Combustion-state detecting circuit of combustion apparatus

摘要

There is disclosed a combustion-state detecting circuit of a combustion apparatus installed in a combustion chamber, including: a flame detector that has a heat-emitting device for emitting heat on application of an alternating current signal, and produces a potential difference between the current applied to the heat-emitting device and flame-electric current produced by ignition occurring within the combustion chamber; a rectifier that changes the alternating current signal provided by the flame detector into a direct current signal; an inversion amplifier that inverts the direct current signal produced by the rectifier with respect to a reference signal and increases the magnitude of the inverted signal; and a flame discriminator that compares the output signal of the inversion amplifier with a flame discriminating reference signal to determine if ignition occurs.