We found this circuit in the 1983 edition of the Electronics Experimenter handbook. The circuit uses components that are common today, although many admit equivalents.
We found this circuit that uses a thermistor as a sensor from the 1991 Electronics Experimenter Handbook....
This unusual output stage was found in the October 1974 issue of Radio Electronics magazine. The...
This circuit is from a 1998 Electronics Now and can be easily assembled since it uses a common...