This circuit only works with incandescent lamps and the frequency is adjusted in the pot, depending also on the capacitor. The triac must be equipped with a heat sink. The circuit is from an 80s manual.
Found in an old Popular Electronics this circuit is still current. The SCR can be of the 106...
This circuit simulates the signal produced by a muscle, serving to adjust medical equipment. The circuit...
Pressing S1 by a moment L1 glows up, remaining by a time interval depending on C1. This time...