This circuit is from a 1968 documentation. It generates a non-symmetrical signal with the waveform shown next to the diagram. Transistors are of the time, but modern equivalents can be used.
Found in a 1966 General Electric documentation, this dimmer should only be used with incandescent...
Using components from the 70s, this circuit can be implemented with modern equivalent components....
This traditional oscillator uses two complementary transistors to produce low frequency signals....