We found this circuit in the 1989 Radio Electronics Experimenter. The circuit uses common components, and the thermistor is supposed to determine the value of the trim potentiometer.
The transistors of this old circuit from the 60s can be the BC548, in a current version. The...
This electronic soldering gun circuit was found in the December 1998 Electronics Now magazine. The article...
This circuit was found in an American documentation from the 90's. What it does is provide at the...