DEVICE FOR SELECTIVE CHECK OF FLAME OF BURNER IN COMBUSTION CHAMBER OF COMBUSTION UNIT Russian patent published in 1998 - IPC

FIELD: automatic control of presence of flame in combustion chamber of combustion unit; power and industrial steam generators and other plants burning various kinds of fuel. SUBSTANCE: device includes optical filter 1, photoelectric sensor 2, light radiation generator 3 with light-emitting diode 4, electric circuit 5 for processing total valid optical signal furnished to sensor 2 through optical filter 1 from burner flame and light- emitting diode 4 and control unit made in form of threshold device 6. Electric circuit 5 includes amplifier 7 for amplifying electric signal furnished from sensor 2, high-frequency filter 8, amplitude detector 9, adjustable amplifier 10 of sensitivity of sensor 2 and ripple filter 11. Connected to output of adjustable amplifier 10 is additional electric circuit 12 for developing signal of self-diagnosis from light radiation generator 3 including band-pass filter 13 tuned to above-mentioned signal. EFFECT: enhanced reliability through improved detuning caused by false signals and availability of effective self-check of optical signal processing circuit. 2 cl, 1 dwg