Found in a 1969 EEE, this circuit is based on an operational amplifier of the time and on old type MOSFETs. The components support modern equivalents.
This circuit can be found in a 1970 Motorola documentation. The circuit can be implemented with general...
This shield circuit with an optical coupler was found in an 90s EDN. The circuit can be used with...
This circuit is from 1977 documentation, and high current equivalent transistor must be used. The...