This circuit is from Motorola's Linear Interface ICs from 1993. The MC1723 is the equivalent of the well-known 723. The transistor supports equivalents.
This circuit was found in a 1982 Maplin documentation. The configuration applies to almost any JFET....
This circuit is a sensor for photodiodes that can be used in optical couplers, encoders and other...
This circuit was found in an American publication from the 60's. The transistor is made of...