Solid state relay (CB8518E)

This circuit was found in a 90s Popular Electronics. Both the coupler and the MOSFET can be of any type.

AD Converter for Current Monitor (CB5246E)
Found in a 2005 Linear Technology application manual, this circuit provides outputs from a current...
High sensitivity photo Darlington (CB8259E)
Found in a 1968 Ferranti documentation, this circuit can be implemented with modern equivalent...
Binary to decimal converter (CB6583E)
This circuit is from an old American documentation using as indicators for the flip-flops neon...