Using 3 ports, this rectangular oscillator was found in the March 1996 issue of Electronics Now magazine. The maximum frequency is a few megahertz, determined by R1 and C1.
This circuit can be used as a rhythmic light or as a control shield for incandescent lamps from...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
Settings like this can be found in this section and on this website, but from different sources of...