The circuit shown in the figure below is from the 1993 Linear Technology Applications. The operational ones used are uncommon and the use of equivalents can be analyzed.
Suggested by Mullard in an old documentation, this circuit is based on a common phototransistor and on...
Other series operationals such as the LM258, LM358 and LM2904 can be used on this circuit of the...
This configuration appears elsewhere on this site. This is from a 90’s Popular Electronics and is valid for...