摘要 |
A control apparatus for a gas-fired heating appliance having a burner is provided for sensing burner flame instability. The apparatus includes a sensor for sensing a flame and providing an output of a flame current signal, and a controller in communication with the sensor for sensing flame current. The controller is configured to receive the flame current signal and to detect the occurrence of a flame instability condition. The controller detects flame instability from flame current signal data that is measured and Fourier transformed into a frequency spectrum which changes from a stable to instable spectrum when flame instability is caused by an inadequate air-to-fuel ratio. The controller is configured to respond to flame instability by generating an output signal to increase the speed of a combustion air blower that supplies air to the burner, to thereby increase the air flow relative to fuel flow until normal combustion is attained. |