This is a typical point scale or moving bar circuit with the LM3915. We found it in old American documentation. The operational amplifier supports an equivalent modern type.
September 2016 - Mouser Electgronics already has in stock the new moisture digital sensor HDC1010...
This circuit was found in a Radio Electronics of August 1952. The transistors are germanium types...
We found this Nicad cell charging circuit in an English publication from the 1970s. The circuit can...