Audio amplifier 741 (CB20478E)

This low power audio amplifier was found at 1992s Popular Electronics. Transistors are general purpose common types.

Simple 555 Timer (CB3982E)
This configuration is suggested by Mullard (Philips) in an old manual of 555 integrated circuits....
Air Pressure Change Sensor (CB6528E)
Found on Popular Electronics in the 1980s, this circuit detects a change in air pressure using a...
30 and 50 V power supply (CB8678E)
This source was originally suggested by Delco in a 1969 documentation to power amplifiers up to 50 W. The...