This circuit was found in a Popular Electronics from the 90's. The operating curve is given next to the diagram. The power transistor must have a heat sink.
This is perhaps the first PIC project to appear in a publication. The article is from Radio...
From a 90s Popular Electronics, this circuit emits pulsating signals for different types of...
This circuit for effects on music synthesizers was found in the May 1983 issue of Radio...