This adjustable circuit from 0 to 200 nA was found in a 90's EDN. The components can still be found relatively easily, as they are CMOS.
This circuit was found in the Electronics Experimenter Handbook from 1991. The sensor is a diode...
This circuit can be used on audio, video, or data links to receive modulated infrared signals. The gain is...
With this circuit it is possible to obtain a voltage modulated in amplitude with a maximum current of...