Found in Ferranti's 1968 documentation, this circuit uses a Darlington photo transistor to drive a 12V relay. The circuit can be implemented with modern equivalent components.
This constant current source is from the LM11's own factory manual used in the application. The circuit is...
This circuit was found in documentation from the 1970s. However, it can be implemented with modern...
This circuit can work with almost any JFET. The circuit is from an Electronics Now from April...