This circuit also detects IR, providing LED indication. The circuit is used to indicate humidity in bench tests. We found it in the Radio Electronics magazine of February 1990.
This nonlinear gain circuit was found in a 1965 Electronic Design. The configuration can be used...
This circuit adds an amplifying transistor that can supply loads of up to 250 mA. The circuit is...
I found this circuit in a 1992 Electronics Experimenter Handbook. The circuit can be easily...