It serves as a reference, since today we can have simpler and more compact solutions. This circuit is from an Electronics Experimenter Handbook from 1992. The integrated circuits are from that time.
This circuit with JFET and Unijunction was found in an ancient American documentation. The...
This metering bridge circuit uses one power supply only. The operational ones depend on the...
We found this configuration in the 1964 RCA transistors manual. As indicator loads in each stage,...