6 V power supply with power zener (CB21531E)

This circuit provides 6.3V of output from a 9V input. The circuit was found in a Dutch publication from 1966.

Integrated Intercom (CB18688E)
This circuit is based on the HA1311 integrated circuit, common at the time the article was...
Synchronized automatic switch (CB9260E)
This control circuit up to 1 kW was found in a 1967 RCA documentation. The components are from...
Power operational (CB8782E)
Found in a 90s Radio Electrconics, this circuit is an operational one with a power stage using two...