the burner can be ignited again. COPYRIGHT: (C)2004,JPO
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