This circuit was found in the August 1996 Electronics Now magazine. The circuit is based on an operational circuit whose type determines the gains and limits for the frequency.
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,...