Found in a 1990s American technical brochure, this circuit is intended for alarms that use as photodiode sensors. The circuit has a frequency response of up to 20 kHz. The gain is 40 dB.
This control panel allows the use of NO and NC sensors, turning the alarm on after 30 seconds...
This LM139, 239, or 339 comparator configuration appears elsewhere in this site and this section....
The frequency of the blinking of this circuit is given by the capacitor that can have its value...