Active audio filter (CB21770E)

This circuit was found in a 1977 documentation for radio amateurs. Integrated circuits are common operational amplifiers.

Symmetric Power Supply (CB16761E)
This power supply was originally created for the CB16760E (Loudness System) but can be used in any...
Unidirectional motion sensor (CB7281E)
Found in 1980s Electronic Engineering, this circuit uses common phototransistors as sensors. The...
Simple Symmetrical 6 V Power Supply (CB20207E)
This simple, unregulated power supply with an approximate 6 V output voltage can supply currents up to...