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.

Flash trigger (CB23692E)
This is a very common circuit in the days of xenon flashes for cameras. This is from a Radio...
48 V power supply LM340 (CB14263E)
National Semiconductor suggests this circuit in its 1994 Linear Applications Handbook. The D3...
Touch Sensor On Off 4093 (CB15523E)
The difference in the circuit shown in the figure, in relation to the CIR8144r, is that it uses a...