This circuit is a Voltage Sensing Window Comparator circuit with an active-low LED indicator. Its primary function is to monitor an input voltage and determine whether it stays within a specific "safe window" defined by an upper and lower voltage threshold. Try adjusting the voltage, at the central potentiometer first. Use the link below to see the pdf.. Page 28
https://www.scribd.com/document/630133784/Engineer-s-Mini-Notebook-Op-Amp-IC-Circuits-Forrest-M-Mims-III-pdf
