This circuit is from a 1967 publication. The configuration holds true for modern transistors having a feedback across R2.
This useful circuit for the car was found in Radio Electronics magazine from October 1968. It is...
In the figure we have the way to use a 4017 as a sequencer controlled by a microcontroller. With...
This circuit is from a 1992 documentation, but the components used can still be easily assembled. The...