3-way control (CB7047E)

This is a simple circuit to control a set of lamps from 3 different points. We found it in an old Popular Electronics.

LM3900 Buffer (CB14186E)
We found the configuration below, with unit gain, in the National Semiconductor Linear...
Proportional temperature controller (CB21277E)
This circuit is from an Electronic Design from the 90's. The main integrated circuit is uncommon...
Active Low Pass Filter (CB20091E)
This circuit appears on this site from different sources. This is from documentation from the...