This 1000: 1 voltage-controlled filter circuit was found in an Electronics Today International in a 1980s edition. The circuit is based on components of the time.
In this circuit of a 1968 publication the unijunction may be 2N2646 and the transistor BC548. The...
The purpose of this circuit is to improve a trigger circuit using a zener diode. The circuit was...
This interesting circuit of the American publication Electronics Handbook Volume XIII 1993 shows a...