Solid state relay (CB8518E)

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

Power Failure Indicator (CB6113E)
This circuit can be found in a 1970 Motorola documentation. The circuit can be implemented with general...
Isolated voltage sensor (CB8900E)
This shield circuit with an optical coupler was found in an 90s EDN. The circuit can be used with...
Automotive Voltage Regulator (CB1442E )
This circuit is from 1977 documentation, and high current equivalent transistor must be used. The...