This circuit is from the time when slide projects were used. We find it in a 90's Wels’ Think Tank. The lead times can be adjusted from 5 to 30 seconds.
This circuit for audio signals was found in the March 1990 Radio Electronics magazine. The circuit...
In the figure we have the way to implement a sinusoidal oscillator with the 4093 IC. The component...
Equivalent transistors, like the BC548 and BC558 pair can be used in this circuit that we find in an...