Adjustable reference (CB21540E)

We found this circuit with 5.3V zener in a Philips publication from the 60s. The op amp could be a modern equivalent.

Weak Signal Differential Detector (CB6665E)
This circuit was obtained from a 1966 documentation. The transistors are of the time. The circuit...
High Impedance Precision Rectifier (CB5097E)
This precision rectifier circuit is suitable for applications in an AC / DC converter. We find it...
Astable Neon (CB10504E)
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...