LM3900 Amplifier (CB25165E)

This circuit with Norton operation is from an article in Radio Electronics magazine. The gain is given by the resistors.

Random Lights (CB18725E)
This circuit can be used as a rhythmic light or as a control shield for incandescent lamps from...
Audio Line Amplifier (CB4769E)
We found this circuit in a European publication from the 1990s. Transistors are still common types...
Bilateral current source (CB20359E)
Settings like this can be found in this section and on this website, but from different sources of...