This circuit was found in a Signetics documentation from the 1980s. Next to the figure are the waveforms of the generated signals. The transistor admits equivalent.
When the temperature rises above the value adjusted by P1 the relay triggers on. The rated voltage for the...
This circuit was found in a Popular Electronics of the 90s. We can build it based on modern...
We found this circuit in a 1965 publication by General Electric. The zener is 8.2 V x 1 W and the...