This circuit was found in the March 1984 issue of Radio Electronics magazine. The sensor is a transistor. The module is a common type at the time.
This circuit monitors the temperature of soldering irons, taking them when necessary to a low...
The traditional circuit was taken from a French magazine Radio Plans that no longer exists but can...
In this circuit the CA3140, an operational amplifier, is used as a comparator with the zener diode...