Solid state relay (CB8518E)

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

Visual dialing indicator (CB9296E)
Used with telephones at the time, this circuit was found in Popular Electronics from the 90s. The...
Capacitive Touch Switch (CB13154E)
Unlike the CIR4620 circuit, the circuit shown in the figure operates by capacitance. This means...
Constant Current Source (CB6628E)
This 1 A circuit was found in a Philips documentation from 1966. The transistor is of the time,...