Automatic infrared radiation flame monitor - converts photoresistor voltage to operate switching transistor with two stable states

摘要

The infrared radiation flame monitor utilises the intensity fluctuations in the infrared radiation as flame combustion characteristics. The arrangement operates automatically and reliably due to the use of semiconductors for amplification and signal processing. The radiation received by the lead sulphide photoelectric resistors is converted into square wave signals after amplification of the voltage of these resistors. The input signal is fed, after processing, by an impedance converter to a charging capacitor with voltage and time determining circuits. The output voltage is used for a switching transistor so that this transistor is operated only in two stable states.