We found this circuit in a Motorola documentation from 1968. Phototransistors are common and bipolar general purpose.
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...