This nice analog indicator circuit was found in the January 1974 issue of Radio Electronics magazine. The circuit has 8 scales with individual adjustments. The instrument is rated at 50 uA.
This photometer is based on a Wheatstone bridge that must be balanced by the linear potentiometer P1. The...
Utilizing the MAX4172 or MAX495 integrated circuit, this circuit increases the sensitivity of a...
The article that teaches the assembly is from a Radio Electronics issue from July 1969. The...